main heating: pre1998 ducted warm air system main heating fuel: mains gas main heating SAP efficiency: 70.0% main heating controls: programmer

Transcription

1 Archetype: Archetype Description: , semi / end terraced dwelling, timber frame walls, oil / gas / electric warm air heating, E This archetype represents 823 dwellings, which accounts for approximately 0.21% of the target dwelling stock property type: semi detached bungalow age: built c.1975 number of storeys: 1 number of habitable rooms: 4 extensions: none number of heated habitable rooms: 4 rooms in the roof: none total floor area: 62m 2 internal heat loss floor area: 62m 2 floor construction: suspended timber, as built U-value: 0.63 gross heat loss wall area: 52m 2 wall construction: timber frame wall, as built U-value: 0.8 heat loss roof area: 62m 2 roof construction: pitched, 100mm insulation U-value: 0.4 glazed area: 15.01m 2 glazing type: 100% wood / upvc double glazing, pre2003 U-value: 2.8 main heating: pre1998 ducted warm air system main heating fuel: mains gas main heating efficiency: 70.0% main heating controls: programmer secondary heating: none secondary heating fuel: n/a secondary heating efficiency: n/a hot water provision: single immersion hot water cylinder: yes cylinder size: 120 litres cylinder insulation: 25mm spray foam cylinder thermostat: yes chimneys: 0 electricty meter: single flues: 0 gas meter: yes extract fans: 1 draught lobby: no percentage of low energy lighting: 90% draughtproofing: 100% windows 0% doors EPC Band E Environmental Impact Band: E EPC Score 53 Environmental Impact Score: 52 These characteristics were modelled in 2012 to create the base case dwelling for this archetype. A number of single improvements were modelled against the base case dwelling to assess their impact on the EPC band, the score, the Environmental Impact band, and the Environmental Impact score, as well as their impact on the -calculated fuel costs, CO2 emissions and energy consumption. These results are set out in Table 1. Page 1 of 5

2 Table 1: Modelled Single Improvements: EPC Band, Score, Environmental Impact Band, Environmental Impact Score, Annual Fuel Costs, CO2 emissions, and Delivered Energy Consumption (ordered by impact on the score (lowest to highest)) Annual Fuel Costs: per year CO2 Emissions: kg of CO2 per year Delivered Energy Consumption: kwh per year code Improvement Description EPC EI EIs MH SecH HW L ren tot MH SecH HW L ren tot MH SecH HW L ren tot Base as existing E 53 E M33 low energy lighting 100% E 53 E M12 draughtproof windows and doors E 53 E M10 insulated external doors E 54 E M11 hot water tank jacket 80mm E 54 E M9 triple glazing to 1.4 E 54 E M24 room thermostat E 54 E M31 2m diameter wind turbine on roof E 54 E M5 solid wall insulation D 55 E M1 loft insulation, including top up D 55 E M6 floor insulation D 56 D M14 replace gas boiler with condensing boiler 88% D 56 D M32 5m wind turbine on stand-alone mast D 64 D EPC = EPC band / = 2012 score / EI = Environmental Impact band / EIs = Environmental Impact score MH = main heating / SecH secondary heating / HW = hot water / L = lighting and other costs (e.g. fans and pumps) / ren = impact of renewable generation / tot = total of category The starting point for this dwelling (i.e. as existing) is a Band E score of 53, that is, 2 points below Band D. For this dwelling, 12 improvement measures were assessed. Those that were not assessed, and the reasons, are set out in Table 2. Table 1 above is ordered in terms of the smallest impact on the increase in the score to the highest. Two measures (i.e. M12 - draughtproof windows and doors; and M33 - low energy lighting) do not have an impact on the score. While they do improve the dwelling's overall energy efficiency, the improvements are not sufficient in themselves to increase the score by 1 full point. Five measures on their own (highlighted in yellow in Table 1) would raise the rating into the Band D category; none are mutually exclusive. None of the measures assessed on their own raised the rating here into Band C or higher. Page 2 of 5

3 Table 2: Reasons for Measures Not Assessed in this Property code Improvement Description Improvement Modelled? M2 flat roof insulation not applicable M3 room in the roof insulation not applicable M4 cavity wall insulation not applicable M7 double glazing to 1.8 already present M8 secondary glazing to 2.4 not recommended M13 baffle / damper to open fire not applicable M15 replace oil boiler with condensing boiler 90% not applicable M16 full gas central heating system inc controls not recommended M17 full oil central heating system inc controls not recommended M18 full biomass central heating system inc controls not recommended M19 fan electric storage heaters with auto charge control not recommended M20 quantum storage heaters not recommended M21 full electric radiator system inc controls - off peak tariff not recommended M22 air source heat pump not recommended M23 ground source heat pump not recommended M25 programmer for heating system already present M26 TRVs not applicable M27 full controls package (r/stat, programmer and TRVs) not recommended M28 Auto charge control not applicable M29 Solar thermal 4m2 not recommended M30 PV 2kWp not recommended M34 Cylinder stat for hot water cylinder already present M35 Air to Air heat pump not recommended M36 replace secondary heating with one more efficient not recommended M37 electric CPSU with raidtors and controls on E18 tariff not recommended M38 switch to E24 tariff not applicable A number of the improvement measures were not assessed with regard to this dwelling. Appendix 2 of the Final Report sets out the methodology associated with modelling the 38 improvements, including why measures were not recommended, or not applicable. Page 3 of 5

