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Publication - Report

Energy Efficiency Standard for Social Housing: peer review

Published: 22 Oct 2013
Part of:
Environment and climate change
ISBN:
9781782569961

Peer review scrutinising the example dwellings in the Energy Efficiency Standard for Social Housing consultation document.

246 page PDF

3.8MB

246 page PDF

3.8MB

Contents
Energy Efficiency Standard for Social Housing: peer review
Annex H Modelling for Additional Case Studies

246 page PDF

3.8MB

Annex H Modelling for Additional Case Studies

Hard-to-Treat Case studies 1 - 2: Pre 1919 solid wall flats

Hard-to-Treat Case studies 1 - 2: Pre 1919 solid wall flats

Case study HTT-1E: Pre 1919 solid wall dwelling - ground floor (2 bed) (109m 2) , gable end
Fuel type: Electricity
Baseline annual fuel costs: £1,636
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - Internal insulation
(£5,500)
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,768 - £15,168
Annual fuel cost savings - £406 - £806
Percentage annual fuel cost savings - 25% - 49%
SAP Rating E (44) D (58) - C (72)
EI Rating F (25) F (34) - E (52)
Approximate CO 2 emissions kg/m 2/year 601 484 - 315
Percentage CO 2 improvement - 23% - 49%
Case study HTT-1G: Pre 1919 solid wall dwelling - ground floor (2 bed) (109m 2), gable end
Fuel type: Gas
Baseline annual fuel costs: £1,416
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - Internal insulation
(£5,500)
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £3,718 £6,518 £16,918
Annual fuel cost savings - £117 £539 £766
Percentage annual fuel cost savings - 8% 38% 54%
SAP Rating E (49) E (53) D (68) C (77)
EI Rating E (44) E (47) D (66) C (76)
Approximate CO 2 emissions kg/m 2/year 346 318 202 140
Percentage CO 2 improvement - 8% 41% 60%

The next two examples replicate the ground floor tenements of archetypes HTT-1E and HTT-1G, but use in-situ u-values instead of the default RdSAP u-values. They also use the actual costs for the floor and secondary glazing measures that were actually carried out on the archetype that HTT-1E and HTT-1G is based on.

The actual in-situ u-values for this archetype were 3.5 W/m 2K for the solid floor and 0.6 W/m 2K for the insulated floor. As RdSAP can only work within the range of 0.1 - 2.3 W/m 2K for a floor, 2.3 W/m 2K was selected for the actual baseline floor u-value. Compared to the default of 0.5 W/m 2K as calculated by RdSAP in the previous examples, 2.3 W/m 2K is still of poor thermal performance in comparison. The improved u-value of 0.6 W/m 2K was input for the insulated floor compared to 0.28 W/m 2K which is the default value for this floor with insulation of no specific thickness.

The single glazed windows had been tested in-situ and a u-value of 5.5 W/m 2K was measured. User defined u-values for windows can only be entered into RdSAP for multiple glazed windows. Therefore these were entered as double glazed in order to alter the u-value. However it was found that this u-value was out of range and the highest u-value accepted (5.1 W/m 2K) was selected. This closely compares to the default of 4.8 W/m 2K.

For window improvements secondary glazing with an in situ u-value of 2.3 W/m 2K was input, compared to 3.1 W/m 2K for pre-2003 double glazing and 2.0 W/m 2K for post 2003 double glazing.

The in-situ u-value of 1.4 W/m 2K for the sandstone wall was selected as compared to 2.0 W/m 2K for a sandstone wall with no unknown / default wall thickness. As there were no in situ wall insulation work carried out, this measure was kept as the default u-value of 0.6 W/m 2K.

The actual costs for floor insulation and secondary glazing were used. These costs were £9.434 for floor insulation and £5,040 for secondary glazing, compared to £1,200 and £3,700 used in HTT-1E and HTT-1G.

For these archetypes, the adjustments of the u-values make the expected thermal performance of this dwelling before and after improvements less efficient compared to the default assumptions. Similarly the costs for the measures are higher.

