Historic Homes Guide

8/3/2019 Historic Homes Guide

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BUILDING TECHNOLOGIES PROGRAM

Energy Performance Techniques

and Technologies:

Preserving Historic Homes

BUILDING AMERICA BEST PRACTICES SERIESVOLUME 13.

PREPARED BY

Pacific Northwest National Laboratory

& Kaufman Heritage Conservation

February 28, 2011

R

February 28, 2011 PNNL-20185


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BUILDING AMERICA BEST PRACTICES SERIES

Energy Performance Techniques

and Technologies:

Preserving Historic Homes

PREPARED BY

Pacific Northwest National Laboratory

Michelle Britt, Michael C. Baechler,

Theresa Gilbride, Marye Hefty,

Erin Makela, and Elaine Schneider

and

Kaufman Heritage Conservation

Ned Kaufman, Ph.D.

February 28, 2011

Prepared for the U.S. Department of Energy

under Contract DE-AC05-76RLO 1830

PNNL-20185

This report was prepared as an account of work sponsored by an agency of theUnited States Government. Neither the United States Government nor any agency

thereof, nor Battelle Memorial Institute, nor any of their employees, makes any

warranty, express or implied, or assumes any legal liability or responsibility for the

accuracy, completeness, or usefulness of any information, apparatus, product, or

process disclosed, or represents that its use would not infringe privately owned

rights. Reference herein to any specific commercial product, process, or service by

trade name, trademark, manufacturer, or otherwise does not necessarily constitute

or imply its endorsement, recommendation, or favoring by the United States

Government or any agency thereof, or Battelle Memorial Institute. The views and

opinions of authors expressed herein do not necessarily state or reflect those of

the United States Government or any agency thereof.


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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES

R

You can learn more about Building

America and download additional copies

o this document, other best practices,

research reports, and case studies at

www.buildingamerica.gov

Preface

This guide is a resource to help contractors renovate historichouses, while addressing issues such as building durability, indoor

air quality, and occupant health, saety, and comort. The best

practices described in this document are based on the results

o research and demonstration projects conducted by Building

Americas research teams. Building America brings together the

nations leading building scientists with over 300 production

builders to develop, test, and apply innovative, energy-efcient

construction practices.

Acknowledgments

The U.S. Department o Energys (DOEs) Building America

Program comprises public-private partnerships that conduct

systems research to improve overall house perormance, increase

housing durability and comort, reduce energy use, and increase

energy security or Americas homeowners.

Program activities ocus on fnding solutions or both new and

existing homes, as well as integrating clean onsite energy systems

that will allow the homebuilding industry to provide homes

that produce more energy than they use. In addition to DOEmanagement and sta, the Building America Program includes

15 consortia, our national laboratories, and hundreds o builders,

research organizations, manuacturers, and service providers.

The DOE Building America Program unded the development

o this guide. DOE also unded the Building America consortia

and national laboratories to conduct the research that orms the

basis or these recommendations. The consortia have taken on the

hard work o applied research, feld testing, training builders, and

transorming results into building practices. Numerous drawings,

descriptions, photos, and case studies originated with these research

partners. Examples rom these partners are used throughout this

guide to illustrate construction best practices.

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Contents

Preface ............................................................................................................................................................................i

Acknowledgments ....................................................................................................................................................i

1. Introduction............................................................................................................................................................1

2. Background: The Historic Building Context ........................................................................................3

Identification and Preservation of Historic Places...............................................................................4

Related Local and State Resources ............................................................................................................ 5

Building Codes ...................................................................................................................................................... 6

Preservation Project Classifications and Related Standards ......................................................... 7

3. Planning the Historic House Whole-House Energy Retrofit .......................................................9

The Energy Audit: A Vital Step in Retrofitting a Historic House ................................................ 10

Finding a Contractor to Retrofit a Historic House .............................................................................. 11

4. Historic House Upgrades ..............................................................................................................................12

Making the Most of the Potential of the Original Design ................................................................12

Air Sealing..............................................................................................................................................................13

Insulation Moisture Issues in the Attic and Basement ......................................................................15

Roofs.........................................................................................................................................................................16

Walls ..........................................................................................................................................................................18

Windows .................................................................................................................................................................19

Systems for Heating and Cooling a House ............................................................................................21

Lighting ..................................................................................................................................................................24

Other Considerations During an Energy Retrofit ..............................................................................25

Porches ...................................................................................................................................................................25

Landscaping and Siting ................................................................................................................................25

Seismic Retrofits ................................................................................................................................................26

5. Conclusion ...........................................................................................................................................................27

References.................................................................................................................................................................28

Appendix Health and Safety Concerns ................................................................................................30

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1. Introduction

The U.S. Department o Energys (DOEs) Building America

Program is an industry-driven research program that promotes the

accelerated development and adoption o advanced building energy

technologies in new and existing homes. The program gives home

builders and remodelers access to the nations leading building science

developments to build high-perormance homes that use less energy,

are more comortable, healthier to live in, and long lasting. This guide

is a resource or contractors and owners o historic houses who want

to improve the energy efciency while protecting historic character.

Although older buildings require attention and maintenance, they

repay the eort as assets that gain value over time. More and more,

homeowners value historic houses or their appealing aesthetic

character, liestyle advantages, and quality o lie. Depending on the

circumstances, these advantages may include beautiul ornamentation,

spacious room proportions, natural lighting, outdoor spaces, and

not least o alla eeling o history, tradition, and permanence.

Furthermore, time has shown that even the most unappreciated historic

styles eventually become popular; so, even i you have mixed eelings

about the appearance and design o a historic house, bear in mind

beore doing anything to diminish its historic character, that the next

occupants may love that styleand that may aect the selling price.

Special energy-retroftting challenges include preserving the homes

historic eatures, being aware o and adhering to regulations related

to historic designations, and addressing health and saety issues.

Building Americas research provides feld-tested approaches to help

address these challenges.

Sponsored by the U.S. Department

o Energy, the Building America

Program is industry-driven

research designed to accelerate

the development and adoption o

advanced building energy technologies

in new and existing homes (or more

inormation, see www.buildingamerica.gov.) Building Americas renovation

case studies illustrate proven

techniques applied to historic houses

in a variety o climates (or published

examples, see www.eere.energy.

gov/buildings/building_america/

climate_specific_publications.html).

Retrofitting homes that are designated

as historic may require a ormal

review process, but all homes deserve

a thoughtul approach to maintaining

their character.

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Retroftting homes that are designated as historic may require a

ormal review process, but all homes deserve a thoughtul approach

to maintaining their character. I you are a contractor, share this

guide with your clients so they can understand how you will make

their homes more comortable, durable, and energy efcient, while

respecting the homes historic qualities.

Following Building America-sponsored research, this document

ocuses on planning energy-efcient improvements or historic

houses by combining energy-efcient best practices with theprocess o historic renovation. The background or retroftting

and preserving older homes that may be designated as historic is

introduced. Steps to consider when planning a whole-house energy

retroft are highlighted. Strategies or maximizing the potential

energy efciency o an original house design and preserving its

character are presented. Aspects o retroftting a historic house

while preserving its character are addressed. Finally, the document

describes health and saety concerns related to past building

materials and practices. Reer to the resources cited throughout

this guide or additional inormation. This document does not

delve into the details o installation techniques. These practicesvary depending on construction materials, methods, and climate

zones, but reerences are provided so readers can access

installation inormation.

