21 Sonters Down, Rettendon Common, Chelmsford CM3 8EU

End-Terrace flat · Built 1976-1982 · 63 m² · Owner-Occupied · Boiler and radiators, mains gas

Upgrade Plan

Get upgrade quotes
MeasureGrantNet costSaving / yrPaybackGrade effect
Hot water cylinder insulation(optional, beyond C)£15 – £400£1211.7 yrs+3.4 pts
Low energy lighting(optional, beyond C)£30£64.8 yrs+0.2 pts
Cavity wall insulation(optional, beyond C)£500 – £1,500£1069.5 yrs+3.0 pts
Band A condensing boiler(optional, beyond C)£2,200 – £3,000£8729.9 yrs+2.4 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

£938
per year at grade C
£618
per year at grade C

Restated at the fuel prices assumed in July 2026. This certificate, assessed in 2017, states £621 a year at the prices assumed then. Modelled costs, not a bill.

Sold prices

23 September 2021£210,000
11 December 2017£176,000
22 June 2007£134,995
12 December 2003£102,000
8 December 1997£16,560

Estimated today: £218,618 HPI-indexed estimate, not a valuation

Sonters Down: 58 sales since 1995 · £233,654 average over 10 years

Schools nearby

The schools’ own performance — Progress 8 shows value added, not just raw results.

SchoolPhaseDistanceProgress
Rettendon Primary SchoolPrimary0.2 mi
St Luke's Park Primary SchoolPrimary0.8 mi
Hilltop Junior SchoolPrimary1.8 mi
Beauchamps High SchoolSecondary1.9 miProgress 8 -0.02 · average (2023/24)
William de Ferrers SchoolSecondary2.6 miProgress 8 -0.41 · below average (2023/24)
The Bromfords SchoolSecondary3.1 miProgress 8 -0.50 · below 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.

17.6
crimes a month
194
in the last 12 months
Violence and sexual offences
most common · 51% of the total

Police.uk street-level data for LSOA E01034088, to 2026-06. An LSOA holds about 1,500 people, so this covers far more than one street.

Sonters Down

How this home sits against its street.

22
graded homes
58.7
average score
D
most common grade
+10.3
this home vs street
Energy data © Crown copyright, EPB Register© HM Land Registry, OGL v3We grade homes, never neighbourhoods.