Case study HTT-1E: Pre 1919 solid wall dwelling - ground floor (2 bed), gable end (actual costs and u-values) (109m 2)
Fuel type: Electricity
Baseline annual fuel costs: £2,411
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - Internal insulation
(£5,500)
Floor No insulation - - Insulation
(£9,434*)
Roof - - - -
Windows 100% single glazing 100% secondary glazing (£5,040*) - -
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £6,108 - £21,042
Annual fuel cost savings - £623 - £1,447
Percentage annual fuel cost savings - 26% - 60%
SAP Rating F (23) E (39) - D (67)
EI Rating G (8) G (18) - E (45)
Approximate CO 2 emissions kg/m 2/year 902 718 - 370
Percentage CO 2 improvement - 18% - 58%
* - Actual costs of installation
Case study HTT-1G: Pre 1919 solid wall dwelling - ground floor (2 bed), gable end (actual costs and u-values) (109m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,884
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - Internal insulation
(£5,500)
Floor No insulation - - Insulation
(£9,434*)
Roof - - - -
Windows 100% single glazing 100% secondary glazing (£5,040*) - -
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls (£300) -
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £5,058 £7,858 £22,792
Annual fuel cost savings - £113 £697 £1,155
Percentage annual fuel cost savings - 6% 37% 61%
SAP Rating F (33) F (37) D (57) C (74)
EI Rating F (31) F (33) E (52) C (73)
Approximate CO 2 emissions kg/m 2/year 474 447 287 161
Percentage CO 2 improvement - 6% 40% 66%
* - Actual costs of installation
Case study HTT-2E: Pre 1919 solid wall dwelling - top floor (3 bed) (126m 2); gable end, partial flat roof
Fuel type: Electricity
Baseline annual fuel costs: £2,902
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - Internal insulation
(£5,500)
Floor - - - -
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
and flat roof insulation
(£1,175)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
100% double glazing (post 2003)
(£3,700)
-
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £1,668 £6,826 £12,326
Annual fuel cost savings - £970 £1,619 £1,940
Percentage annual fuel cost savings - 33% 56% 67%
SAP Rating G (19) E (40) D (60) C (70)
EI Rating G (5) G (19) F (37) E (50)
Approximate CO 2 emissions kg/m 2/year 949 675 437 319
Percentage CO 2 improvement - 29% 54% 66%
Case study HTT-2G: Pre 1919 solid wall dwelling - top floor (3 bed) (126m 2), gable end partial flat roof
Fuel type: Gas
Baseline annual fuel costs: £2,201
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - Internal insulation
(£5,500)
Floor - - - -
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
and flat roof insulation (£1,175)
-
Windows 100% single glazing 100% draughtproofing
(£100)
100% double glazing (post 2003) (£3,700) -
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £618 £8,576 £14,076
Annual fuel cost savings - £284 £1,287 £1,469
Percentage annual fuel cost savings - 13% 58% 67%
SAP Rating F (31) F (38) C (70) C (76)
EI Rating F (28) F (34) D (68) C (75)
Approximate CO 2 emissions kg/m 2/year 486 422 184 140
Percentage CO 2 improvement - 17% 63% 72%

