RDSAP 2009Getting to grips with

the changes

Mike ToftsClient Services

Welcome & Introductions• Welcome• About National Energy Services• Attendees?

Purpose• Provide details of the changes to RDSAP2009• Provide guidance on dealing with the changes• Identify how new assessments will be affected

by the changes• Demonstrate with worked examples

Agenda• Background• Changes to SAP2009• Changes in the RDSAP Methodology

– Construction data• Break• Changes in the RDSAP Methodology

– Building services• Changes in the content and format of the EPC• Q & A , discussion

RDSAP 2009• From 17th April 2011 the version of RDSAP

used to produce EPCs for existing dwelling is changing

• RDSAP 2009 introduces some new data items and uses the recent SAP 2009 methodology for the calculation

• Is referred to as RDSAP2009 as it is based on the SAP2009 methodology

Why change RDSAP?• Incorporate changes introduced in the

main SAP methodology• Include changes through feedback from

assessors and users that have been approved by CLG (Conventions Group)

• Incorporate new data collection items to make the assessment more accurate, i.e. ongoing technical development of the RDSAP methodology

SAP Methodology Changes

SAP Changes affecting RDSAP• Calculation basis changed• Heating energy calculation• Multiple heating systems• Thermal mass parameter• Hot water usage• Heating system data enhancements• Fuel Prices• CO2 emissions factors

SAP Changes not affecting RDSAP• Cooling energy included• Multiple ventilation systems• Party wall performance criteria• Thermal bridging parameters• Multiple wind turbines• Heat recovery from showers• Heat recovery from flues• Multiple ‘special features’ (Appendix Q)

SAP Calculation Basis• SAP 2009 now calculates the heating and

hot water requirement on a monthly basis rather than an annual basis as per SAP 2005 and is therefore more accurate

SAP Heating Energy• Split winter/summer boiler efficiencies -

There are different boiler efficiencies for winter and summer months

• For example a boiler with an annual efficiency of 90% has a summer efficiency of 80.8% and a winter efficiency of 90.9%

SAP Multiple Heating Systems• Two main heating systems plus secondary• Separate presentation section later

Thermal Mass Parameter• Full SAP now includes a range of variables

(low/medium/heavy) to identify thermal mass of the dwelling

• RDSAP now includes a single mid-range medium weight default value for all dwellings

• Significance of thermal mass ?

Hot Water Usage• Estimates for hot water usage are now

lower in SAP2009• Usage previously based on linear

extrapolation of persons /m2

• Revised equation now ‘plateaus’ for larger dwellings earlier

• Hot water usage will be reduced for larger dwellings

Occupancy

SAP2009

SAP2005

Heat Pump Systems• Heat pump options now incorporated in

Product Database• Separate RDSAP presentation section later

SAP 2009 – Fuel Prices• New fuel prices for SAP2009• Rolling 3 year average to bring costs ‘up to

date’• Fuel prices increased will influence, i.e

reduce SAP 2005 Ratings ?

Fuel Price Changes - ExamplesTable 12 SAP 2005 SAP2009

Standing Charge (p/day)

Unit price (p/kWh)

Standing Charge (p/day)

Unit price (p/kWh)

Variance (%)

Mains Gas 34 1.63 106 3.1 +90

Bulk LPG 62 3.71 70 5.73 +54

Heating Oil 2.17 4.06 +87

House Coal 1.91 2.97 +55

Smokeless 2.67 3.73 +40

Wood Logs 2.2 3.42 +55

Electricity 7.12 11.46 +61

Electricity Off Peak

20 7.65 / 2.94 12.82 / 4.78 +68 / +63

SAP 2009 – Fuel Prices

SAP 2009 – Fuel Prices

• Deflator removes inflationary increases• Measure of relative cost performance• Gas performance left relatively unchanged• SAP=1 and SAP=100 datums must remain

EPC Fuel Prices ?Don’t forget :-• Fuel prices for EPC running costs are not

the same as the SAP fuel costs• EPC fuel prices are the average fuel prices

over the past 6 months

SAP 2009 – CO2 Emissions

• CO2 emissions factors developed to include ‘embodied’ CO2 – will influence EI Rating, e.g. wood pellets (manufactured) have a higher emission factor than wood logs due to the energy/CO2 resulting from manufacture.

• Will affect Environmental Impact (EI) Rating produced by the EPC ?