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2. Background:

The Historic Building Context

Improving energy perormance using Building Americas quality-

management practices and whole-house energy approach helps

deliver more energy-efcient and durable historic houses. The

historic nature o a home requires additional thought and sensitivity

to its construction and design eatures. When contemplating a historic

house remodel, it is important to determine whether there is any

possibility the property may be historically signifcant. Contact the

local building and planning departments to inquire about a local

historic preservation ordinance and whether:

THE HOME IS ELIGIBLE FOR LISTING IN THE

NATIONAL REGISTER OF HISTORIC PLACES

THE PROPERTY IS LOCATED WITHIN A HISTORICNEIGHBORHOOD OR DISTRICT

ANY LOCAL OR STATE HISTORIC ORDINANCES APPLY.

Understanding the regulatory requirements or preserving the

character-defning eatures o the home is as important as assessing

the homes inherent energy-conserving potential. It is important

to improve historic houses through maintenance, upgrading, and

environmental retroftting, but do not destroy its historic abric

and regret it later.

Because eective retroftting considers the historic character o ahome and the materials used to construct it, the builder may need

to coner with a historic preservation consultant. The State Historic

Preservation Ofce and local historic preservation ofce, society, or

commission may be able to identiy preservation design consultants

and restoration contractors who have experience with similar

projects. As preservationists, they want to preserve historic structures

rom demolition or degradation. They can help determine how to

best blend retroftting additions with the existing decorative details

and historic eatures o the home without damaging its character.

Builders need to be amiliar with the identifcation and preservation

o historic houses, related state and local resources, how codes might

aect retroftting, and any ederal permitting issues. I working with

preservationists on the project team, they also need to share a common

language as they work together to assess, plan, and decide how to

retroft the home. This section provides an overview o these needs.

www.nps.gov/nr/publications/index.htm

A good reerence or anyone

considering working with a historic

house is the National Register

Bulletin 15, How to Apply the

National Register Criteria for

Evaluation, which is available both

in print and online (http://www.nps.

gov/nr/publications/bulletins/nrb15/ ).

The National Park Service also

developed The Secretary o the

Interiors Standards or the Treatment

o Historic Properties with Guidelines

or Preserving, Rehabilitating,

Restoring, and Reconstructing

Historic Homes (hereater Secretarys

Standards; see www.nps.gov/history/

hps/tps/standards_guidelines.

htm). These standards and design

guidelines have been adopted by

state preservation agencies and

by many local ordinances and

programs (see www.energysavers.

gov/your_home/energy_audits/

index.cm/mytopic=11160 and http://

apps1.eere.energy.gov/buildings/

publications/pds/building_america/

ba_airsealing_report.pd).

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The [National Register]criteria do not describeexceptional, nor should they.

Exceptional, by its own definition,

cannot be ully catalogued or

anticipated. It may reflect the

extraordinary impact o a political or

social event. It may be a unction o

the relative age o a community and its

perceptions o old and new. It may be

represented by a building or structure

whose developmental or design value

is quickly recognized as historically

significant by the architectural or

engineering proession. It may be

reflected in a range o resources orwhich a community has an unusually

strong associative attachment.

For more inormation go to

www.nps.gov/history/nr/publications/

bulletins/nrb22/nrb22_I.htm

Identification and Preservation of Historic Places

The National Register o Historic Places (NRHP or National

Register)a division o the National Park Service (NPS)is

the authority on the topic o historic buildings. According to

the National Register criteria, homes over 50 years old may beconsidered historic i they were designed by a master architect,

have high aesthetic value, typiy a style or type o construction,

or are associated with signifcant individuals or historic trends.

In particular, the National Register criteria (www.nps.gov/nr/

publications/bulletins/nrb15/nrb15_2.htm) or evaluation o

historic sites state that:

The quality o signifcance in American history, architecture,

archaeology, engineering, and culture is present in districts, sites,

buildings, structures, and objects that possess integrity o location,

design, setting, materials, workmanship, eeling, and association, and:

THAT ARE ASSOCIATED WITH EVENTS that have made a

signifcant contribution to the broad patterns o our history; or

THAT ARE ASSOCIATED WITH THE LIVES o signifcant

persons in or past; or

THAT EMBODY THE DISTINCTIVE CHARACTERISTICS

o a type, period, or method o construction, or that represent

the work o a master, or that possess high artistic values, or

that represent a signifcant and distinguishable entity whose

components may lack individual distinction; or

THAT HAVE YIELDED OR MAY BE LIKELY TO YIELD

INFORMATION important in history or prehistory.

Homes under 50 years old can also be considered historic, but

they must have exceptional signifcance, with exceptional

reerring to the recognition o locally signifcant historic resources

that, by appearance or association with persons or events, provide

communities with a sense o past and place.

Homes located in historically designated neighborhoods must ollowthe requirements o the district even though specifc homes may not

meet the National Register criteria or eligibility.

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Related Local and State Resources

Beore making any energy improvements on a historic house, it is

important to ully understand the local, state, and ederal rules and

regulations that may govern changes to the historic house. Resources

or this inormation will vary by community, but start by contactingthe local building department, planning department, or historic

preservation ofce, society, or commission.

Although the criteria or defning historic may have been

developed by a ederal agency, it is most oten a local ordinance

that aects a project. I the jurisdiction has adopted by ordinance a

historic district, neighborhood, or a listing o historic houses, there

will be design guidelines to ollow, and a review board may need to

evaluate and approve the project beore a building permit may be

issued. The design review may carry extra costs that the contractor

or owner needs to actor into the budget.

For example, Eureka, Caliornia, originally settled in the mid-to late

1800s, has a heritage rich in lumber history, as is reected in its stock

o historic houses. I you were considering a project on an existing

home in Eureka, a call to the building or planning department (or

visit to its website: www.ci.eureka.ca.gov/depts/cd/permits_n_orms.asp)

would provide you with the Historic Preservation Ordinances

administered by the planning department. The inormation ound on

the website would tell you the Historic Preservation Commission is

responsible or the ollowing:

MAINTAINING A LIST OF LOCALLY, REGIONALLY, AND/OR

NATIONALLY SIGNIFICANT PROPERTIES AND DISTRICTS

called the Local Register o Historic Places.

HAVING AUTHORITY TO REVIEW APPLICATIONS

or additions, alteration, new construction, or demolition o all or

part o any structure, or landscape element (such as historic walls

and trees designated in the Historic Preservation Application) that

is located on a property listed in the Local Register o Historic Places.

HAVING THE AUTHORITY TO REVIEW AND MAKE

DECISIONS or all requests rom property owners to haveproperty placed in, or removed rom, the Local Register

o Historic Places (City o Eureka, Historic Preservation

Packet_2010).

The Magdalena Zanone House

Photo by Ron Kuhnel

The federal government does

not monitor the renovation

of privately funded historic

buildings. All regulations directly

afecting the project can be ound at

the local and state levels.

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A states SHPO contact inormation

can be ound through the National

Conerence o State Historic

Preservation O cers

(www.ncshpo.org/find/index.htm#top).

Regional and local guides will provide

inormation specific to the climate and

building materials o your region.

Be sure to confirm whether

local or regional design guides

exist; these will address local

climate conditions, locally specific

building methods and construction

practices over time, and oten local

building materials. For example, the

Sustainable Solutions or Historic

Houses in Northern Caliornia (www.

epa.gov/brownfields/sustain_plts/

reports/green_home_guide_final.pd),

addresses local climate issues and the

extensive use o redwood.

A resource for information

on building energy codes is

www.energycodes.gov.

I the planning or building department in your community uses a

similar approach, veriy whether the property in question is listed

and determine the associated process or application submittal,

review, public hearing, and decision by the commission prior to

being granted a building permit. Any or all o these steps will aect

the budget and design process.