Hard-to-Treat case studies 3 - 4: System built Multi-storey flats 1950-64

Hard-to-Treat case studies 3 - 4: System build Multi-storey flats 1950-64

Case study HTT-3E: System built Multi-storey flat 1950-64 - ground floor gable end (2 bed) (69m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,012
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,765 £10,265 £15,165
Annual fuel cost savings - £250 £288 £555
Percentage annual fuel cost savings - 25% 28% 55%
SAP Rating E (53) D (65) C (74) C (79)
EI Rating F (33) E (43) D (57) D (66)
Approximate CO 2 emissions kg/m 2/year 575 461 324 258
Percentage CO 2 improvement - 20% 44% 55%
Case study HTT-3G: System built Multi-storey flat 1950-64 - ground floor gable end (electric - gas community heating) (2 bed) (69m 2)
Fuel type: Electricity - Gas
Baseline annual fuel costs: £1,012
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation (£5,500) -
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Gas communal heating
(£12,209*)
- -
Heating system controls Manual charge control Flat rate charging, programmer and TRVs (included in communal heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam From communal heating with 80mm factory applied foam (included in communal heating costs) - -
Secondary space heating Electric room heater None - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £15,924 £21,424 £26,324
Annual fuel cost savings - £350 £486 £563
Percentage annual fuel cost savings - 35% 48% 56%
SAP Rating E (53) D (68) C (75) C (78)
EI Rating F (33) D (65) C (75) C (79)
Approximate CO 2 emissions kg/m 2/year 575 240 174 144
Percentage CO 2 improvement - 55% 68% 73%
* - Actual costs of installation (includes energy centre built out-with building)
Case study HTT-4E: System built Multi-storey flat 1950-64 - mid floor gable end (2 bed) (69m 2)
Fuel type: Electricity
Baseline annual fuel costs: £808
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor - - - -
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,765 £10,265 £13,965
Annual fuel cost savings - £212 £431 £466
Percentage annual fuel cost savings - 26% 53% 58%
SAP Rating D (63) C (72) B (83) B (84)
EI Rating E (44) E (54) C (73) C (76)
Approximate CO 2 emissions kg/m 2/year 449 351 206 182
Percentage CO 2 improvement - 22% 55% 60%
Case study HTT-4G: System built Multi-storey flat 1950-64 - mid floor gable end (electric - gas community heating) (2 bed) (69m 2)
Fuel type: Electricity - Gas
Baseline annual fuel costs: £808
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor - - - -
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Gas communal heating
(£12,209*)
- -
Heating system controls Manual charge control Flat rate charging, programmer and TRVs (included in communal heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam From communal heating with 80mm factory applied foam (included in communal heating costs) - -
Secondary space heating Electric room heater None - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £15,924 £21,424 £25,124
Annual fuel cost savings - £262 £411 £445
Percentage annual fuel cost savings - 32% 51% 55%
SAP Rating D (63) C (73) B (81) B (82)
EI Rating E (44) C (73) B (83) B (85)
Approximate CO 2 emissions kg/m 2/year 449 187 117 105
Percentage CO 2 improvement - 55% 71% 75%
* - Actual costs of installation (includes energy centre built out-with building)

Hard-to-treat case studies 5 - 8 - System built flats 1950-64

Hard-to-Treat case studies 5 - 8 System built flats 1950-64

Case study HTT-5E: 1950-64 System built external deck access flat, ground floor gable end (2 bed) (58m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,082
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,765 £10,265 £15,165
Annual fuel cost savings - £273 £535 £635
Percentage annual fuel cost savings - 25% 49% 59%
SAP Rating E (45) D (59) C (72) C (77)
EI Rating F (26) F (36) E (54) D (63)
Approximate CO 2 emissions kg/m 2/year 730 581 377 299
Percentage CO 2 improvement - 21% 48% 60%
Case study HTT-5G: 1950-64 System built external deck access flat, ground floor gable end (2 bed) (58m 2)
Fuel type: Gas
Baseline annual fuel costs: £983
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £3,715 £9,215 £14,115
Annual fuel cost savings - £74 £503 £568
Percentage annual fuel cost savings - 8% 51% 58%
SAP Rating E (47) E (51) C (75) C (78)
EI Rating E (44) E (48) C (77) B (81)
Approximate CO 2 emissions kg/m 2/year 425 392 171 142
Percentage CO 2 improvement - 8% 61% 67%
Case study HTT-6E: 1950-64 System built external deck access flat, mid floor gable end (2 bed) (67m 2)
Fuel type: Electricity
Baseline annual fuel costs: £835
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor - - - -
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,765 £10,265 £13,965
Annual fuel cost savings - £212 £460 £493
Percentage annual fuel cost savings - 25% 55% 59%
SAP Rating D (61) C (70) B (82) B (84)
EI Rating E (41) E (51) C (72) C (75)
Approximate CO 2 emissions kg/m 2/year 486 385 216 190
Percentage CO 2 improvement - 21% 56% 61%
Case study HTT-6G: 1950-64 System built external deck access flat, mid floor gable end (2 bed) (67m 2)
Fuel type: Gas
Baseline annual fuel costs: £836
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor - - - -
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £3,718 £9,218 £12,918
Annual fuel cost savings - £90 £452 £480
Percentage annual fuel cost savings - 11% 54% 57%
SAP Rating D (58) D (62) B (81) B (82)
EI Rating D (55) D (60) B (84) B (86)
Approximate CO 2 emissions kg/m 2/year 310 275 109 100
Percentage CO 2 improvement - 13% 65% 68%