4 Table 3: Impact of Single Improvements on Annual and Lifetime Fuel Costs, CO2 emissions, Delivered Energy Consumption - ordered by Capital Costs (lowest to highest) code Improvement Description EPC Band Change in score EI Band Change in EI score /year annual reductions lifetime reductions kg CO2/year kwh/year lifetime kg CO2 kwh unit costs units capital cost net lifetime saving / capital cost M33 low energy lighting 100% E 0 E M11 hot water tank jacket 80mm E 1 E M12 draughtproof windows and doors E 0 E M24 room thermostat E 1 E M1 loft insulation, including top up D 2 E M6 floor insulation D 3 D , , M10 insulated external doors E 1 E , M14 replace gas boiler with condensing boiler 88% D 3 D , , M31 2m diameter wind turbine on roof E 1 E , , M9 triple glazing to 1.4 E 1 E , , M5 solid wall insulation D 2 E , , M32 5m wind turbine on stand-alone mast D 11 D , , nb. because of the rounding of the annual reductions to the nearest integer, some of the lifetime reductions may not equal a measure's annual reduction multiplied by its respective lifetime # - because this measure has no impact on the -calculated fuel bill no payback period can be calculated. payback Table 3 sets out the resultant EPC and Environmental Impact (EI) banding for each of the individual improvement measures assessed for this dwelling, along with the changes in the respective and EI scores. It then displays the impact on the respective -calculated annual fuel bill, CO2 emissions and energy consumption for the dwelling (the pink columns in Table 3 above). Multipling the annual change in the calculated fuel costs, CO2 emissions, and energy consumption for this property, by the respective lifetime of each of the measures assessed, produces the lifetime change for each measure (see the blue columns in Table 3 above). This allows us to compare the capital costs against both the cost of the saving on the fuel bill on an annual basis (i.e. the payback), and over the lifetime of the measure (i.e. the net lifetime saving / capital cost). The net lifetime saving / capital cost subtracts the capital cost of the measure from the calculated lifetime reduction. In this column, a value greater than 0 here means the calculated lifetime fuel bill savings are greater than the capital cost of installing the measure. Where the net lifetime saving is a negative number, that is, it has a cost effectiveness of less than 0 (and highlighted in orange in Table 3), the measure will not return the cost of the original investment through savings in the fuel bills alone. Table 3 is ordered from the lowest capital cost for the improvement measure assessed to the highest. The capital costs of the individual measures ranged from 5 for one low energy light bulb, up to 20,000 for the stand-alone wind turbine. A low capital cost does not necessarily equate to a good return on an investment or short payback period; similarly, a high capital cost does not necessarily mean a poor return on the cost of the investment or a long payback. In terms of cost effectiveness, the measure with the shortest payback for this archetype is adding an insulating jacket to the hot water cylinder, with a payback of 0.7 years. Fitting the hot water tank jacket also provides the largest lifetime return on the cost of the improvement, with a return of for every pound invested over the lifetime of the measure. Seven of the measures have a cost effectiveness of less than 0 (highlighted in orange in Table 3) and will not return the cost of the original investment through savings in the fuel bills alone. However, the eligibility for other incentive schemes (e.g. Feed in Tariffs for installing wind turbines) are likely to have a significant impact on the financial return associated with these measures. The financial benefits associated with these incentive schemes are not included in the calculations here, because of their constantly changing returns. Page 4 of 5

5 From the characteristics of this archetype, the starting point for this dwelling was assessed to be a Rd 2012 Band E score of 53. Only one package was assessed for this archetype: the cheapest package of measures to raise the score so that it achieved a Band D score of at least 55. Table 4a: Cheapest Package of improvement Measures to Increase the EPC Band to Band D cummulative annual reductions cummulative lifetime reductions kg CO2/year kwh/year lifetime kg CO2 kwh unit costs units cummulative capital cost cummulative net lifetime saving / capital cost code Improvement Description EPC Band EI Band EI score /year Base as existing E 53 E 52 M24 room thermostat E 54 E M24+M11 + hot water tank jacket 80mm D 55 E cummulative payback While single measures were assessed that would achieve a Band D rating for this dwelling, there are cheaper alternatives. Adding a room thermostat to the heating controls and fitting an insulating jacket on the hot water cylinder was assessed as the cheapest package to move the rating for this property into Band D (see Table 4a). The total indicative cost of this package is estimated at approximately 223. Page 5 of 5