As noted earlier, the ordinances that aect your project will be local,

but they oten rely on the Secretarys Standards or the treatment

o historic properties and guidelines or preserving, rehabilitating,

restoring, and reconstructing historic houses. In the Eureka,

Caliornia example, the review process includes a review o the

project to ensure consistency with the Secretarys Standards. Other

jurisdictions have developed their own standards you will need to

work with.

In addition to being aware o local restrictions, contact the StateHistoric Preservation Ofce (SHPO) to determine whether specifc

historic preservation design guidelines have been developed or your

state. The SHPO will also have inormation about any historical

surveys that have been completed or signifcant issues that have been

raised regarding the property you are considering renovating, and

can provide guidance in determining appropriate local resources.

Building Codes

Building permits may be required or energy improvements, and

the historic nature o the project may aect how the local buildingcodes apply to the project. The local code ofcial will provide

inormation about which codes have been adopted, and how

they are enorced relative to historic properties. For example, the

International Residential Code (IRC), which regulates construction

o single-amily houses, two-amily houses (duplexes), and buildings

consisting o three or more townhouse units, has been widely

adopted by jurisdictions nationwide.

The International Energy Conservation Code (IECC) has also

been widely adopted, and, like the IRC, it applies to building

additions, alterations, and repairs. However, as Section 101.1.2 o

the 2009 IECC states, properties that are listed, locally designated

as historic, or or which an opinion has been granted that it is

eligible to be listed are exempt rom the IECC. This is particularly

important when considering energy retroft projects, such as

windows and insulation.

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Historic Rehabilitations

Some jurisdictions have also adopted the International Existing

Building Code (IEBC), which is specifc to the use and reuse o

existing buildings, both residential and commercial, with Chapter 11

being specifc to historic buildings. It can be adopted by jurisdictions

as a means to codiy exceptions or historic buildings, and it can be

used in historic districts. An important distinction is that the IECC

excludes properties that could be listed, while the IEBC in general

applies to all historic properties (IEBC Chapter 11, Historic Buildings,applies only to listedproperties). I your jurisdiction has adopted

the IEBC, it is important to clariy which code will apply to your

project, because the IEBC, IECC, and IRC interace and overlap.

Preservation Project Classifications

and Related Standards

While contractors, building ofcials, and codes classiy projects as

additions, alterations, or repairs, depending on how extensive the

work is, preservationists typically classiy projects as preservation,

rehabilitation, restoration, or reconstruction, based on the goals

o the project and resulting impacts on the historic integrity o the

building. Beore the project begins, decisions need to be made about

how the property will be used, and i there are historic eatures that

can be retained. The National Park Service provides defnitions to

help determine the project classifcations. Note that additions and

alterations are both considered rehabilitation.

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The National Park Serviceidentifies five examplesto help illustrate theseclassifications.

Preservation Jacksonville NationalHistoric District (www.nps.gov/history/

hps/workingonthepast/case_studies/

jacksonville1.htm).

Rehabilitation 1 Baker Historic

District (www.nps.gov/history/hps/

workingonthepast/case_studies/

bakercity1.htm).

Rehabilitation 2 Ladds Addition

Historic District(www.nps.gov/history/


laddsaddition1.htm).

Restoration Monteith Historic

District (www.nps.gov/history/hps/

workingonthepast/case_studies/

monteith1.htm).

Reconstruction Oswald West

Coastal Retreat (www.nps.gov/history/


oswaldwest1.htm).

PRESERVATION ocuses on the maintenance, stabilization, and

repair o existing historic materials and retention o a propertys

orm as it has evolved over time. The historic eatures o the home

are not limited to one time period.

REHABILITATION acknowledges the need to alter or add to

a historic property to meet continuing or changing uses whileretaining the propertys historic character.

RESTORATION depicts a property at aparticular periodo time

in its history, while removing evidence o other periods. Restoring

a home is signifcantly dierent rom preserving or rehabilitating

it; less exibility is allowed in modernizing the building and

mixing elements rom various time periods. All modern changes to

the house are removed so that only one period is interpreted.

RECONSTRUCTION re-creates vanished or non-surviving

portions o a property or interpretive purposes. While houses asa whole arent typically reconstructed, independent elements o a

home, i.e., chimneys, porches, and so orth, can be and oten are

reconstructed.

It is important or contractors and homeowners to know how

to historically categorize their project, because the local or

state ordinance may base the design review o the project on

this classifcation and the applicable design guidelines rom the

Secretarys Standards.

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3. Planning the Historic House

Whole-House Energy Retrofit

Armed with inormation about any local ordinances or resources

and applicable building codes, planning or the retroft can begin.

Dont orget that, as old-ashioned as it may seem, a historic house

actually may have some environmental advantages that would be

hard to duplicate now: high-quality timber and windows, non-toxic

interior materials, heat-retaining masonry walls, mature shade trees,

through-ventilation, natural lighting, and so orth. Make these the

basis o your environmental retroft. But most o all, remember that

the mere act the house exists represents an environmental plus: you

dont have to build a new one! By retroftting the old one instead o

demolishing and building new, you are saving valuable materials,

reducing the amount o waste going into the landfll, andabove

allreducing carbon use and greenhouse gas emissions. As an addedbonus, you are enhancing the character o your community.

With these advantages in mind, consider how the retroft o the

historic home will dier rom retroftting a more contemporary

home. As with their modern counterparts, historic houses operate

as systems, but they work dierently rom contemporary homes,

and the systems vary depending on the era and style o architecture.

Understanding how these systems work and diagnosing their

needs are important steps in retroftting historic houses. Using an

integrated design approach is just as important in retrofts as it is in

new construction.

Building Americas systems approach to home design acknowledges

that as buildings become increasingly efcient, the interactions o

all o the homes components and subassemblies must be taken

into account to maximize perormance and avoid unintended

consequences. This whole-building approach recognizes that

changes in one or a ew components can dramatically change how

other components perorm, thereby aecting the overall building

energy use, comort, and durability. The integrated design process

used to improve the homes efciency and perormance can also be

applicable to remodeling and preserving historic houses.

Whole-building design suggests that a single change in a homes

structure or other systems can aect the rest o the home.

A key idea behind integrated

planning is that decisions about all

building systems, including equipment

selection, sizing, and placements,

are made within the design process,

not as aterthoughts in the field. The

decisions are made with the help o

analytical tools and the input o all

relevant disciplines. Rather than a linear

traditional process, the integrated

process involves looping in ongoing

input rom relevant sources.

The REGREEN Program is a

partnership between the American

Society o Interior Designers and U.S.

Green Building Council. The remodeling

guidelines address sustainable

remodeling practices and have been

applied to historic houses.

(www.regreenprogram.org).

42,226 homes have been built to

date using technologies and strategies

developed through Building America

research to construct high-quality,

energy-ef cient homes (http://apps1.

eere.energy.gov/buildings/building_

america/cm/project_locations.cm).

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Sealing air leaks may result in a need

or ventilation.

Experienced auditors or HVAC

contractors will conduct computer

simulationsACCA Manual J runsto

determine the how large the urnace

and air conditioner should be, based on

their inspection and findings.

For example, adding insulation and sealing air leaks can improve the

energy efciency o a home and improve its comort and durability.

However, every change made to the buildings envelope (walls, oors,

and ceiling) will aect the perormance, health, and saety o the

house. Sealing air leaks in the building envelope without providing

appropriate ventilation can cause pressure imbalances or negative

pressure inside the house. This negative pressure can cause freplaces,

urnaces, or other uel-burning appliances to release dangerous umes

into the house instead o exhausting them through chimneys or ues.