The No Fines archetypes ( HTT-7E, HTT-7G, HTT-8E and HTT-8G) have been modelled using actual u-values based on drawings of the building's construction. Improved u-values were calculated based on insulation specification.

  • The main walls were calculated as having a u-value of 1.53 W/m 2K and 0.713 W/m 2K when improved by installing 75mm of external insulation cladding.
  • The sheltered wall was calculated as having a u-value of 0.923 W/m 2K and 0.546 W/m2K when improved by installing 75mm of external insulation cladding.
  • The floors when improved were calculated to have a u-value of 0.302 W/m 2K.

These have been modelled here with all the default values

  • 2.0 W/m 2K for the main walls and 0.6 W/m 2K when improved
  • the sheltered wall as 1.11 W/m 2K and 0.48 W/m 2K when improved
  • The floors of the ground floor archetype (HTT-7) are defaulted as having an improved u-value of 0.34 W/m 2K.

In this instance the baseline "user defined" fabric performance of the dwelling is greater than the default assumptions and have better results. However, when the improvements are modelled, the improved fabric performance is marginally poorer than the default assumed improved settings. Therefore, the default results are slightly better when the fabric improvements are modelled.

Case study HTT-7E: 1950-1964 No Fines concrete flat (2 bed) - ground floor, gable end (user defined u-values) (65m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,099
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,765 £10,265 £15,165
Annual fuel cost savings - £251 £420 £531
Percentage annual fuel cost savings - 23% 38% 48%
SAP Rating E (47) D (59) D (67) C (73)
EI Rating F (28) F (36) E (46) E (54)
Approximate CO 2 emissions kg/m 2/year 676 557 433 357
Percentage CO 2 improvement - 18% 36% 47%
Case study HTT-7G: 1950-64 No Fines concrete flat (2 bed) - ground floor, gable end (user defined u-values) (65m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,003
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003) (£3,700) - 100% double glazing (post 2003) (£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £3,718 £12,018 £16,918
Annual fuel cost savings - £78 £446 £524
Percentage annual fuel cost savings - 8% 44% 52%
SAP Rating E (49) E (53) C (72) C (76)
EI Rating E (46) E (49) C (73) C (78)
Approximate CO 2 emissions kg/m 2/year 397 365 191 159
Percentage CO 2 improvement - 8% 52% 60%
Case study HTT-7E: 1950-1964 No Fines concrete flat (2 bed) - ground floor, gable end (default u-values) (65m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,224
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,765 £10,265 £15,165
Annual fuel cost savings - £307 £563 £683
Percentage annual fuel cost savings - 25% 46% 56%
SAP Rating E (41) D (56) D (68) C (74)
EI Rating F (23) F (32) E (48) D (57)
Approximate CO 2 emissions kg/m 2/year 758 606 421 338
Percentage CO 2 improvement - 21% 45% 55%
Case study HTT-7G: 1950-64 No Fines concrete flat (2 bed) - ground floor, gable end (default u-values) (65m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,079
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof - - - -
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £3,718 £12,018 £16,918
Annual fuel cost savings - £77 £532 £608
Percentage annual fuel cost savings - 7% 49% 56%
SAP Rating E (45) E (49) C (73) C (76)
EI Rating E (42) E (45) C (74) C (78)
Approximate CO 2 emissions kg/m 2/year 432 401 186 155
Percentage CO 2 improvement - 7% 57% 65%
Case study HTT-8E: 1950-64 No Fines concrete flat (2 bed) - top floor, gable end (user defined u-values) (65m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,533
