RdSAP principles

Concepts of RdSAP

• Dwelling Types

• Building Parts

• Dimensions

• Age Bands

• Habitable Rooms

Dwelling Types

Dwelling Type•House•Bungalow•Flat•Maisonette•Park Home

Built Form•Detached•Semi-detached•Mid-terrace•End-terrace•Enclosed mid-terrace•Enclosed end-terrace

Building Parts

For simplicity of data entry the dwelling is divided into ‘main dwelling’ and ‘extensions’

Extensions may not be extensions in the conventional sense of the word, so we describe them as ‘parts’

Building Parts

A building part:•has only one roof type•has only one floor type•was entirely built in one age band

Building Parts

Building Parts

100mm insulation

50mm insulation

suspended floorsuspended floor

Age band A (pre 1900)

Age band A (pre 1900)

2 building parts (main + ext 1)

Building Parts

100mm insulation

100mm insulation

suspended floorsuspended floor

Age band A (pre 1900)

Age band C (1930-1949)

2 building parts (main + ext 1)

Building Parts

100mm insulation

100mm insulation

suspended floorsolid floor

Age band A (pre 1900)

2 building parts (main + ext 1)

Age band A (pre 1900)

Building Parts

100mm insulation

100mm insulation

suspended floorsuspended floor

Age band A (pre 1900)

Age band A (pre 1900)

1 building parts (main only)

Dimensions

Once the dwelling is divided into parts, each storey of each part is defined by 4 dimensions each

Dimensions

• Internal or external (but not both!)

• 4 components:•Area•Storey Height•Exposed Perimeter•Party Wall

Dimensions:‘Heated envelope’

Porches•Include if heated by fixed heating devices•Exclude if unheated and

• external (i.e. protruding from external wall) or thermally separated from dwelling

Dimensions:‘Heated envelope’

Conservatories•Include unless separated from dwelling by wall with exterior grade doors and windows•Exclude if separated as above

Dimensions:‘Heated envelope’

Store / utility rooms•Exclude if only accessible from outside of the dwelling•Include if directly accessible from the occupied part of the dwelling

Age Bands

Age bands are key to RdSAP, as they are the basis of a variety of assumptions about the performance of the dwelling

Age Bands

• Record per part

• Build NOT refurb date (unless uninhabitable before refurb)

• (Slightly different in devolved nations)

England & Wales

Scotland Northern Ireland

Park Homes

Pre 1900 before 1900 before 1900 n/a

1900 - 1929 1900 - 1929 1900 - 1929 n/a

1930 - 1949 1930 - 1949 1930 - 1949 n/a

1950 - 1966 1950 - 1964 1950 - 1973 n/a

1967 - 1975 1965 - 1975 1974 - 1977 n/a

1976 - 1982 1976 - 1983 1978 - 1985 Before 1983

1983 - 1990 1984 - 1990 1986 - 1991 1983 - 1995

1991 - 1995 1992 - 1998 1992 - 1999 n/a

1996 - 2002 1999 - 2002 2000 - 2006 1996 - 2005

2003 - 2006 2003 - 2007 n/a n/a

2007 – 2011 2008 - 2011 2007 – 2013 2006 onwards

2012 onwards 2012 onwards 2014 onwards n/a

A before 1900

B 1900 - 1929

C 1930 - 1949

D 1950 - 1966

E 1967 - 1975

F 1976 - 1982

G 1983 - 1990

H 1991 - 1995

I 1996 - 2002

J 2003 - 2006

K 2007 - 2011

L 2012 onwards

Age Bands

Critical – software makes assumptions about thermal values based on age

Seek information from:•Occupier / agent•Documentary evidence•Property style•Building regs-related features

Habitable rooms

Habitable rooms are another peculiar RdSAP concept, and are used to make assumptions about the proportion of the home is that is a ‘living’ area, which informs how it is heated

Habitable rooms

RdSAP needs a simple count

Always included in the count:•Living rooms•Sitting rooms•Dining rooms•Studies•Bedrooms

Habitable rooms

Always excluded from the count:•Utility rooms•Bathrooms / WCs•Cloakrooms•Halls / Landings / Stairways•En-suite

Habitable rooms:kitchen

Include if there is space for a table and 4 chairs

Otherwise exclude

Habitable rooms:divisions

• Open plan areas• one room

• Rooms divided by a doorway where door temporarily removed - architrave present and hinge holes not filled in• two rooms