A home energy audit is conducted to help understand how a historic

house operates as a system and diagnose its particular needs. As

described below, a certifed contractor or auditor conducts the

audit and understands how historical systems work together to

keep a house operating as it should, and how changes will aect the

whole system.

The Energy Audit:

A Vital Step in Retrofitting a Historic House

Whole-house energy audits and inspections typically do the ollowing:

ASSESS how much energy the home consumes.

DETERMINE what measures to take to make the home more

energy efcient.

EVALUATE whether basic health and saety criteria are met.

The audit should be conducted by a certifed proessional, preerably

one with experience working with older homes and historic

preservation issues. (See the next section or how to fnd a certifed

auditor.) The auditor should frst confrm whether the National

Register has listed the home as a historic building. The audit will

then identiy problems that may, when corrected, save signifcant

amounts o money and energy over time. It will pinpoint where the

house is losing energy and determine the efciency o the homes

heating and cooling systems. The audit may also identiy ways to

conserve hot water and electricity.

A proessional auditor uses a variety o techniques and diagnostic

equipment to measure how a house perorms in ways that cannot

be seen by eyes alone. These tests may include a blower door test to

determine air leakage and house pressurization problems, tests to

detect drats and the eectiveness o the ducts, combustion saety

testing, and carbon monoxide sampling.

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The auditor will also estimate the costs o making various

improvements and will use a computer program to estimate the

annual savings expected rom each improvement. The cost o the

measures divided by the annual savings will provide the simple

payback or how many years the measures will take to pay or

themselves. Some energy measures may be as simple as stopping

unwanted heat transers by tightening leaky windows and doors.

Addressing the simple fxes will reduce the number o big-ticket fxes

needed. As experienced energy auditors know, or big-ticket fxes,

like new urnaces, it is important to weigh all o the available options

and install the smallest system needed.

The recommended energy-saving improvements derived rom

the audit results must be weighed against their impacts on the

historic character o the home and associated regulations, and any

retroftting decisions must take into account the unique costs o

historic house, such as custom windows. Note, the cost built into astandard audit may not capture the customized work needed or a

historic house.

More importantly, historic houses may contain open-combustion

appliances, such as gas-burning urnaces that use the air in the room

or the uel-burning process. Saety problems o open-combustion

appliances can be exacerbated when retroftting a home. When

cracks and leaks that once let in air are sealed, carbon monoxide and

air pollutants rom cleaning chemicals, combustion appliances, and

o-gassing household products can build up, creating an unhealthy

and even dangerous environment in the home.

These older homes also may have dry rot and moisture problems.

A certifed contractor ollows an auditing process that ensures

that any health, saety, and moisture problems are solved during

the whole-house energy retroft. With ongoing attention to the

homeowners health and saety, the contractor also identifes any

potential problems related to historically used materials, such as lead

and asbestos, that can cause major health problems (see Health and

Saety Concerns in the Appendix).

Finding a Contractor to Retrofit a Historic House

There are two nationally recognized energy certifcations or home

energy auditors and contractors: the Building Perormance Institute,

Inc. (BPI) Building Analyst certifcation and the Residential Energy

Services Network (RESNET) Home Energy Rating System Rater

certifcation. To date, BPI certifcation has ocused on understanding

the building science o retroftting existing homes, and BPI will

Atmospheric combustion

For more information about

home energy assessments and air

sealing, see www.energysavers.gov/

your_home/energy_audits/index.

cm/mytopic=11160 and the Building

America air sealing document (http://

apps1.eere.energy.gov/buildings/



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Shutters and awnings

be the best resource or historical home energy audits. BPI is a

nonproft organization that accredits auditors, contractors, and

other building proessionals. Auditors or building analysts specialize

in evaluating building systems and potential energy savings in

homes. The certifed BPI Building Analyst energy auditor has passed

both written and feld exams, and must recertiy every 3 years.

Contractors learn about building systems and are trained to install

energy-efciency measures. For more inormation about BPIs

standards and credentials or retroftting work, see www.BPI.org.

A certifed proessional home inspector who has experience working

with historic houses can be ound by contacting the local historical

society or suggestions. The Historic Building Inspectors Association

is another excellent resource depending on its availability in your

local area (also see http://inspecthistoric.org).

4. Historic House Upgrades

Improving energy efciency in a historic house involves paying

careul attention to how to make the most o its original design

eatures , ensuring the durability o the home, and preserving the

homes character during the remodel.

Making the Most of the

Potential of the Original Design

Building Americas research clearly indicates that climate zones aect

building and retroftting decisions. For example, radiant barriers are

not recommended in cold climates because o the moisture problems

they can cause. Historic builders intuitively understood some o these

climate-specifc eatures, and most o the eatures should be retained

during the energy retroft. For example, builders oten incorporated

eatures into the site and building design that helped moderate interior

temperatures or provided or comortable outdoor living areas

eatures like operable windows, awnings, heat-retaining masonry

walls, high ceilings, through-ventilation, shade trees, and so orth.

These eatures are still the basis o good design, and contemporary

homeowners will beneft rom maximizing their potential in terms ocomort or energy savings, while also retaining the historic character

o the home. The National Trust or Historic Preservation (NTHP)

identifes the ollowing historically useul cold and hot climate eatures

(also see www.preservationnation.org):

SHUTTERS AND AWNINGS used in both hot and cold climates,

with adjustable louvers allow or air circulation and block solar

gain on hot days. Operable shutters reduce drats on colder days

and block solar gain on hot days. Post-Katrina construction in

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New Orleans and on the Gul Coast is seeing the reinstitution o

more historic louver shutters that admit air, while providing shade.

Removable or permanently attached awnings protect the windows

rom solar gain on hot days, allowing or winter solar gain.

OVERHANGS, EAVES, AND COVERED PORCHES provide

shaded outdoor living space and protect the walls rom the hotsummer sun and precipitation. I siding is being replaced, an

overhang could allow or the addition o exterior rigid oam to

help insulate the walls.

SEASONALLY SHADED INTERIOR COURTYARDS provide

outdoor living space or hot summer days and warm protected

areas on cooler days.

BRICK AND ADOBE provided thermal mass to moderate the

temperature swings, releasing heat gained during the day into the

cooler night.

CROSS VENTILATION is encouraged with the use o double-

hung windows both upstairs and downstairs, creating an air ow

through the house and exhausting hot air rom the upper story.

VEGETATION is used to provide windbreaks and provide shade

or the hot summer days. Evergreen trees provide year-round wind

protection while deciduous trees provide seasonal shade, allowing

or winter solar gain.

Taking advantage o retaining these eatures will beneft the

home by preserving its historic integrity, increasing the comorto the homeowners, and reducing the need or additional energy

efciency eatures.

Air Sealing

Whether a home is located in a hot and dry or very cold climate, one

o the least expensive and potentially most eective energy-retroftting

measures is air sealing. The Building Americas Best Practices Guide,

Air Sealing: A Guide or Contractors to Share with Homeowners (http://

apps1.eere.energy.gov/buildings/publications/pds/building_america/

ba_airsealing_report.pd), provides comprehensive guidance or air

sealing existing homes. The guide helps identiy ways to make homes

more comortable, more energy efcient, and healthier to live in.

It also identifes the steps to take to seal unwanted air leaks while

ensuring healthy levels o ventilation and avoiding sources o indoor

air pollution. Studies show that air-sealing measures described in the

guide can typically achieve whole-house energy savings o 10% to 20%

over pre-retroft energy usage. In older homes or homes with greater

air leakage, the savings may be much greater.

