Meditch Murphey Architects 6900 Wisconsin Ave – Suite 500phone: (301) 657-9400 Bethesda, MD 20815...

Meditch Murphey Architects Meditch Murphey Architects6900 Wisconsin Ave – Suite 500 phone: (301) 657-

9400Bethesda, MD 20815

www.meditchmurphey.com

Designing the Zero Energy House

Marcie Meditch - AIA & Mike Binder – Assoc. AIA, LEED-AP




Who We Are

► Meditch Murphey Architects is a small firm based in Chevy Chase, MD.

► Mostly single family homes but expanding into multi-family housing, small commercial and institutional projects.

► Commitment to sustainable design that is comfortable, beautiful and affordable.




What IS Zero-Energy?

► Goal : House is designed to produce as much energy as it consumes on yearly basis.

► The power grid is our storage system.




Our Motivation

► To prove that a zero-energy, market-viable speculative house is possible.

• Cost competitive

• Beautiful

• Sustainable

► Because American energy independence is important.

► Because a healthy natural environment is important

Bethesda Zero

Chesapeake Zero




► Highly Insulated, Tightly Sealed Envelope

► High Efficiency Mechanical System

► High-Efficiency Appliances

► Taking Advantage of Free Energy

► Solar Power – Heat and Electricity

How to achieveZero-Energy




Beyond Zero-Energy

► Water efficiency

► Sustainable materials

► LEED-H Platinum Rating

• Leadership in Energy & Environmental Design for Homes.

• Levels (high to low) Platinum Gold Silver Certified

• EnergyStar Home

► Public Outreach and Education

► Market Viability




Design Process

► Integrated Design Team• Architect• Owner• Builder• Mechanical Electrical and

Plumbing Engineer (MEP)• Structural Engineer• Civil Engineer• Landscape Architect• LEED Consultant/Green-

Rater

► Sustainability from Day-1

► Staying focused on goals

► Accepting trade-offs• Energy vs. water vs.

materials• Sustainability vs. cost• Up-front vs. recurring costs

► Exploit synergy, know when to stop




The Architectural Design

► Comfort

► Aesthetics

► Efficiency

► Sustainability

► Cost

► Context

Kitchen viewed from Dining RoomFront of house with entry and pergola.First floor

Second floorLiving room & Dining room viewed from Kitchen

Solar array




Site Selection

► Infill vs. Virgin Territory

► Public Amenities

• Transportation

29

T2

3232

1/4 mi1/4 mi 1/2 mi1/2 mi




Site Selection



• Transportation

• Community Services

Community Pool

Bannockburn Elementary School

Community Clubhouse

Walt Whitman Senior High School

Glen Echo Park




Site Selection



• Transportation


• Greenspace

PARK

CLUBHOUSE




Site Selection



• Transportation

• Greenspace


► House Orientation for optimum solar income:

• Passive solar design

• Solar hot-water and Electricity.




Building Demolition & Construction Waste

► Neighbors offered materials from existing house

• Cabinets,

• Flooring

• Fixtures

• Windows & Doors

► Contractor salvaged all usable materials for reuse/recycling.

► Very little waste sent to landfill.

► Framing lumber being ordered to minimize waste.

► All waste is being tracked.

► Waste materials will be sorted and recycled to greatest degree possible.




Envelope – Insulation

► The cheapest energy to buy is the energy you don’t use.

► Continuous Air-Barrier, sealed at all openings and edges.

► Basement walls : R-20 (R-13 by code)

► Slab : R-10

► Wall : R-33 (R-19 by code)

► Roof : R-50 (R-30 by code)

► High-reflectivity roofing to reduce heat island




Envelope – Windows

► Windows/Doors

• U-factor = 0.32 (R3)

• Solar Heat Gain Coeff. (SHGC) = 0.28





► Windows/Doors

• U-factor = 0.32 (R3)

• Solar Heat Gain Coeff. (SHGC) = 0.28

► Limit East and West facing Glass

• At least 50% more glass on North and South than on East and West.

► Shade South-facing Windows and Doors

• exclude heat in summer, admit it in winter

SOUTH





EAST

WEST

NORTH

SOUTH

Limit East and West facing GlassAt least 50% more glass on North and South than on East and West.




Envelope – Sustainable Materials

► Framing : FSC if you can afford it… we couldn’t.

► Soy-based foam insulation

► Local or recycled gypsum

► Local, recycled, reclaimed or FSC siding.

► Reclaimed buildings

► Low VOC sealants

FOREST STEWARDSHIP COUNCIL Certified




Passive Mechanical Systems –

Nature’s Services

► Natural ventilation during swing months

• Operable windows

• Cross-ventilation

• Timed or Humidistat controlled fans in bathrooms.

► Awnings and trees reduce cooling requirements in summer.

► South orientation allows for some passive heating in winter.




Active Mechanical Systems –

Heating & Cooling

► Geothermal – Ground Source Heat Pump

► Energy Recover Ventilator

► Sealed duct work, all INSIDE the Envelope.

► Mechanical Ventilation – “seal tight, ventilate right” – 0.35 air changes per hour.

► House zoned to allow upstairs and basement to be ‘shut down’ when not in use. Master bedroom is also a separate zone for day-night differential control.