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor - - - -
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £5,265 £11,048 £14,748
Annual fuel cost savings - £787 £982 £1,017
Percentage annual fuel cost savings - 51% 64% 66%
SAP Rating F (29) D (64) C (74) C (75)
EI Rating G (13) E (42) D (56) D (59)
Approximate CO 2 emissions kg/m 2/year 963 484 344 320
Percentage CO 2 improvement - 49% 65% 66%
Case study HTT-8G: 1950-1964 No Fines concrete flat (2 bed) - top floor, gable end (user defined u-values) (65m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,253
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor - - - -
Roof No insulation 100mm at joists (£500) 250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,218 £12,801 £16,501
Annual fuel cost savings - £398 £785 £797
Percentage annual fuel cost savings - 32% 63% 64%
SAP Rating F (37) D (56) C (77) C (77)
EI Rating F (35) E (53) C (79) C (79)
Approximate CO 2 emissions kg/m 2/year 512 333 150 149
Percentage CO 2 improvement - 34% 70% 72%
Case study HTT-8E: 1950-1964 No Fines concrete flat (2 bed) - top floor, gable end (default u-values) (65m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,676
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor - - - -
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £5,265 £11,048 £14,748
Annual fuel cost savings - £825 £1,142 £1,176
Percentage annual fuel cost savings - 49% 68% 70%
SAP Rating F (25) D (59) C (74) C (76)
EI Rating G (9) F (36) D (57) D (60)
Approximate CO 2 emissions kg/m 2/year 1057 558 332 309
Percentage CO 2 improvement - 47% 68% 71%
Case study HTT-8G: 1950-1964 No Fines concrete flat (2 bed) - top floor, gable end (default u-values) (65m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,325
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - External insulation
(£5,500)
-
Floor - - - -
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£15)
- -
Solar PVs None - - -
Total cost of all measures applied since baseline - £4,218 £12,801 £16,501
Annual fuel cost savings - £379 £851 £877
Percentage annual fuel cost savings - 29% 64% 66%
SAP Rating F (34) E (52) C (76) C (77)
EI Rating F (32) E (48) C (78) C (80)
Approximate CO 2 emissions kg/m 2/year 546 375 153 145
Percentage CO 2 improvement - 31% 72% 74%

Case studies 9 - 12 - Concrete, Steel frame and timber houses

Case studies 9 - 12 Concrete, Steel frame and timber houses

The following Swedish timber archetype ( HTT-9E and HTT-9G) use u-values based on actual wall construction and u-value calculations and make comparisons against the default values in RdSAP.

The user defined u-values of the main wall were calculated using record drawings of the wall construction and specification of insulation materials. Either external or internal wall insulation could be applied. The improved u-value could be obtained from either insulation method. The u-values modelled were: 1.241 W/m 2K (pre) / 0.253 W/m 2K (post).

These were compared against the default u-values for system built 2.0 W/m 2K (pre) and the default unknown wall insulation of 0.6 W/m 2K (post). Where the previous example used 150mm floor ins to obtain a u-value of 0.17 W/m 2K, based on specifications, these examples use the default unknown retro floor insulation and gives the u-value of 0.35 W/m 2K.

For this case study the fabric performance of the dwelling before and after improvements is greater than the default assumptions built into RdSAP. The RdSAP results are therefore better for this particular archetype by using details of the actual property's characteristics.