Miller placed rigid oam insulation and

a new three-coat stucco finish over the

original adobe walls but kept the historic

masonry parapet visible to retain the

homes southwestern character.

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The Building America Asdal case study

illustrated the use o rigid oam sealed in

place with spray oam to insulate the band

joists (top) and the use o spray oam

around piping and wiring holes (www.eere.

energy.gov/buildings/building_america/

cold_case_studies.html).

Establishing the continuity o the air barrier system o a building

is the goal o air sealing, which should be an integral part o all

aspects o the retroft rom roo to cellar to window repair. However,

it is important to remember the building is unctioning as a system,

and all parts o the system must work together to keep moisture

rom causing damage to the structure or being a health hazard to the

occupants. As an air quality issue, the growth o mold and mildew

may be exacerbated by the reduction in air leakage, but air sealing

in general does not inhibit drying o the structure, unless it results in

encapsulating the structure with vapor-impermeable material. Mold

and mildew growing in moist areas may cause allergic reactions

and damage building materials. I the air movement through the

structure was allowing parts o the structure to dry out, sealing the

building may require the addition o mechanical ventilation.

Two key examples o air sealing in historic houses and approaches

taken to avoid indoor air quality problems are described below.

Pittsburgh Depression Era Bungalow

The Building America Asdal Builders, LLC Pittsburgh Case Study

(Pittsburgh; http://apps1.eere.energy.gov/buildings/publications/pds /

building_america/ba_cs_retroft_asdal_builders.pd) demonstrates

the way one change can trigger another in the house as a system.

The renovators caulked the sill plates, air sealed the unfnished

basement walls, and sealed the band joists with spray oam and

rigid oam insulation. The extensive air sealing provided a very

tight house, demonstrated by blower door tests. However, the tight

house necessitated another stepproviding adequate combustionair. The natural gas boiler used combustion air drawn rom inside

the home, thereby drawing oxygen rom the living environmenta

health concern in tightly sealed homes. The solution was to install a

new boiler, with power venting drawing combustion air rom the

outside.

Newburgh 18th Century Brick

The Building America Habitat or Humanity, Newburgh, NewYork

Case Study (Habitat Newburgh; http://apps1.eere.energy.gov/

buildings/publications/pds/building_america/ba_cs_retroft_

newburgh_habitat.pd) illustrates how to handle historical elements

that are also air leakage problems. The goal was to reach a fnal

infltration rate o 0.60 air changes per hourthe ENERGY STAR

requirement or new homes. The freplace contributed to the air

leakage, but was a historical element o the home. The solution was

to close o the freplace and careully seal around it, but retain it as

a decorative element or its historical value.

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When air leakage is signifcantly reduced, mechanical air ventilation

may be necessary. American Society o Heating, Rerigerating and

Air-Conditioning, Inc. (ASHRAE) Standard 62.2 or ventilation

and acceptable indoor air quality in low-rise residential buildings

provides the related standards and guidelines (ASHRAE 2007).

Installing ENERGY STAR exhaust ans on timers can provide

adequate ventilation.

Insulation Moisture Issues

A second key energy-saving practice or existing homes is installing

increased insulation in basements, above-grade walls, and attics. The

energy audit will have provided inormation about air leakage, moisture

issues, and desired insulation levels. Attic and basement insulation,

in particular, can increase the energy efciency o a home without

damaging its historical integrity, and the installation o insulation oten

can occur without aecting architectural eatures or details. However,altering the air-sealing and thermal properties o attics and basements

can result in signifcant moisture issues. DOEs Building Technologies

Program Insulation Fact Sheet (www.ornl.gov/sci/roos+walls/

insulation/ins_06.html) describes the issue as ollows:

When moist air touches a cold surace, moisture may orm as

condensation. I moisture condenses inside a wall, or in your attic,

you will not be able to see the water, but it can cause a number o

problems. Adding insulation can either cause or cure a moisture

problem. When you insulate a wall, you change the temperature

inside the wall. That can mean that a surace inside the wall, suchas the sheathing behind your siding, will be much colder in the

winter than it was beore you insulated. This cold surace could

become a place where water vapor traveling through the wall

condenses and leads to trouble. The same thing can happen within

the attic or in a crawlspace or basement. With careul design the

new temperature profle could prevent condensation and help keep

your walls or attic drier than they would have been.

Massachusetts 1760 Cape

Basement walls may have historical signifcance, contributing to the

difculty o adding exterior insulation. Basement walls, typically

ound in colder climates, can present other specifc challenges as

demonstrated in The Building America National Grid Deep Energy

Retroft Pilot Program: Clark Residence, Belchertown, Maine (Clark

Residence; www.buildingscience.com/documents/case-studies /

cs-ma-ngrid-deep-energy-retroft?topic=resources/retrofts ). Prior

to the retroft, there were occasions o standing water in the

Clark Residence basement. Trenching, piping, and gravel mitigated

For more information on air

sealing, reer to Building Americas Best

Practices Guide, Air Sealing: A Guide or

Contractors to Share with Homeowners

(http://apps1.eere.energy.gov/buildings/



In the Clark Residence, the

basement is conditioned with 3 to

5 inches medium-density spray oam

insulation applied directly to field

stone and concrete oundation walls.

Spray oam insulation is painted with

ignition barrier paint. A 12-inch-high

strip o 2-inch oam insulation at the

slab edge provides a thermal break

and allows oundation walls to drain to

the sub-slab drainage system. Several

trenches with drainage pipes and filled

with gravel carry bulk water to drain.

The new cast concrete basement floor

slab is installed over 6-mil poly, 2-inchoam insulation, and a continuous bed

o gravel.

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The Building America New Bedord

Farmhouse case study illustrates significant

energy retrofits while maintaining thehistoric character o the building

(www.buildingscience.com).

The National Trust for Historic

Preservation oers guidance inweathering roos o historic houses

(www.preservationnation.org/issues/

weatherization/roofing/).

the drainage. The retroft solved a potential condensation problem

on the slab and walls by insulating with 3 to 5 inches o medium-

density spray oam applied directly to the feld stone and concrete

oundation walls and adding a gravel base, a vapor barrier, and rigid

insulation beneath the new slab.

Roofs

A leaky roo will set the stage or damage, decay, and potential

health and saety issues in a house. Repairing a leaky roo can

provide an opportunity to add insulation. The energy audit and roo

inspection should provide the inormation needed to determine the

perormance o the roo, identiying repair needs or the potential or

increasing insulation levels. The audit should answer key questions,

like those o the NTHPs Start with the Roo A Guide to Keeping

Weather Tight (www.preservationnation.org/issues/weatherization/

roofng/additional-resources/nthp_roofng.pd):

Is my roo energy efcient?

How do I know i my roo is ailing?

What type o roo orm is on my building?

When replacing my roo, do materials matter?

In addition to answering these questions, when planning to re-roo

consider how the pitch and materials o the roo distinguish its

historical period and character. In a historic house, the overallshape, pitch, and construction o the roo, as well as its raming

members may also have historic quality, because o the materials or

construction methods used. These elements may limit the available

options or adding insulation or other improvements.

Examples o reducing energy use by air sealing and insulating the

roos o historic houses are described below.

Massachusetts Mid-19th Century Farmhouse

The Building America Bedord Farmhouse High-Perormance

Retroft Prototype (Bedord Farmhouse; www.buildingscience.com/documents/case-studies/cold-climate-bedord-armhouse-retroft

case-study), demonstrates massive energy use reductions in a type

and age o building that is widespread in the region. The project

also demonstrates the application o specifc high perormance

techniques to an older building. By respecting and maintaining

the historic character o the building and elevating its aesthetics,

the project also allays concerns that a high perormance retroft

threatens the character and appeal o a neighborhood.

