Analysis, not a count
Which areas are actually converting their oil homes
This page is different from the rest of the site. Every other figure here is counted directly from certificates. This one is calculated, by comparing each council against what its own housing stock would predict. The method is set out below in full, including two earlier versions of it that were wrong, and the working ships as a CSV so you can check it rather than trust it.
Ranking councils on how many heat pumps they have just re-ranks them by how rural they are. Cornwall has more oil homes than anywhere, so of course it has more conversions. The useful question is different: of the oil and LPG homes an area actually has, how many is it converting?
A ratio of 1.00 means an area is converting exactly as many as its housing stock predicts. Above 1.00 is faster. Below is slower. Nationally 25,908 of 307,528 re-assessed oil and LPG homes have converted, which is 8.4%.
Converting faster than their housing stock predicts
| # | Council | Oil/LPG homes | Converted | Expected | Ratio |
|---|---|---|---|---|---|
| 1 | North Hertfordshire | 854 | 163 | 79 | 2.06 |
| 2 | York | 358 | 63 | 31 | 2.02 |
| 3 | Boston | 1,272 | 221 | 118 | 1.88 |
| 4 | Newark and Sherwood | 1,170 | 186 | 109 | 1.70 |
| 5 | Denbighshire | 1,545 | 194 | 120 | 1.61 |
| 6 | West Oxfordshire | 1,657 | 213 | 136 | 1.56 |
| 7 | Conwy | 1,450 | 182 | 120 | 1.52 |
| 8 | Fenland | 1,658 | 211 | 140 | 1.51 |
| 9 | Lewes | 752 | 86 | 60 | 1.43 |
| 10 | Winchester | 1,459 | 183 | 128 | 1.43 |
Converting slower than their housing stock predicts
| # | Council | Oil/LPG homes | Converted | Expected | Ratio |
|---|---|---|---|---|---|
| 1 | Wyre | 396 | 13 | 35 | 0.37 |
| 2 | Hinckley and Bosworth | 456 | 16 | 38 | 0.42 |
| 3 | Solihull | 312 | 12 | 28 | 0.43 |
| 4 | Leeds | 349 | 14 | 27 | 0.51 |
| 5 | Dover | 538 | 25 | 47 | 0.53 |
| 6 | Maidstone | 842 | 37 | 66 | 0.56 |
| 7 | Doncaster | 551 | 26 | 45 | 0.57 |
| 8 | Canterbury | 391 | 20 | 33 | 0.60 |
| 9 | Braintree | 1,723 | 97 | 154 | 0.63 |
| 10 | Lichfield | 495 | 28 | 44 | 0.63 |
How this is calculated
Indirect standardisation, the same technique behind a standardised mortality ratio. Nothing is fitted or predicted; it is arithmetic on counts.
- Take every home whose earliest certificate showed oil or LPG as its main heating fuel, and which has been assessed again since. There are 307,528 of them.
- Count how many now show a heat pump on their latest certificate: 25,908.
- Split that population into strata of property type, built form and construction age band, and work out the national conversion rate for each.
- A council's expected count is the sum of its own homes in each stratum multiplied by the national rate for it. The ratio is actual over expected.
Why start from the first certificate rather than the current one: a home that converts from oil to a heat pump stops being an oil home. Measuring the share of today's oil homes with a heat pump would be near zero by construction. The only way to see a conversion is to look at where a property started and where it ended up.
91 strata of 300 or more homes are used, covering 94% of the population. Councils with an expected count below 25 are left out, which is why only 144 of 318 appear: the rest do not have enough oil or LPG stock to measure. Summed nationally the ratio comes to exactly 1.00, which it must if the expected counts are right.
Two earlier versions of this were wrong
Worth saying plainly, because it shows what this measure is guarding against. The first attempt standardised heat pump adoption across all homes. It put Hammersmith and Fulham, Westminster and Kensington and Chelsea at the top, boroughs that are barely off the gas grid at all. The reason was that between 67% and 100% of their heat pumps sit in properties built since 2000: communal air source systems specified by developers in new blocks of flats, nothing to do with this grant.
The second attempt restricted the population to off-grid homes, which did not fix it, because "off the gas grid" includes electrically heated flats and inner London is full of them. Westminster went up rather than down. Only restricting to homes that actually started on oil or LPG, and measuring the change, answers the question the grant is about.
What it does not tell you
It controls for housing stock and nothing else: not local incomes, not how many MCS-certified installers work in the area, not off-street space for an outdoor unit. It also only sees homes that have been assessed twice, which skews towards property that has been sold or re-let. A ratio of 1.00 means typical, not good; the national conversion rate is only 8.4%.
The straight counts
Every other table on this site is a direct count with no calculation involved.