Case study HTT-9E: Swedish timer frame semi-detached (3 bed - 1946) (user defined u-values) (90m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,919
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - Internal or external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 250mm at joists
(£500)
- -
Windows 100% single glazing 100% double glazing (post 2003)
(£3,700)
- -
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £5,268 £10,768 £19,968
Annual fuel cost savings - £881 £1,148 £1,238
Percentage annual fuel cost savings - 46% 60% 65%
SAP Rating F (29) D (59) C (70) C (79)
EI Rating G (13) F (36) E (50) D (60)
Approximate CO 2 emissions kg/m 2/year 872 494 353 284
Percentage CO 2 improvement - 44% 60% 68%
Case study HTT-9G: Swedish timer frame semi-detached (3 bed - 1946) (user defined u-values) (90m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,559
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - Internal or external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £4,218 £12,801 £25,701
Annual fuel cost savings - £342 £903 £993
Percentage annual fuel cost savings - 22% 58% 64%
SAP Rating F (37) E (50) C (73) B (82)
EI Rating F (34) E (45) C (73) B (82)
Approximate CO 2 emissions kg/m 2/year 470 360 169 116
Percentage CO 2 improvement - 23% 64% 75%
Case study HTT-9E: Swedish timer frame semi-detached (3 bed - 1946) (default u-values) (90m 2)
Fuel type: Electricity
Baseline annual fuel costs: £2,189
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - Internal or external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 250mm at joists
(£500)
- -
Windows 100% single glazing 100% double glazing (post 2003)
(£3,700)
- -
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £5,265 £10,765 £19,965
Annual fuel cost savings - £956 £1,317 £1,377
Percentage annual fuel cost savings - 44% 60% 63%
SAP Rating F (22) E (52) D (66) C (73)
EI Rating G (7) F (28) E (44) E (51)
Approximate CO 2 emissions kg/m 2/year 1001 594 404 351
Percentage CO 2 improvement - 41% 60% 65%
Case study HTT-9G: Swedish timer frame semi-detached (3 bed - 1946) (default u-values) (90m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,700
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - Internal or external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £4,218 £12,801 £25,701
Annual fuel cost savings - £322 £989 £1,061
Percentage annual fuel cost savings - 19% 58% 62%
SAP Rating F (32) E (43) C (71) C (79)
EI Rating F (30) E (39) C (70) C (78)
Approximate CO 2 emissions kg/m 2/year 517 414 187 141
Percentage CO 2 improvement - 20% 64% 72%
Case study HTT-10E: 1950-1982 Timber frame semi-detached (3 bed - late 1960 / early 1970s) (92m 2)
Fuel type: Electricity
Baseline annual fuel costs: £1,633.50
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - -
Floor No insulation - - Insulation
(£1,200)
Roof 12mm insulation 250mm at joists
(£500)
- -
Windows 100% single glazing 100% double glazing (post 2003)
(£3,700)
- -
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £5,268 - £14,468
Annual fuel cost savings - £761 - £813
Percentage annual fuel cost savings - 47% - 50%
SAP Rating E (41) D (66) - C (74)
EI Rating F (22) E (45) - E (51)
Approximate CO 2 emissions kg/m 2/year 682 399 - 346
Percentage CO 2 improvement - 41% - 49%
Case study HTT-10G: 1950-1982 Timber frame semi-detached (3 bed - late 1960 / early 1970s) (92m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,354
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - - -
Floor No insulation - - Insulation
(£1,200)
Roof 12mm insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £4,218 £7,301 £20,201
Annual fuel cost savings - £279 £650 £710
Percentage annual fuel cost savings - 21% 48% 52%
SAP Rating E (45) D (56) C (71) C (79)
EI Rating E (41) E (51) C (71) C (78)