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The 150-year-old Bedord Farmhouse is located in the Building

America Cold and Very Cold Climate Zone, which necessitates

signifcant improvement o the insulation levels. The solution

or this structure was to seal and insulate the attic and basement

as conditioned spaces. The attic was unvented, and oil-aced

polyisocyanurate insulating sheathing was placed on top o the

existing repaired roo sheathing, while unaced fberglass batt

insulation was placed in the raters. The resulting R-56 insulation

contributed to an overall estimated 35% reduction in energy use

over the Building America benchmark and an estimated annual

savings o $930.

Tucson Adobe

The Building America John Wesley Miller Company renovation

o a historical adobe home in Tucson (Adobe renovation; http://


ba_cs_retroft_john_wesley_miller.pd) grappled with a very dierentclimate and roo type. Located in the Building America Hot and

Dry Climate Zone, the home has a traditional at roo design,

which required a dierent solution in energy retroftting. In this

case, the original roofng was removed rom the at roo assembly,

but the raming and plywood sheathing were retained. Two inches

o polyisocyanurate rigid insulation (R-13) were installed on top o

the sheathing, ollowed by a new built-up roo, which was painted

reective white or solar reectance in the hot and sunny climate.

Florida Victorian

The Florida Solar Energy Center (FSEC) dealt with the issue

o historic raming in its restoration case study o the Williams

home in Cooling Load Reduction and Air Conditioner Design

in a 19th Century Florida House Museum (Williams House; see

Chasar [2004] available at www.sec.uc.edu/en/publications/pd/

FSEC-CR-1508-05.pd). One o the project goals was to reduce the

cooling loads o the house, which necessitated the addition o attic

insulation. Although spray polyurethane oam products applied to

the roo deck would have provided both air sealing and insulation,

it would have hidden part o the historical eatures o the house and

the decision was made to add insulation at the ceiling level instead.

As exemplifed by the case studies, roofng solutions or energy

retrofts will vary with the climate zone, roo construction, and

historic details o the home.

(Top) The Building America New Bedord

Farmhouse case study sealed and insulated

the attic as a conditioned space, placing

oil-aced polyisocyanurate on top o theexisting repaired roo. Building Science

Corporation. 2010. Bedord Farmhouse

High Perormance Retrofit Prototype

(Case Study), (www.buildingscience.com),

Somerville, Massachusetts.

(Bottom) Blown-in insulation can be used

to dramatically increase insulation values.

Another resource for historicroof projects is the 1978 NPS

Preservation Brie 4: Roofing or

Historical Buildings (www.nps.gov/

history/hps/tps/bries/brie04.htm).

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(Top) The Building America Chesapeake

Habitat or Humanity case study

demonstrates a solution or brick walls:

installing rigid insulation between bricks

and raming, air sealing, and filling the new

cavity with batts (www.eere.energy.gov/

buildings/building_america/mixed_humid_

case_studies.html).

(Middle/Bottom) The Building AmericaSEER case study in New Jersey

demonstrated the use o blown-

in and oamed insulation under the

siding (http://apps1.eere.energy.gov/

buildings/publications/pds/building_

america/36474.pd).

Walls

Walls can be sources o air and moisture leaks, and in historical

homes they may be uninsulated. In addition to air sealing, an

energy retroft will seek opportunities or increasing the insulation

levels o exterior walls. However, insulating walls in historic housescan be challenging.

Chesapeake Habitat for Humanity

The Building America Chesapeake Habitat or Humanity Baltimore,

Maryland Case Study (Chesapeake Habitat; http://apps1.eere.energy.

gov/buildings/publications/pds/building_america/ba_cs_retroft_

chesapeake_habitat.pd) developed a solution or insulating brick-

walled homes. The technical directors on the projectSteven Winter

Associateswere seeking a solution to the thermal bridging that was

occurring when raming inside the above-grade walls and flling the

cavities with fberglass batts. Their R-21 wall solution was to install a1/2 inch o rigid insulation between the bricks and stud raming, air

seal the edges and gaps with oam, and then fll the new interior stud

wall with R-19 batts. The existing gap between the double brick wall

allowed or ventilation, so moisture did not penetrate to the oam.

New Jersey 19th Century

The Building America Strategies or Energy-Efcient Remodeling

2003 retroft in rural New Jersey (Drumheller and Wiehagen 2004;

http://apps1.eere.energy.gov/buildings/publications/pds/building_

america/36474.pd) demonstrates solutions or a dierent set o

issues. In this case, a 19th century home had uninsulated 2x4 walls,

with wood siding and partial interior sheathing. However, the siding

had deteriorated and needed to be replaced. The case study shows

that based on the existing wall conditions, two wall cavity insulation

choices were availablethe use o blown-in insulation materials or

oam-in-place insulation. Blown-in and oamed insulation materials

provide more o an opportunity to completely fll irregular wall

cavities and may be installed through small openings in the raming

bay. They also are particularly adaptable to insulating wall sections

that have coverings on both the exterior and interior o the raming

members. Additional insulation on the exterior o the raming wasalso considered because the siding was being replaced. The Building

America partners ultimately chose blown and oamed insulation in

the wall cavity and sheet insulation under the siding.

Another option or wood-clad buildings is the drill-and-fll

method o opening 2-inch holes and injecting fberglass or cellulose

insulation into the cavity, resulting in an R-13 to R-21 insulated wall,

depending on the cavity depth and type o insulation.

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Windows

The energy audit will have identifed moisture and/or air leakage

around windows and any other problems that exist with the current

windows. Window treatments may include the ollowing:

air sealing, ashing, and weatherstripping

repair and reconstruction

addition o storm windows

replacement with historically accurate replicas

replacement with wood windows o similar design (e.g., replacing

double hung with double hung outftted with similar material).

Which option is best suited to the project depends on the results o

the energy audit, climate, and the project objectivespreservation,

rehabilitation, or restoration. Because o the highly visible nature

o windows and their direct bearing on the historical integrity o

the building, the NTHP promotes rehabilitating existing windows

whenever possible. I there is water damage to the sills or around

the window, evaluate whether the window needs resetting with an

improved drainage plane.

As noted earlier, it is important to frst maximize the inherent

potential o the house to be energy efcient. Existing awnings or

shutters that provide appropriate shading, serve to ventilate the

(Left) Drill-and-fill wall insulation on a

house located in a Portland, Oregon histori

district. Typically narrow strips o siding are

removed beore drilling, and sealed holes

are hidden when siding is reinstalled.

(Right) Blown-in insulation can be installed

in walls rom the interior. Care must be take

to match existing wall finish textures.

The window may not be

the problem, but the installation

may be. The Building Science

Corporation, in Building Science

Digest-105: Understanding Drainage

Planes (https://www.buildingscience.

com/documents/digests/bsd-105

understanding-drainage-planes/files/

bsd-105_understanding_drainage_

planes.pd), provides a variety o

window installation solutions or

dierent wall types.

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(Top) The Building America Clark

Residence retrofit case study demonstrates

the use o high-quality storm windows

(www.buildingscience.com) a solution to

improving window e ciency.