SAP 2009 - CO2 Emission Factors Electricity + 23%Wood Pellets + 12%Dual Fuel + 10%LPG + 5%Oil / House coal + 3%Mains Gas + 2%Wood Logs - 64%Smokeless - 12%Electricity displaced - 7%from grid

SAP 2009 - CO2 Emission Factors Community Heating from :

Waste heat + 222%

Geothermal + 100%

Biomass - 48%

Waste combustion - 30%

Biogas - 28%

SAP2009 EI Rating

CO2 Emission FactorsFuel Type 2006

kg CO2/kWh2010

kg CO2/kWh% Change

Biomass 0.025 0.013 -48

Biogas 0.025 0.018 -28

Waste Heat 0.018 0.058 +222

Natural gas 0.194 0.198 +2.1

Dual fuel (Mineral + Wood) 0.187 0.206 +10.2

Lpg 0.234 0.245 +4.7

Fuel oil 0.265 0.297 +12.1

Anthracite 0.317 0.318 +0.3

Smokeless Fuel 0.392 0.344 -12.2

Coal 0.291 0.350 +20.3

Grid supplied electricity 0.422 0.517 +22.5

Grid displaced electricity 0.568 0.529 -6.9

SAP 2009 – EI Rating• Absolute values of CO2 emissions affect the

rating, rather than proportional changes• Electricity is the main ‘loser’ due to a large

absolute value and a significant change in assumed emissions

• ‘All electric’ dwellings will be affected

SAP 2009 – Net Effect• The effect on the SAP and EI ratings is quite

small in most cases, with all else being equal, the SAP and EI rating is reduced in the region of 2 - 4 points - significant ?

RDSAP 2009 Methodology

RDSAP 2009 Methodology• Construction data• Building services data• EPC content and presentation

RDSAP 2009 – Construction Data• Increase to number of extensions• Additional floor and roof types• More detail for roofs and roof rooms• Insulation options for timber framed walls

Up to Four Extensions (1)• RDSAP 2009 can now cater for up to 4

extensions / different construction standards (in addition to ‘main’)

• This should remove the need to merge extensions together in most cases

• Data collection process per extension as before

• Are 5 construction standards enough ?

Up to Four Extensions (2)• Remember, in RDSAP an extension is a part

of the dwelling with a different thermal construction standard, not necessarily an addition to the original dwelling

• You should use the extension facility wherever there is a different construction type, age or insulation level

• Previous merging rules still apply ‘to reduce to four extensions’

• Alternative Wall – remains an option

Up to Four Extensions (3)• Number of extensions present identified in General

Details as before

Up to Four Extensions (4)

Up to Four Extensions (5)• EPC performance details are now potentially

more complicated in terms of additional construction details – ‘Energy Performance Related Features’ – see EPC format later

• Therefore, in order to simplify the table :-– If any individual element type is less than 10% of

the total element type area it will not be listed– The 3 elements of any given type with the largest

area will be listed– If 2 elements of the same construction type have

the same area then the priority order for display is main, extension 1, extension 2 etc

Up to Four Extensions (6)

Up to Four Extensions (7)• Examples of real buildings• Interface demonstration

Vertical Extensions• Occasionally, dwellings are extended upwards

by the addition of another storey• Previously dealt with by ‘alternative wall’ but

this was limited to thermal performance selection ‘from main’

• RDSAP2009 now makes this modelling possible using the following references:-– Roof construction type – Same dwelling above– Floor construction type – Same dwelling below

Vertical Extension Example• Enter as a two storey dwelling• Enter the new storey at first floor level

as an extension with :-• Roof type – as standard options• Floor type – same dwelling below

• Enter the ground floor original main dwelling with:-• Roof type – same dwelling above• Floor type – as standard options

• Note when using floor type same dwelling below there must be a corresponding part of the dwelling with roof type same dwelling above

Vertical Extension Example (2)

See file ref. 67615

Floor and roof heat loss types• In addition to providing roof and floor types that cater for vertical extensions, RDSAP2009 incorporates

further types that should enable the Assessor to cope with a number of permutations that were previously only available to flats and maisonettes :-

• In particular, the semi-exposed and other dwelling options are useful for more involved geometries :-

Unusual Geometry – Example 1• House extended by the acquisition

of the adjacent ground floor flat• The main should be entered as a

house• The extension should be entered

as a single storey extension with floor type as ground floor and roof type as other dwelling above

n.b. If ‘Different dwelling’ replaced by commercial premises, still enter as other dwelling above

Unusual Geometry – Example 1

Unusual Geometry – Example 2• Some dwellings may

have other types of premises below –

• Other dwellings• Offices• Garages (including own

integral garage)• Additional RDSAP2009

options enable more effective modelling?