Approximate CO 2 emissions kg/m 2/year 393 306 185 139
Percentage CO 2 improvement - 23% 53% 64%
Case study HTT-11E: System built concrete semi-detached house (Orlit - 3 bed - 1930-49) (104m 2)
Fuel type: Electricity
Baseline annual fuel costs: £2,347
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 250mm at joists
(£500)
- -
Windows 100% single glazing 100% double glazing (post 2003)
(£3,700)
- -
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £5,265 £10,765 £19,965
Annual fuel cost savings - £1,020 £1,511 £1,575
Percentage annual fuel cost savings - 43% 64% 67%
SAP Rating F (23) E (54) C (71) C (78)
EI Rating G (8) F (30) E (51) D (59)
Approximate CO 2 emissions kg/m 2/year 925 543 331 279
Percentage CO 2 improvement - 41% 64% 70%
Case study HTT-11G: System built concrete semi-detached house (Orlit - 3 bed - 1930-49) (104m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,832
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
- -
Heating system controls Programmer Time and temperature zone controls
(£300)
- -
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £7,018 £12,801 £25,701
Annual fuel cost savings - £862 £1,136 £1,215
Percentage annual fuel cost savings - 47% 62% 66%
SAP Rating F (33) D (64) C (75) B (82)
EI Rating F (31) D (60) C (74) B (82)
Approximate CO 2 emissions kg/m 2/year 483 239 157 111
Percentage CO 2 improvement - 51% 68% 76%
Case study HTT-12E: System built steel frame semi-detached house (BISF - 3 bed - 1930-49) (89m 2)
Fuel type: Electricity
Baseline annual fuel costs: £2,108
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 250mm at joists
(£500)
- -
Windows 100% single glazing 100% double glazing (post 2003)
(£3,700)
- -
Open chimneys None - - -
Heating system Old (large volume) storage heaters Fan storage heaters
(£1,050)
- -
Heating system controls Manual charge control Automatic charge control (included in storage heating costs) - -
Hot water system Electric immersion with 25mm factory applied foam Electric immersion with 80mm factory applied foam (included in storage heating costs) - -
Secondary space heating Electric room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £5,265 £10,765 £19,965
Annual fuel cost savings - £905 £1,360 £1,418
Percentage annual fuel cost savings - 43% 65% 67%
SAP Rating F (23) E (53) C (71) C (78)
EI Rating G (8) F (30) E (51) D (59)
Approximate CO 2 emissions kg/m 2/year 970 576 345 291
Percentage CO 2 improvement - 39% 64% 69%
Case study HTT-12G: System built steel frame semi-detached house (BISF - 3 bed - 1930-49) (89m 2)
Fuel type: Gas
Baseline annual fuel costs: £1,653
Energy Efficiency Measure Baseline: 1990 SHQS 2015 Further Measures 2020 Advanced Measures 2050
Walls No insulation - 100mm external insulation
(£5,500)
-
Floor No insulation - - Insulation
(£1,200)
Roof No insulation 100mm at joists
(£500)
250mm at joists
(£283)
-
Windows 100% single glazing 100% double glazing (pre 2003)
(£3,700)
- 100% double glazing (post 2003)
(£3,700)
Open chimneys None - - -
Heating system Full central heating, boiler efficiency 66% - Full central heating, boiler efficiency 90% (condensing combi)
(£2,500)
-
Heating system controls Programmer - Time and temperature zone controls
(£300)
-
Hot water system Cylinder thermostat with 25mm factory applied foam - - -
Secondary space heating Gas room heater - - -
Ventilation natural - - -
Low energy lighting None 100%
(£18)
- -
Solar PVs None - - 20% of roof area
(£8,000)
Total cost of all measures applied since baseline - £7,018 £12,801 £25,701
Annual fuel cost savings - £761 £1,014 £1,086
Percentage annual fuel cost savings - 46% 61% 66%
SAP Rating F (33) D (63) C (74) B (81)
EI Rating F (31) D (60) C (74) B (82)
Approximate CO 2 emissions kg/m 2/year 506 254 165 118
Percentage CO 2 improvement - 49% 68% 77%

Contact

Email: Agnes Meany