Heated habitable rooms

RdSAP needs a second simple count

•A heated habitable room is a habitable room with a fixed heat emitter

Construction and insulation

How to enter walls, floors, roofs

Wall construction

Construction types:•Cavity •Solid brick•Timber framed•System built•Sandstone•Granite or whinstone•Cob•Park home wall (park home only)

Wall insulation

Insulation types:•As built•Unknown•Internal•External•Filled cavity•Filled cavity + internal•Filled cavity + external

Wall insulation

• Wall and insulation thickness must also be measured

• Around window reveals usually best place

Roof construction

• Flat• Pitched, access• Pitched, no

access to loft• Pitched (thatch)• Other dwelling

above• Same dwelling

above• Pitched, sloping

Roof insulation

Position of insulation:•Rafters•Joists•Unknown•None•Flat roof insulation•Sloping ceiling insulation

Insulation thickness also recorded

Floor construction

• Suspended timber• Suspended-not timber• Solid• Separate entries required for main

part and any extensions

Floor insulation

• Unknown• As-built• Retro-fitted

• Insulation thickness if known

RdSAP Space Heating

How to enter details of the heating and hot water system

• RdSAP allows 2 main and 1 secondary heating system to be entered, if required

• Main Heating 1 is the one which heats living area

Main Heating Systems

Most common are:•Boiler and radiators•Electric storage heaters

Boilers• Typically a central boiler

and a circuit of pipe work distributing hot water to a number of radiators

• Can be gas, oil , LPG or biomass fuelled

• Several types with widely differing efficiencies

• ‘Wet’ underfloor heating becoming more common

Room Heaters

• Gas fires• Open fires• Closed fires (stoves)

• Usually secondary heating systems

Boiler Type

• Regular boiler• Combination boiler• Condensing regular boiler• Condensing combi boiler• CPSU• Back boiler• Range cooker boiler• Micro-CHP

Flue Type combinations

• Open flue• Open flue-fan

assisted

• Balanced flue• Fan assisted room

sealed

Central Heating Pump Age

• Unknown in most cases

• If known it can be entered into RdSAP

• Post 2012 notably better

Main Heating Controls

• Room thermostats• Programmer• TRVs• Time and temperature zone

control• Weather compensator• Boiler energy manager

Types of Secondary Heating – gas fires

Rooms in Roof

A special case and needs some description

Types

• A house designed for occupation of the roof space such as a chalet bungalow, usually built with dormer or roof light windows

• A conversion of what would normally be a loft space, above the main part of the dwelling, or above any extensions.

To be included in the RdSAP assessment: •It must be accessed via a fixed staircase•The height of the common wall must be less than 1.8m for at least 50% of common wall (excluding gable ends and party walls)

RdSAP details

In this section we will cover the details of recording the various energy-related property features in RdSAP

Terrain Type

• Urban• Suburban• Rural

Used to determine ventilation

Windows / Glazing

Key data items:•Total glazed area•Proportion of multiple-glazed area•Multiple-glazing type

Total Glazed Area

• Normal or typical• More than typical• Less than typical

• Much more than typical• Much less than typical• Sun rooms (next slide)

Extended Glazing and Sunrooms

• RdSAP definition of a conservatory: a structure with at least 75% its roof and at least 50% of its walls glazed

• Sunrooms can be entered in the extended glazing facility

Doors

• Total number of external doors includes doors to unheated corridors and any doors within the heat loss perimeter

• Double door = 2 doors• Glass patio door = window• Documentary evidence of

insulated doors required

Draughtproofing

• Proportion of draughtproofed windows and doors is entered as a percentage

• Assumptions can be made based on window type if draughtproofing cannot be determined

Open fireplaces

• Number of open fireplaces within property recorded

• Conventions apply

Low Energy Lighting

Need to record:•Total number of fixed light fittings •Total number of fixed low energy lighting fitted outlets

Only fixed lighting is assessedLED and CFL are low energy‘Low energy halogens’ are not

Ventilation Method

• Natural ventilation• Mechanical, supply and

extract*• Mechanical, extract only*

*whole house systems, NOT single room extract fansPresence of air conditioning can also be recorded by ticking a box

Electricity Meters

Meter type must be recorded•Single rate meter•Mechanical dual rate meter (often ‘white meter’)•Digital dual rate meter•Other tariffs (18/24h)

•Smart meters not yet