Solar panels, heat pumps and insulation in Streatham Common conservation area
In the Streatham Common conservation area (Lambeth), 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 16 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. 410 homes inside the boundary have an energy certificate: 53.9% are solid-wall homes with no wall insulation, 82.4% heat with a gas boiler and 46.6% are rated D–G; 0 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
410homes with an energy certificate
53.9%solid walls, no insulation
82.4%heated by a gas boiler
0heat pumps
Article 4: Lambeth publishes its Article 4 areas on planning.data.gov.uk and none overlaps this area; a direction can still exist on paper, so check with the council.
What needs planning permission in Streatham Common
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
No permission needed (permitted development)
Part 1 Class A, A.3(a)
Listed buildings: 16 in the area (grade I: 0, II*: 1). 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: 78% 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 = 410)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
221
53.9%
Cavity wall, unfilled
52
12.7%
Cavity wall, insulated (as built or unspecified)
48
11.7%
Modern wall (U-value from the design)
30
7.3%
Timber frame
28
6.8%
Solid wall, internal insulation
14
3.4%
Cavity wall, partly insulated
6
1.5%
Solid wall, insulated
4
1.0%
Other or not known
3
0.7%
Solid wall, partly insulated
2
0.5%
Cavity wall, filled
1
0.2%
Cavity wall, internal or external insulation
1
0.2%
Heating
Homes
Share
Gas boiler
338
82.4%
Communal heating
57
13.9%
Electric (storage heaters, panels, boiler)
15
3.7%
Loft / roof insulation
Homes
Share
No insulation
55
13.4%
Under 200 mm
40
9.8%
200 mm or more
28
6.8%
Insulated (depth not recorded)
46
11.2%
Flat or other home above
215
52.4%
Other
26
6.3%
Windows
Homes
Share
Double glazed
364
88.8%
Single glazed
35
8.5%
Secondary glazing
6
1.5%
Triple glazed
5
1.2%
CDE
Energy rating: B 23 (5.6%) · C 196 (47.8%) · D 141 (34.4%) · E 46 (11.2%) · F 3 (0.7%) · G 1 (0.2%). Houses and bungalows: 22% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 16 June 1994.
Compared with Lambeth and England
Share of homes
Streatham Common
All 65 areas in Lambeth
England
Solid walls, no insulation
53.9%
64.5%
48.7%
Gas boiler
82.4%
73.7%
66.4%
Rated D–G
46.6%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 60% of these are from 2020 or later (latest 20 August 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 Lambeth if in doubt.
Boundary: London Borough of Lambeth via planning.data.gov.uk (entity 44006855, reference CA43, 47.6 ha). Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.