BASEMENT

ZONE 1

ZONE 2

ZONE 3

ZONE 4




Appliances

► EnergyStar Appliances

• Refrigerator

• Convection ovens

• Induction cooktop

• Dishwasher

• Clothes Washer (no dryer is energy efficient – consider clothesline instead)

► Compact Fluorescent (CFL) and LED Lights, EnergyStar Ceiling Fans.

► Gas fireplace w/ Electronic Ignition




Power Generation

► 9.5 kW Photovoltaic array • Goal: 100% of annual

electricity needs • 49 panels on the roof• Two inverters in the

basement• Grid tied : power grid is our

storage system

► Solar Hot Water system• Goal: 85% of hot water

needs• 2 flat panel panels on roof

(tubes another option)• 120 gallon pre-heat tank in

basement




Energy Balance

► Zero was our goal, but don’t have to go that far to save money and the environment.

► High efficiency envelope, HVAC and appliances cuts demand to manageable level.

► Cut usage first before buying more PV panels.

► Knowing when to stop – the better it is, the harder it is to improve.




Water Efficiency

► No irrigation system required. Plants are drought tolerant.

► Low-flow fixtures• 1.75 gpm shower head• 1.5 gpm lavatory faucets• 1.1 gallon per flush

toilets• Clothes Washer – Water

Factor ≤ 5.5

► Recirculation pump – water recirculated to tank until desired temperature is reached.

► Fixture-by-fixture graywater reuse – had to delete because of county permit trouble.

► Still considering rainwater harvesting AQUS system from AquaPro Solutions

s s sMotion Sensor

Hot water heater

Motion Sensor Motion Sensor

warm water recirculates in cold water line

RECIRCULATION PUMP

sink

sink

tub

shower




Finish Materials – Sustainability

► LEED Recognizes following materials as ‘environmentally preferred’:

• FSC Certified (Forrest Stewardship Council)

• Recycled (including rubber)

• Reclaimed• Local• Rapidly Renewable

(bamboo, linoleum)

► Low VOC (Volatile Organic Compounds).

► No urea-formaldehyde

► No exotic woods

► Durability – more about how and where materials are installed than materials themselves. Ray Amos – New Oxford Studios




Finish Materials on Our project

► No added urea-formaldehyde in anything

► Low VOC paints, sealants, adhesives.

► Hard-floors instead of Carpet

• FSC / reclaimed / local Hardwoods

• Engineered wood• Linoleum• Rubber

► Cabinets• FSC / reclaimed / local

woods

► NOT planned• FSC framing or trim • Window / Door framing –

hard to get.




Landscaping

► Keeping rainwater on-site

• Nearly 100% Pervious surfaces.

• Light colored surfaces to reduce heat island effect

• Rainwater harvesting (still being considered)

• Bioswales (not planned)• Green Roof (planned as an

OPTION)




Landscaping

► Shading the House (but not the panels)

► Saving potable water

• 100% Drought tolerant

• High-efficiency irrigation system (we need NO irrigation system)

► Native Species Only

► Protecting house

• No materials that attract termites within 2 ft. of house.

► Minimize site disturbance, add plantings to eliminate erosion.




Cost Advantages of Green Building

► Basically prepaying your energy bills for next 25 years.

• It’s (relatively) inflation-proof

• It’s deductible

► Comfort• Sustainable materials

are healthier for you and your family to live with.

• Tight, energy-efficient construction is more comfortable to live in (when properly designed).

► Grants and Tax Rebates• Federal• State• Local

► Cooperatives offer additional discounts.

http://www.dsireusa.org/




ROI on Green Building

► One Example

• $11,900 added cost

• $1000 added mortgage payments per YEAR

• $1,900 utility savings per year

• About $900 / year ROI

Near net-zero house in Massachusetts courtesy Steven Winters Associates




LEED-H

► Administered by U.S. Green Building Council (USGBC).

► Considered by many to be the de-facto standard for green home construction

► LEED-H is administered by approved network of Green Raters.

► Other standards exist

• EnergyStar (U.S. EPA)

• NAHB (National Association of Home Builders).

• Others?




LEED-H – Cost trade-offs

► Bragging rights

► Marketing tool for sale / resale

► Can definitely add to cost, may save money in long run. Really depends.

► Point system seems odd at times:

• Skewed in places : same points for shoe rack as for all FSC framing.

• No-irrigation landscape earns less points than high-efficiency irrigation system.

• Tends to suppress innovation.

• Zero-energy design not rewarded.




LEED-H – Our score

► Going for PLATINUM (102.5 points), might settle for GOLD.




Summary – the Fundamentals

► Site selection

► Energy efficiency

► Water efficiency

► Sustainable materials• Recycled• Reclaimed• Local• Certified

► Demolition and construction waste management.




Summary

► Have to decide what’s important to you. Setting priorities and limits.

► Synergy and Holistic design – Look for opportunities to achieve multiple goals with one solution.

► Explore LEED but be open to other options too.

► You want something that you will love and which will enrich the community. This is why Architects are especially important.

► The Zero Energy House Project embodies all these principles and is at frontier of market-rate speculative house construction. Webcam image

April 13, 2009

8:21 AM

Making Progress




Shameless Plug

► For more information, visit our website at www.meditchmurphy.com

► If you are looking for a good and green architect for

• New construction

• Additions

• Renovations

CALL Meditch Murphey Architects

@ (301) 657-9400.

Meditch Murphey Architects 6900 Wisconsin Ave – Suite 500phone: (301) 657-9400 Bethesda, MD 20815...

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