Recently pulled together a league table of the various measure of heating efficiency I intend to publish on the main site at some point soon. Here is it - hope you find it useful!
Heating (kWhrs) Saved from Efficiency Measure
| Detached House | Semi Detached House | Mid Terrace House | Detached Bungalow | Flat | |
|---|---|---|---|---|---|
| Solid Wall Insulation | 2,107.1 | 1,250.0 | 773.8 | 845.2 | 583.3 |
| Cavity Wall Insulation | 1,190.5 | 738.1 | 452.4 | 500.0 | 345.2 |
| Installing Loft Insulation (from none) | 1,095.2 | 654.8 | 583.3 | 940.5 | 0.0 |
| Single to Double Glazing Windows | 972.6 | 691.1 | 563.1 | 563.1 | 460.7 |
| Turning Down Heating by 2 degrees | 854.3 | 657.1 | 676.9 | 854.3 | 576.1 |
| Installing Hot Water Pipe Insulation | 595.2 | 357.1 | 357.1 | 535.7 | 357.1 |
| Solar Water Heating | 530.5 | 397.9 | 344.8 | 397.9 | 0.0 |
| Installing Hot Water Tank Insulation | 476.2 | 511.9 | 511.9 | 500.0 | 535.7 |
| Under Floor Insulation | 333.3 | 190.5 | 131.0 | 333.3 | 0.0 |
| Double to Triple Glazing Windows | 243.2 | 172.8 | 140.8 | 140.8 | 115.2 |
| Install Water Efficient Shower Head | 175.2 | 131.4 | 131.4 | 175.2 | 87.6 |
| Turn off heating in unused rooms | 116.1 | 87.6 | 87.6 | 116.1 | 54.8 |
| Improving Hot Water Tank Insulation | 107.1 | 119.0 | 119.0 | 119.0 | 119.0 |
| Improving Loft Insultation | 95.2 | 59.5 | 47.6 | 83.3 | 0.0 |
| Radiator Reflector Panels | 2.6 | 1.0 | 0.9 | 0.9 | 0.6 |
| Draught Proofing Doors | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 |