Example 2 – Data Entry• Split the dwelling into

Main plus Extension• To reflect floor type

appropriately• Office – semi-exposed floor

(part heated) plus adjacent wall at ground level is non heat loss wall

• Internal car park - semi-exposed floor (unheated)

• Through archway – exposed floor

Example 2 – Data Entry

Flat Roof Insulation Options• RDSAP 2009 provides additional options for the

identification of roof insulation thickness• Documentary evidence required, otherwise ‘unknown’

should be selected• Flat roof insulation options are as follows :-

• Selecting ‘unknown assumes 50mm• Remember to double thickness for modern foam etc.

Roof Rafter Insulation Options• RDSAP 2009 provides additional options for the

identification of roof insulation thickness at rafters• Documentary evidence required, otherwise ‘unknown’

should be selected• Insulation options at rafters are as follows :-

• Selecting ‘unknown assumes 50mm• Remember to double thickness for modern foam etc.

Roof Room Insulation (1)RDSAP 2009 now has 4 options for the all elements option for roof room insulation:– All elements - 50mm– All elements - 100mm– All elements - 150mm– All elements – unknown (defaults to 50mm)

• This will enable you to record more than 50mm for the walls and sloping parts of the roof room, if you have visual or documentary evidence to support this

• Ceiling component insulation thickness still entered separately

Roof Room Insulation (2)

Residual loft area

Walls and sloping parts of the roof

Flat ceiling

Timber Frame Walls• Timber frame walls with retro-fit insulation (internal

or external) can now be recorded• Can be applied to any age band• Options are –

– External– Internal– As built– Unknown

• Effect is much reduced with more recent constructions

Secondary GlazingAmendment to conventions for April :-• Input single glazing with secondary glazing as

secondary glazing• Input double glazing with secondary glazing as

newer, i.e. 2002 or later, 2003 or later or 2006 or later for E&W, Scotland and NI respectively

• Evidence of existence and ability to re-fit required and recorded

RDSAP 2009 – Construction DataInterface Demonstration

RDSAP 2009 – Construction DataPractical Task 1

Practical Task 1

Practical Task 1

Practical Task 1• Refer to the document

provided• A brief history of the

dwelling• You will need to read

through all of the details before commencing the task

• Initially, deal with strictly as presented, other discussions to follow

Practical Task 1 – Further Issues ?• Wall between house and garage• Original build vs extension 2 ?• Utility room – extension ?• Bedroom area above unheated garage• Additional alternative walls ?

RDSAP 2009 – Building Services

RDSAP 2009 – Building services• More options for and the inclusion of heat

pumps and micro-chp in Product Database• More options for primary and secondary

heating• Improved ‘hot water only’ options• Additional controls for community heating• Additional fuels available• Alternative data entry option for

photovoltaic (PV) systems• Minor modification to lighting data

RDSAP 2009 – Building ServicesHeat Pumps & Micro CHP

Heat Pumps• Take heat from a low temperature source

and upgrade it to a higher temperature• Most commonly run on electricity but gas-

fired heat pumps are also available• Can be used in community heating

schemes as well as individual systems

Heat Pumps - Schematic

RDSAP2009 Heat Pump Options• Two heater type options :-

– Heat pump – wet system– Heat pump – warm air

• Four system options :-– Ground to water / air– Ground to water / air with auxiliary heater– Water to water / air– Air to water / air

• Two emitter options - radiators or underfloor

RDSAP 2009 Heat Pumps

Heat Pump Default Efficiencies

Type of heat pump Default efficiency

Ground source 320%

Ground source with auxiliary heater 300%

Water source 300%

Air source 250%

Ground or water source – gas fired 120%

Air source – gas fired 110%

• If Product Database is not used :-

BEDF to PCDF• The Boiler Efficiency Database File (BEDF) AKA SEDBUK,

is now referred to as the Product Database or PCDF (Product Characteristics Database File)

• All familiar gas and oil boiler options are retained but the database has been expanded to include :-– Heat pumps– Micro-chp

• Always use the PCDF whenever possible, SAP defaults are worst case assumptions

Heat Pump Database• Appliance specific efficiencies should be used

where the system specified is in the database• 32 systems currently included in the database

– 17 air source heat pump– 12 ground source heat pump– 3 exhaust air heat pumps

• Also need to specify emitter type – radiators, under floor etc., for efficiency adjustment

Heat Pump Database

Micro chp - Schematic

Micro chp -Images

RDSAP2009 Micro CHP Options• New option for RDSAP2009• One system option within the Product Database ,

no RDSAP default option• Select emitter type as per heat pump options

Plant Size Ratio - PSR• For heat pumps and micro-CHP systems to

function effectively they must be sized correctly for the dwelling. The sizing of the system in relation to the dwelling heating demand is known as the Plant Size Ratio - PSR

