115a Southdown Road, Harpenden AL5 1QQ

End-Terrace maisonette · Built 1900-1929 · 49 m² · Owner-Occupied · Room heaters, electric

Upgrade Plan

EC for £10,825 · £5,413 a gradeGet upgrade quotes
MeasureGrantNet costSaving / yrPaybackGrade effect
Draughtproofing£80 – £120£2730.4 yrs+5.5 pts
Loft insulation£100 – £350£1541.5 yrs+3.1 pts
High-retention storage heaters£1,200 – £1,800£6372.4 yrs+12.9 pts · reaches D
Solid wall insulation£4,000 – £14,000£35025.7 yrs+7.1 pts · reaches C
Double glazing(optional, beyond C)£3,300 – £6,500£11741.8 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

£2,510
per year at grade E
£979
per year at grade C

The full plan saves £1,414 a year — a 13.1% annual return on £10,825.

Restated at the fuel prices assumed in July 2026. This certificate, assessed in 2023, states £2,596 a year at the prices assumed then. Modelled costs, not a bill.

Sold prices

19 December 2024£252,500

Estimated today: £248,539 HPI-indexed estimate, not a valuation

Southdown Road: 235 sales since 1995 · £476,728 average over 10 years

Schools nearby

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

SchoolPhaseDistanceProgress
The Grove Junior SchoolPrimary0.3 mi
The Grove Infant and Nursery SchoolPrimary0.3 mi
St Dominic Catholic Primary SchoolPrimary0.4 mi
Sir John Lawes SchoolSecondary1.1 miProgress 8 +0.79 · well above average (2023/24)
St George's SchoolSecondary1.1 miProgress 8 +0.65 · well above average (2023/24)
Katherine Warington SchoolSecondary1.2 miProgress 8 +0.48 · 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.

8.3
crimes a month
83
in the last 12 months
Violence and sexual offences
most common · 35% of the total

Police.uk street-level data for LSOA E01023697, to 2026-06. An LSOA holds about 1,500 people, so this covers far more than one street.

Southdown Road

How this home sits against its street.

96
graded homes
70.8
average score
C
most common grade
-29.8
this home vs street
Energy data © Crown copyright, EPB Register© HM Land Registry, OGL v3We grade homes, never neighbourhoods.