3 Mariners Heights, Penarth CF64 1QJ

Mid-Terrace flat · Built 1983-1990 · 47 m² · Owner-Occupied · Room heaters, electric

Upgrade Plan

DC for £1,023 · £1,023 a gradeGet upgrade quotes
MeasureGrantNet costSaving / yrPaybackGrade effect
Hot water cylinder insulation£15 – £30£1130.2 yrs+4.0 pts
High-retention storage heaters£800 – £1,200£2613.8 yrs+9.2 pts · reaches C
Low energy lighting(optional, beyond C)£25£64.3 yrs+0.2 pts
Floor insulation(optional, beyond C)£4,000 – £6,000£13237.8 yrs+4.7 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

£1,277
per year at grade D
£765
per year at grade C

The full plan saves £374 a year — a 36.6% annual return on £1,023.

Restated at the fuel prices assumed in July 2026. This certificate, assessed in 2021, states £825 a year at the prices assumed then. Modelled costs, not a bill.

Sold prices

28 August 2013£107,000
19 October 2007£112,000
15 November 2004£105,000
24 January 2003£79,250
14 May 1999£49,450

Estimated today: £154,906 HPI-indexed estimate, not a valuation

Mariners Heights: 81 sales since 1995 · £151,645 average over 10 years

Schools nearby

The DfE register covers England. Welsh schools are held in a separate Welsh Government register, which we have not ingested yet.

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.

8.4
crimes a month
92
in the last 12 months
Violence and sexual offences
most common · 38% of the total

Police.uk street-level data for LSOA W01001123, to 2026-06. An LSOA holds about 1,500 people, so this covers far more than one street.

Mariners Heights

How this home sits against its street.

31
graded homes
68.5
average score
C
most common grade
-10.5
this home vs street
Energy data © Crown copyright, EPB Register© HM Land Registry, OGL v3We grade homes, never neighbourhoods.