• RDSAP2009 automatically checks the PSR of the system you select from the PCDF against the calculated requirement for the dwelling and if incorrectly sized you will get a message “PSR too high or too low “

Plant Size Ratio – PSR (2)• If you receive the message “PSR too large or too low “, then

enter the heat pump as a SAP default heat pump in the usual way by selecting the system from the heating page :-

• For micro CHP – select condensing boiler• Make a note in your site notes that you have been unable

to select the system from the PCDF

Plant Size Ratio – PSR (3)

• RDSAP will identify any requirement for further heating based on the Plant Size Ratio

• Any space heating requirement not met by the Main System is assumed to be supplied by a secondary heating system (or a second main system)

• If neither is present then the software will assume portable electric heating will make up the remainder

RDSAP 2009 – Two Main Heating Systems

Two Main Heating Systems• RDSAP2009 allows you to identify 2 main/primary heating

systems when two main systems heat different parts of the property

• In addition to a (single) secondary heating system• This would cater for :-

– A large house served by two separate boiler systems – extensions ?– A house with a boiler and storage heaters for space heating– A main space heating system plus a water heating boiler that can

be identified on the PCDF

• In order to use this facility you will need to know the fraction of heat supplied by each system– This can be based upon the % floor areas served

Two Main Heating Systems

Multiple Heating - Conventions1. A Main System is generally a central heating system i.e. a

centralised heat generator providing heat to several rooms via a distribution system but can also be electric storage heaters with on peak top up

2. If Main System 1 heats all habitable rooms, there is no Main System 2 unless it provides DHW only

3. Main systems 1 and 2 cannot be room heaters unless the dwelling is only heated by room heaters

4. If Main System 1 is community heating there is no Main System 2

5. A Main system Heat pump and micro-CHP systems (from database) can only be entered as Main Heating System 1

6. Main Heating System 1 is always the system that heats the living room, unless HP or micro-CHP, in which case it may be Heating System 2

Multiple Heating - Conventions7. Two Main heating systems will be allocated in

accordance with the % heated floor area served8. If both Main Heating Systems are solid fuel, the

fraction of heat from each must be entered as 50%9. Where 2 Main Systems serve the same heating circuit,

assume a 50/50 split unless documentary evidence is available to the contrary

10. If you have one option for Main 1 but 2 options for secondary then decide which secondary as normal – Main 2 is not used

11. If 2 room heater types present, then select as normal but enter as Main 1 and Main 2

12. Where there are 2 main heating systems and a heating recommendation is made, include Addendum 9

Multiple Heating - Recommendations• Where two Main heating systems use the same

fuel, any heating recommendation applies to both systems (RDSAP addresses separately)

• If the systems use different fuels, the recommendation applies to Main System 1 only

• Any heating controls recommendation will apply to Main System 1 only

• Include Addenda 9 for 2 Main Heating Systems :-

Secondary Heating Systems ?• No change to the secondary heating

selection process / assumed default of portable electric heating from RDSAP 2005

• However, new single secondary heating system option :-– Bioethanol room heater !

Display 2 main + sec

RDSAP 2009 – Water Heating Options

Water Heating Options• New water heating options for

RDSAP2009 :-– Boilers/Circulators for hot water only– Range cookers for hot water only– Community heating for hot water only• Boilers/Circulators for hot water only – is an

additional system type option for regular water heating, the other 2 options are new water heating types

Water Heating Options• In EPC online, you will now need to select the water

type before selecting the water system:-

Water Heating Types

• Regular – all the current water heating systems and the new RDSAP2009 DHW-only boiler/circulators

• Range cookers – DHW only range cookers• Community heating - DHW only community

heating• Previous ‘workarounds’ are now redundant

Regular Water Heating Options• SCREEN SHOT

Range Cooker Hot Water Options• SCREENSHOT

Reduced list in place

Hot Water Only Community Scheme• Now 3 options relating to the type of community system:-

– Community boilers– Community CHP– Community heat pump (electricity is the only fuel)

• If you cannot ascertain the system select community boilers

• If you cannot ascertain the fuel select mains gas

Display water etc.

Community Heating Changes• Community Heating Fuels

– The full range of SAP 2009 community heating fuels are now available for RDSAP 2009

– Note introduction of Geothermal heat source and application !