(Bottom) An Insulated Glass Unit (IGU) is

installed as a storm window over stained

glass. Photo by Bruce Kinzey

There is a need to demon

strate there are ways to beenergy efficient without

replacing windows, and that

historic buildings oten have natural

advantages to ventilate, heat, and

cool, said Rock Island Preservation

Commission Chairman Robert Braun.

home, and/or are part o the historic character o the house should

not be removed but maintained in good operating condition. I the

original design included these eatures but they are no longer part o

the structure, consider replacing them in a manner consistent with

the Secretarys Standards or the treatment o historic properties

and guidelines or preserving, rehabilitating, restoring, and

reconstructing historic houses.

Massachusetts 1760 Cape

The Clark Residence retroft (www.buildingscience.com/documents/

case-studies/cs-ma-ngrid-deep-energy-retroft?topic=resources/

retrofts) demonstrates how a Cape Cod home, circa 1760, can be

energy efcient and retain a good deal o its historic character.

The original windows had been replaced with relatively new

wood-rame windows, but they did not oer sufcient thermal

perormance and the homeowners were disinclined to replace

them. Building Science Corporation, a Building America team,determined that adding high quality exterior storm windows

oered the best combination o improved thermal perormance,

interior condensation control, and exterior rain shielding or

the windows. The resulting window specifcations included new

storm windows over existing wood-ramed, double-glazed, low-E

windows. When considering the house as a system, in this case

there was concern that air-impermeable and vapor-retarding

insulation, would put the structure at risk because it could no

longer dry to the inside. To avoid this problem, the renovators

installed new ashing and made other corrections to the water

drainage plane to keep the water away rom the structure.

The Color of Glass

An issue to consider when adding storm windows or replacing

windows is the color o the glass. Glass color will inuence the

quality o light within a building and can also contrast with

other glass already present or being added to the building. Oten,

operable windows like casements and sliders are replaced and

storm windows are added to fxed windows. The storm and the

replacement windows may incorporate glass rom dierent sources

and appear dierent i compared side-by-side. The same type o

comparison may be true when replacement or storm windows

are installed near windows that are let as-is. Perhaps more

importantly, tinted glass may obscure existing window eatures.

Discuss this issue with the window supplier to ensure the selection

o consistent glass color, and glass that does not obscure original

window eatures.

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Systems for Heating and Cooling a House

Pasadena Ranch House

The comprehensive energy audit on the Building America Hartman

Baldwin Design/Build, Pasadena, Caliornia retroft (Pasadena;

http://www1.eere.energy.gov/buildings/building_america/hot_dry_mixed_case_studies.html) provided direction beore the team began

sealing the building shell and installing a new HVAC system. The

homeowner was surprised to learn that the bottom o the return

plenum had rusted out and was open to the crawlspace oor.

Not all audits will point to such clear problems, but they will

provide the inormation to address the heating and cooling system

needs. Depending upon the age o the home, it may have a heating

and cooling system that is very dierent rom most contemporary

homesone that may have relied heavily on passive heating or

cooling, such as shading and cross ventilation rom open windows.Beore installing a new system, ensure that these passive historic

heating and cooling eatures have been maximized. Also ensure that

the recommended energy retroftting derived rom the energy audit

has been completed.

I the home has open chases, oor vents, or built-in chimneys

to provide air ow and ventilation, make sure they are currently

being used as efciently as possible. Retain the associated grilles or

other fnishing eatures or their historical character. Even unused

radiators may contribute to the historic character o the house, so

consider retaining them.

Ceiling ans help with both cooling and heating. Window ans can

exhaust hot air or bring cool air in overnight. Whole-house ans,

installed over stairway halls or elsewhere, exhaust hot air that rises

through the house, while pulling in resh air rom the ground level

where it is coolest. Ordinary room ans can make a remarkable

dierence in the summer, and the dierence in terms o energy use

can be signifcant.

In homes with existing central heating and cooling systems,

sealing or repairing the existing duct system may reap signifcantbenefts. As noted in the Building America Best Practices Guide,

Air Sealing: A Guide or Contractors to Share with Homeowners,

all ducts should be sealed, especially in attics, vented crawlspaces,

and rim areas. In older homes, wall cavities and oor joist cavities

are sometimes used as return ducts to bring air rom the return

registers back to the air-handler unit, but these building cavities are

The Building America Pasadena Ranch

House case study demonstrates the

value o beginning with an energy

audit. Illustrated here is an open plenum

discovered in the crawlspace (www.eere.

energy.gov/buildings/building_america/

hot_dry_mixed_case_studies.html).

All ducts should be sealed,

especially in attics, vented crawlspaces,

and rim areas. For more inormation,

see Building Americas Air Sealing:

A Guide or Contractors to Sharewith Homeowners (http://apps1.eere.

energy.gov/buildings/publications/

pds/building_america/ba_airsealing_

report.pd).

February 28, 2011
http://www1.eere.energy.gov/buildings/building_america/hot_dryhttp://www.eere/http://apps1.eere/http://www1.eere.energy.gov/buildings/building_america/hot_dryhttp://www.eere/http://apps1.eere/


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This historic home uses Unicos Small Duct

High Velocity HVAC equipment, to heat

and cool the home without modifications

to the original historic structure.

Photo by Unico

rarely air sealed and should be replaced with sealed ducts. Reer

to the aorementioned Building America Best Practices Guide or

specifc guidance on repairing and sealing existing systems (http://



Briey, three situations a renovator may ace when replacing a

system include the need to replace the duct system, replace electric

resistance or steam heating, or add air cooling. The limitations o

replacing existing systems, based in part on U.S. Department o

Energy Energy Efciency and Renewable Energy, Energy Savers:

Limitations When Replacing Existing Heating Systems (www.

energysavers.gov/your_home/space_heating_cooling/index.cm/

mytopic=12320), are highlighted below:

INSTALLING NEW DUCT SYSTEMS. When intending to install

new duct systems in a historic house, plan the air delivery system

careully. It should be efcient without changing the homes

historic character by introducing unsightly transoms, dropped

ceilings, etc. While new homes should always have their urnaces

and air handlers located in a conditioned space, this is not always

possible in historic houses. However, i the attic and/or basement/

crawlspace have been converted to conditioned space these spaces

will generally be the best locations or the equipment and ducts.

In some multi-story homes, however, a dierent option will be

needed. High-velocity mini-ducts may provide a solution, because

they orce air through plastic eeder ducts that are only 2 inches

in diameter. These ducts can be easily threaded through cavities in

walls, oors, and ceilings.

A downside o installing mini-ducts is that they generally require

more outlets (2-inch-diameter round ducts): roughly fve outlets

per ton o cooling, or one outlet or every 2400 Btu o heating.

These outlets will likely result in higher costs to install the system.

When installing mini ducts, keep in mind the appearance o the

house during preliminary planning. Outlets can stand out in a

room and their placement is very important, especially when

preserving or restoring a home. Consider putting the outlets in the

corners o oors and ceilings.



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REPLACING ELECTRIC RESISTANCE OR STEAM HEATING

WITH HOT-WATER BASEBOARD HEATING. In homes

without ducts, replacing electric resistance baseboard heaters or

steam systems with a hot-water baseboard system can avoid the

need or new ducts, and may limit the overall cost. Replacing an

electric resistance system usually will require extensive plumbing,

but installing it may be less problematic than installing new ducts.

Converting steam systems to hot water is generally only easible in

two-pipe steam systems.

ADDING AIR COOLING TO A HEATED FORCED-AIR

(DUCT) SYSTEM AND INSTALLING DUCTS. This can be

accomplished by adding central air to a orced-air system or

switching to a heat pump. System sizing should not be done beore

the energy audit has been carried out and all weatherization has

been completed. While heat pumps typically require larger duct

systems, duct systems in existing homes are oten unnecessarily

large and rather than being energy efcient, end up wasting energy

and money. Once the home has been made more efcient the sizing

may be appropriate.

