Solar panels, heat pumps and insulation in Blackheath conservation area
In the Blackheath conservation area (Lewisham), 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. An Article 4 direction published by Lewisham covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), so there these need planning permission too. The area has 136 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. 3,337 homes inside the boundary have an energy certificate: 62.7% are solid-wall homes with no wall insulation, 90.5% heat with a gas boiler and 53.7% are rated D–G; 4 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
3,337homes with an energy certificate
62.7%solid walls, no insulation
90.5%heated by a gas boiler
4heat pumps
Article 4: An Article 4 direction published by Lewisham covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), so there these need planning permission too. (48-84 Belmont Park Article 4 Direction; 52 Lee Terrace Article 4 Direction; Blackheath District Centre; Collins Street Article 4 Direction; Quentin Road Article 4 Direction; Small HMO Northern Extension)
What needs planning permission in Blackheath
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)
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)
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)
Replacement windows and doors of similar appearance
Planning permission needed (an Article 4 direction here removes this right)
Part 1 Class A, A.3(a)
Listed buildings: 136 in the area (grade I: 1, II*: 8). 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: 73% 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 = 3,337)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
2,092
62.7%
Cavity wall, insulated (as built or unspecified)
405
12.1%
Cavity wall, unfilled
314
9.4%
Modern wall (U-value from the design)
113
3.4%
Other or not known
113
3.4%
Cavity wall, filled
88
2.6%
Cavity wall, partly insulated
87
2.6%
Timber frame
56
1.7%
Solid wall, internal insulation
36
1.1%
Solid wall, partly insulated
13
0.4%
Solid wall, insulated
12
0.4%
Solid wall, external insulation
5
0.1%
Cavity wall, internal or external insulation
3
0.1%
Heating
Homes
Share
Gas boiler
3,019
90.5%
Communal heating
165
4.9%
Electric (storage heaters, panels, boiler)
147
4.4%
Heat pump
4
0.1%
LPG
1
0.0%
Solid fuel (wood, coal)
1
0.0%
Loft / roof insulation
Homes
Share
No insulation
451
13.5%
Under 200 mm
503
15.1%
200 mm or more
312
9.3%
Insulated (depth not recorded)
366
11.0%
Flat or other home above
1,617
48.5%
Other
88
2.6%
Windows
Homes
Share
Double glazed
2,296
68.8%
Single glazed
934
28.0%
Secondary glazing
96
2.9%
Triple glazed
11
0.3%
CDE
Energy rating: A 1 (0.0%) · B 88 (2.6%) · C 1,455 (43.6%) · D 1,340 (40.2%) · E 383 (11.5%) · F 57 (1.7%) · G 13 (0.4%). Houses and bungalows: 27% of the homes; solar panels on 0.1% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 January 1968.
Compared with Lewisham and England
Share of homes
Blackheath
All 31 areas in Lewisham
England
Solid walls, no insulation
62.7%
69.0%
48.7%
Gas boiler
90.5%
85.5%
66.4%
Rated D–G
53.7%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 61% of these are from 2020 or later (latest 31 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 Lewisham if in doubt.
Boundary: London Borough of Lewisham via planning.data.gov.uk (entity 44015156, reference LEWCA1, 182.2 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.