• Community Heating Controls – full SAP range available• Additional control types -

– Flat rate charging and TRVs– Charging system linked to use and room thermostat only– Charging system linked to use, programmer and room thermostat– Charging system linked to use and TRVs– Note flat rate vs charging system

Community Heating Fuels• B30D – a mix of 30% biodiesel from cooking oil and 70%

fuel oil• Waste combustion - also known as Municipal Waste

Incineration there are several system using waste as fuel in the UK

• Biomass –any wood based fuel (logs/chips/pellets)• Biogas – using the gas produced from sewerage or land fill• Waste heat from power stations – capturing and utilising

the heat produced from power stations

RDSAP 2009 - New Fuels• As well as the new community heating fuels, there are 2

new fuels for non-community heating systems:– LPG subject to special condition 18 (Documentary evidence)

This is specific to a four towns; Colden, Llanfyllin, Llanwrtyd and Stornoway, where there is an independent LPG network and the LPG is charged at mains gas prices. This will not have an affect on the EI rating but will dramatically increase the SAP rating – why ?

– B30KThis is a biofuel, with 30% biodiesel from cooking oil and 70% kerosene.

RDSAP2009 - Photovoltaics• If PV is present at a property you can now enter the kWp rather than the % of roof area• Documentary evidence is required – look for a schematic drawing, possible adjacent to

electricity meter or consumer unit• Schematic should provide the following :-

– Peak power – kWp– Estimate of pitch angle (default to 30 deg)– Overshading (if in doubt select modest)

Photovoltaics• If PV is present at a property you can now

enter the kWp rather than the % of roof area• Documentary evidence is required

RDSAP2009 Lighting• Identify the total number of fittings and the number of LEL

fittings rather than the % of LEL• The number of non-LEL fittings can then be used to calculate

an appropriate indicative cost for the lighting recommendation

Screen shot

Cooling Systems• Note the tick box is only for fixed cooling systems only.

Reversible heat pumps are entered as part of the heating system data entry.

• Cooling system produces a general advisory statement on the EPC

RDSAP 2009 – Building ServicesInterface Demonstration

Renewable Heat Incentive (RHI)• Government run scheme to financially support the introduction of

renewable technologies, similar to the Feed in Tariff (FIT) that supports PV installations

• Recipients of the RHI will receive a payment for each kWh of space heating and/or water heating produced from renewable sources such as :-– Heat pumps, Biomass boilers (not stoves), solar thermal & Bio-fuel

boilers • The deemed heat and water requirement of the dwelling is

calculated using RDSAP methodology but adjusted for the region• The tariff paid depends on the renewable source• There are limitations to when and how they must be installed• For more information go to www.decc.gov.uk/rhi

Renewable Heat Incentive (RHI)• RDSAP2009 now includes an assessment of the heat

demand of the dwelling that would qualify for the RHI• Calculation adjusts heat demand in accordance with

regional temperature demands (like NHER) and applies the installation of basic energy efficiency measures to finalise the RHI figure.

• Payments in the region of XXp/kWh for a time period of 20 years

RDSAP 2009 – Changes to the EPC Presentation and Format

RDSAP2009 – EPC Changes• Revised page order• New renewable heat incentive calculation• Revised presentation to PRF table• Additional bullet points for action - “What

can I do today”• Indicative installation costs incorporated

EPC Format• The front page now highlights the possible savings (lower

and higher cost measures only)

EPC Format• Recommendations now on page 3 and include indicative

installation costs• Indicative costs will be updated regularly via the PCDF

(formally BEDF)• Indicative costs for loft and wall insulation will vary according

to the size of the loft / wall• Indicative costs for lighting will vary according to the number

of fittings

Up to Four Extensions (5)• EPC performance details are now potentially

more complicated in terms of additional construction details – ‘Energy Performance Related Features’ – see EPC format later

• Therefore, in order to simplify the table :-– If any individual element type is less than 10% of

the total element type area it will not be listed– The 3 elements of any given type with the largest

area will be listed– If 2 elements of the same construction type have

the same area then the priority order for display is main, extension 1, extension 2 etc

EPC Format• Performance related features table now uses stars to rate the

energy efficiency• Only the largest 3 walls/floors/roofs will be displayed

EPC Format• Renewable heat incentive assessment (regional)• Displays the heating and DHW requirement• If there is no cavity wall insulation or loft insulation this is applied

and the heat/DHW requirement is re-calculated

Revised Data Collection Forms• Revised set of data collection forms to be issued shortly• Forms P1 & P2 edited with the main changes• New Form P3 for data entry for extensions 3 and 4• Two Main Heating Systems will require an ‘H’ form for each• Available through NES one Useful documents• Assessor forms will require similar annotation

RDSAP 2009Getting to grips withthe changes – Q & A

Mike ToftsClient Services