Massachusetts Mid-19th Century Farmhouse

In the case o the Bedord Farmhouse, the retroft accomplished

its goals by insulating the attic and basement to create conditioned

spaces. The gas urnace was installed in the newly conditioned space,

and the air handler and distribution system were located entirely

within conditioned space, using sheet metal trunks and run-outs and

ducted returns rom the upstairs bedrooms.

Florida Victorian

The Williams home project aced a dierent challenge to maximize

the original design o passive cooling. Because the home was to

be used as a museum with fxed hours throughout the summer

months, the decision was made to provide cooling. First, the natural

system was optimized, reducing the amount o humidity and dry

air loss through air sealing, insulation, and shading/reectivity. The

builder used the high-velocity mini-duct distribution system, citing

two advantages in its situationbecause the outlets are smaller,

they are less noticeable, and the delivered air temperature is colderthan conventional systems, which improves the dehumidifcation

properties o the cooled air. Dehumidifcation was importantas

the builder energy-retroft the home and added air conditioning it

changed the system, aecting the way temperatures and humidity

moved through the building and building envelope.

Building Americas BedfordFarmhouse High-Performance

Retrofit Prototype accomplished

its retrofitting goals by locating the gas

urnace in the conditioned attic and

locating the air-handler and distribution

systems within conditioned space(or more inormation, see

www.buildingscience.com/documents/

case-studies/cold-climate-bedord

armhouse-retrofit-case-study).

The Williams home project

Cooling Load Reduction and Air

Conditioner Design in a 19th Century

Florida House Museumoptimized the

homes natural system and installed a

high-velocity, mini-duct distribution

system (or more inormation, see

www.sec.uc.edu/en/publications/pd/

FSEC-CR-1508-05.pd).

February 28, 2011
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When retrofitting with can lights, make

sure they are insulation-contact air tight

(ICAT) and labeled as meeting ASTM E283

when tested at 1.57 ps (75 Pa) pressure

diferential with no more than 2.0 cm o

air movement and sealed with a gasket

or caulk between the housing and interior

wall or ceiling covering.

Lighting Options

Incandescent lighting has traditionallydelivered about 85% o household illumina

tion. Incandescent lamps operate without a

ballast, are dimmable and instantly control

lable, and light up instantly. Most amiliar are

the standard pear-shaped, screw-in A-type

incandescent light bulbs. They produce a

warm light and provide excellent color qual

ity. They have a low ecacy compared to all

other lighting options (10 to 17 lumens per

watt) and a short average operating lie (750

to 2500 hours).

Fluorescent lamps use 25% to 35% o

the energy used by incandescent lamps

to provide the same amount o illumination (ecacy o 100 lumens per watt)

and last about 10 times longer (7,000 to

24,000 hours). Improvements in technol

ogy have resulted in fluorescent lamps with

color temperature and color rendition that

are comparable to incandescent lamps.

LED lights use 35% to 50% o the energy

used by an incandescent lamp to provide

the same amount o illumination (luminaire

ecacy o about 70 lumens per watt) and

last longer than incandescent or fluorescent

bulbs. (Good-quality white LEDs in well-

designed fixtures are expected to have auseul lie o 30,000 to 50,000 hours.) LED

device ecacy doesnt tell the whole story.

Good LED system and luminaire design is

imperative to energy-e cient LED lighting

fixtures. For example, a replacement LED

downlight combines thermal management

and optical design to produce up to 700

lumens using only 6 to 7 watts.

Citation: rom LED Basics: What retailers, energy e ciencyadvocates, and consumers need to know to make inormed

buying decisions (2 pages, November 2009; www.eere.

energy.gov/buildings/ssl/actsheets.html).

Lighting

Artifcial lighting consumes almost 15% o household electricity,

and signifcant energy savings can be achieved by retroftting a

homes lighting. Note that older homes started out with no lighting

or gas lighting and have already been modifed at least once. Useo new lighting technologies can reduce lighting energy use in

homes by 50% to 75%. Advances in lighting controls oer urther

energy savings by reducing the amount o time lights are on but

not serving a useul purpose. Advanced lighting controls also oer

a new amenitylights that come on automatically when they are

needed (http://apps1.eere.energy.gov/buildings/publications/pds/

building_america/26467.pd).

Unlike other energy-retroftting techniques, lighting changes have

ewer impacts on other house systems; the biggest impact is on

reducing the cooling load in summer. New compact uorescentlamps can be ound or many socket styles and sizes. Their use will

reduce the heating load and the energy budget o the home. Consider

installing and using task lighting and LED applications that will

enhance the eel o the room. LEDs are particularly appropriate

or downlighting, under-cabinet lighting, and specifc task lighting.

Furthermore, use o a wide range o sensor light fxtures on the

market, i used properly, will help to conserve energy.

Existing light fxtures are an important element o a historic house

whether or not they are unctional. For example, unused gas light

fxtures can be retained as historic elements o decor.

Finally, careul trimming o exterior landscaping elements that

detract rom the natural interior lighting also should be considered

to improve lighting in the home.

Solid-State Lighting Research:

Solid-state lighting technologies are changing and improving rapidly, and

products arriving on the market exhibit a wide range o perormance.

The DOE Commercially Available LED Product Evaluation and Reporting

(CALiPER) program provides reliable unbiased product perormance

inormation (www.eere.energy.gov/buildings/ssl/caliper.html).

http://www.eere/http://apps1.eere.energy.gov/buildings/publications/pdfshttp://www.eere/http://apps1.eere.energy.gov/buildings/publications/pdfs


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Other Considerations During an Energy Retrofit

Several retroftting options wont necessarily be the ocus o the

energy audit, but they should be considered in an energy retroft,

e.g., porches, landscaping, and seismic retrofts

Porches

Porches should not be ignored when considering ways to make

a home more energy efcient; efciencies can be gained rom

insulating and air sealing points where porch roos intersect house

walls. Beore adding insulation, make sure the drainage plane is not

allowing water to run between the porch and house, or within the

porch roo structure.

There are also simple ways o making a porch a more temperate and

attractive place to spend time. For example, installing an awning orplanting shade trees can transorm the space. Adding a ceiling can

keep the heat rom bearing down on occupants. Installing a ceiling

an can ensure air movement, without detracting rom the general

eel and historical quality o the porch.

Originally designed or shade and shelter rom the elements and

outdoor living area, porches are sometimes walled in and fnished to

provide additional interior space. Doing this may detract rom the

ow o spaces within the home and change its historic character. I

additional interior space is needed, consider adding it where it will

have less o an impact on the historic image that the home presentsto the street. I a glassed-in ront porch already exists, consider

returning it to its original confguration. This will enhance the

historic character o the house while providing an attractive, shaded

outdoor space.

Landscaping and Siting

I the property landscaping has been maintained over the lie o

the home, it will likely include trees and other eatures that are

aesthetically compatible with the home and provide shade and wind

breaks. Historic landscape eatures may also include valuable oreven irreplaceable plant material, such as mature trees and owering

shrubs that would take many decades to replicate. Beore removing

historic plantings, consider that they are there or a reason and they

are part o the homes historic character.

The Building America Tucson Adobe case

study retained the historic landscaping

with plants and ground cover that require

minimum irrigation (www.eere.energy.

gov/buildings/building_america/hot_dry_

mixed_case_studies.html).

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRE

Historic Homes Guide

Documents

Transcript of Historic Homes Guide