| Measure | Grant | Net cost | Saving / yr | Payback | Grade effect |
|---|---|---|---|---|---|
| Hot water cylinder insulation | — | £23 – £300typical | £103 | 1.6 yrs | +6.2 pts · reaches E |
| Loft insulation | — | £225typical | £57 | 3.9 yrs | +3.5 pts |
| Heating controls | — | £400typical | £44 | 9.1 yrs | +2.7 pts |
| Low energy lighting | — | £30 – £75typical | £5 | 10.0 yrs | +0.3 pts |
| Cavity wall insulation | — | £1,000typical | £90 | 11.1 yrs | +5.4 pts |
| Band A condensing boiler | — | £2,600typical | £74 | 35.2 yrs | +4.5 pts · reaches D |
| Solar water heating | — | £5,000typical | £93 | 50+ yrs | +5.7 pts |
| Solar photovoltaic panels | — | £4,500 – £9,000typical | £111 | 50+ yrs | +6.7 pts · reaches C |
Grants verified 20 August 2026. Costs are the register’s indicative ranges, except where marked typical, which this certificate did not price and which are taken instead from comparable homes of the same type. Savings are restated at the fuel prices assumed in July 2026. Points per measure are estimated from 19.9 million certificates and rescaled to this home’s own certificate delta; the total is the register’s figure.
Running costs
The full plan saves £578 a year — a 3.6% annual return on £16,189.
Energy costs as modelled on the certificate, not a bill. This fuel has too few recent certificates to restate at today's prices.
Sold prices
Estimated today: £616,763 HPI-indexed estimate, not a valuation
Derwent Drive: 81 sales since 1995 · £573,881 average over 10 years
Schools nearby
The schools’ own performance — Progress 8 shows value added, not just raw results.
| School | Phase | Distance | Progress |
|---|---|---|---|
| Harris Primary Academy Kenley | Primary | 0.6 mi | — |
| Atwood Primary School | Primary | 0.8 mi | — |
| Gresham Primary School | Primary | 0.8 mi | — |
| Riddlesdown Collegiate | Secondary | 0.2 mi | Progress 8 +0.14 · average (2023/24) |
| Warlingham School | Secondary | 1.2 mi | Progress 8 -0.18 · average (2023/24) |
| Thomas More Catholic School | Secondary | 1.7 mi | Progress 8 -0.13 · average (2023/24) |
Schools from the DfE register, performance from the KS4 performance tables. Progress 8 is a GCSE measure, so primaries have none. Distance is straight-line from the postcode, not a catchment: admission is decided by the school, not by us.
Area context
Police-recorded crime for the wider neighbourhood, not this address. We grade homes, never neighbourhoods — so this is reported as a count, not a rating.
Police.uk street-level data for LSOA E01001104, to 2026-06. An LSOA holds about 1,500 people, so this covers far more than one street.
Derwent Drive
How this home sits against its street.