| Measure | Grant | Net cost | Saving / yr | Payback | Grade effect |
|---|---|---|---|---|---|
| Low energy lighting | — | £25 | £9 | 2.7 yrs | +0.3 pts |
| Floor insulation | — | £1,200 – £200 | £215 | 3.3 yrs | +6.0 pts · reaches D |
| Solar photovoltaic panels | — | £5,500 – £500 | £199 | 15.1 yrs | +5.5 pts |
| Solar water heating | — | £6,000 – £0 | £167 | 18.0 yrs | +4.6 pts |
| Solid wall insulation | — | £14,000 – £0 | £233 | 30.1 yrs | +6.5 pts · reaches C |
| Double glazing(optional, beyond C) | — | £6,500 – £500 | £78 | 45.0 yrs | +2.2 pts |
Grants verified 20 August 2026. Costs are the register’s indicative ranges. 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 £823 a year — a 6.0% annual return on £13,725.
Restated at the fuel prices assumed in July 2026. This certificate, assessed in 2019, states £1,574 a year at the prices assumed then. Modelled costs, not a bill.
Sold prices
Estimated today: £334,245 HPI-indexed estimate, not a valuation
Castlegate: 60 sales since 1995 · £233,080 average over 10 years
Schools nearby
The schools’ own performance — Progress 8 shows value added, not just raw results.
| School | Phase | Distance | Progress |
|---|---|---|---|
| St Wulfram's National Church of England Primary School | Primary | 0.1 mi | — |
| The Little Gonerby Church of England Primary Academy, Grantham | Primary | 0.3 mi | — |
| Saint Mary's Catholic Voluntary Academy | Primary | 0.4 mi | — |
| The King's School, Grantham | Secondary | under 0.1 mi | Progress 8 +1.10 · well above average (2023/24) |
| Kesteven and Grantham Girls' School | Secondary | 0.3 mi | Progress 8 +1.04 · well above average (2023/24) |
| Charles Read Academy | Secondary | 0.4 mi | Progress 8 +0.58 · well above 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 E01026353, to 2026-06. An LSOA holds about 1,500 people, so this covers far more than one street.
Castlegate
How this home sits against its street.