Solar panels, heat pumps and insulation in Wandsworth Town conservation area
In the Wandsworth Town conservation area (Wandsworth), external wall insulation needs planning permission, and so does an air source heat pump on a wall or roof facing the road; one at the back or side, internal and loft insulation and solar panels on a roof slope normally do not. The area has 34 listed buildings; on a listed building solar panels and heat pumps are not permitted development at all and need planning permission and listed building consent. 1,401 homes inside the boundary have an energy certificate: 35.2% are solid-wall homes with no wall insulation, 47.5% heat with a gas boiler and 28.5% are rated D–G; 11 have a heat pump. EPC register November 2026; rules as at 21 October 2026.
Data: EPC register November 2026 (latest certificate per home), conservation area boundaries 3 November 2026, permitted development rules as at 21 October 2026 · calculated 5 November 2026 · Methodology and sources
1,401homes with an energy certificate
35.2%solid walls, no insulation
47.5%heated by a gas boiler
11heat pumps
Article 4: Wandsworth does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Wandsworth Town
Work (house, not listed)
In a conservation area
Rule
Air source heat pump on a wall or roof facing the road, or nearer the road than the house
Planning permission needed
Part 14 Class G, G.1(j)
Air source heat pump at the back or side (outdoor unit up to 1.5 m³, MCS Planning Standards, one per house — two on a detached house)
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 14 Class G
Solar panels on a pitched roof (up to 0.2 m proud, not above the ridge)
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 14 Class A, A.2(c)
Solar panels on a wall, balcony or roof enclosure facing the road
Planning permission needed
Part 14 Class A, A.2(e)
Solar panels on a flat roof (up to 0.6 m above the roof)
Prior approval of appearance from the council, unless an Article 4 direction removes it — check with the council
Replacement windows and doors of similar appearance
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 1 Class A, A.3(a)
Listed buildings: 34 in the area (grade I: 0, II*: 4). The table is for houses that are not listed: on a listed building, solar panels and air source heat pumps are not permitted development at all (they need planning permission), and any of these works needs listed building consent.
Flats: 90% of the certified homes here are flats or maisonettes. Homes in a block of flats have no householder rights for alterations; heat pumps and solar have their own, tighter rules for blocks of flats.
The homes in the area (latest certificate per home, n = 1,401)
Walls
Homes
Share
Modern wall (U-value from the design)
653
46.6%
Solid wall (brick or stone), no insulation
493
35.2%
Cavity wall, insulated (as built or unspecified)
132
9.4%
Other or not known
42
3.0%
Timber frame
29
2.1%
Solid wall, insulated
17
1.2%
Solid wall, internal insulation
15
1.1%
Cavity wall, partly insulated
10
0.7%
Cavity wall, filled
3
0.2%
Cavity wall, unfilled
3
0.2%
Solid wall, external insulation
2
0.1%
Solid wall, partly insulated
2
0.1%
Heating
Homes
Share
Gas boiler
666
47.5%
Communal heating
568
40.5%
Electric (storage heaters, panels, boiler)
155
11.1%
Heat pump
11
0.8%
LPG
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
137
9.8%
Under 200 mm
83
5.9%
200 mm or more
32
2.3%
Insulated (depth not recorded)
108
7.7%
Flat or other home above
856
61.1%
Other
184
13.1%
Windows
Homes
Share
Double glazed
1,214
86.7%
Single glazed
115
8.2%
Secondary glazing
66
4.7%
Triple glazed
6
0.4%
BCD
Energy rating: B 617 (44.0%) · C 385 (27.5%) · D 305 (21.8%) · E 82 (5.9%) · F 8 (0.6%) · G 4 (0.3%). Houses and bungalows: 10% of the homes; solar panels on 0.1% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 31 August 2023.
Compared with Wandsworth and England
Share of homes
Wandsworth Town
All 47 areas in Wandsworth
England
Solid walls, no insulation
35.2%
62.1%
48.7%
Gas boiler
47.5%
81.0%
66.4%
Rated D–G
28.5%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 40% of these are from 2020 or later (latest 22 October 2026). “No insulation (assumed)” is the assessor's default for older walls.
The rules are England's national permitted development rules (General Permitted Development Order 2015, Schedule 2, as at 21 October 2026). They do not cover building regulations or a council's own conditions. This is not a planning decision: ask Wandsworth if in doubt.
Boundary: London Borough of Wandsworth via planning.data.gov.uk (entity 44001058, reference 3823, 26.1 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.