4 Mark Close, Portsmouth PO3 5JB

Semi-Detached house · Built 1967-1975 · 84 m² · Owner-Occupied · Boiler and radiators, mains gas

Upgrade Plan

DB for £8,695 · £4,348 a gradeGet upgrade quotes
MeasureGrantNet costSaving / yrPaybackGrade effect
Floor insulation£1,200 – £200£1106.3 yrs+5.6 pts
Low energy lighting£45£59.3 yrs+0.2 pts
Heating controls£450£4011.2 yrs+2.1 pts
Band A condensing boiler£3,000 – £0£6822.1 yrs+3.5 pts · reaches C
Solar photovoltaic panels£5,500 – £500£10229.4 yrs+5.2 pts
Solar water heating£6,000 – £0£8635.0 yrs+4.4 pts · reaches B

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

£1,349
per year at grade D
£938
per year at grade B

The full plan saves £411 a year — a 4.7% annual return on £8,695.

Restated at the fuel prices assumed in July 2026. This certificate, assessed in 2019, states £854 a year at the prices assumed then. Modelled costs, not a bill.

Sold prices

29 May 2020£259,000

Estimated today: £316,128 HPI-indexed estimate, not a valuation

Mark Close: 7 sales since 1995 · £319,667 average over 10 years

Schools nearby

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

SchoolPhaseDistanceProgress
Gatcombe Park Primary SchoolPrimary0.2 mi
King's Academy Northern Parade (Junior)Primary0.5 mi
King's Academy Northern Parade (Infant)Primary0.5 mi
Trafalgar SchoolSecondary0.2 miProgress 8 -0.19 · average (2023/24)
UTC PortsmouthSecondary0.3 miProgress 8 -0.47 · below average (2023/24)
Admiral Lord Nelson SchoolSecondary1.0 miProgress 8 -0.35 · 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.

8.4
crimes a month
76
in the last 12 months
Violence and sexual offences
most common · 36% of the total

Police.uk street-level data for LSOA E01017085, to 2026-06. An LSOA holds about 1,500 people, so this covers far more than one street.

Mark Close

How this home sits against its street.

6
graded homes
67.7
average score
C
most common grade
-6.7
this home vs street
Energy data © Crown copyright, EPB Register© HM Land Registry, OGL v3We grade homes, never neighbourhoods.