Solar panels, heat pumps and insulation in Telford Park conservation area
In the Telford Park 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. 444 homes inside the boundary have an energy certificate: 84.7% are solid-wall homes with no wall insulation, 88.7% heat with a gas boiler and 72.1% 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
444homes with an energy certificate
84.7%solid walls, no insulation
88.7%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 Telford Park
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: none recorded inside the boundary; on a listed building, solar panels and heat pumps are not permitted development and need listed building consent.
Flats: 72% 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 = 444)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
376
84.7%
Timber frame
24
5.4%
Solid wall, internal insulation
12
2.7%
Cavity wall, unfilled
11
2.5%
Cavity wall, insulated (as built or unspecified)
9
2.0%
Cavity wall, partly insulated
5
1.1%
Solid wall, insulated
3
0.7%
Solid wall, partly insulated
3
0.7%
Modern wall (U-value from the design)
1
0.2%
Heating
Homes
Share
Gas boiler
394
88.7%
Communal heating
34
7.7%
Electric (storage heaters, panels, boiler)
15
3.4%
LPG
1
0.2%
Loft / roof insulation
Homes
Share
No insulation
84
18.9%
Under 200 mm
70
15.8%
200 mm or more
21
4.7%
Insulated (depth not recorded)
45
10.1%
Flat or other home above
218
49.1%
Other
6
1.4%
Windows
Homes
Share
Double glazed
330
74.3%
Single glazed
110
24.8%
Secondary glazing
3
0.7%
Triple glazed
1
0.2%
CDE
Energy rating: B 1 (0.2%) · C 123 (27.7%) · D 215 (48.4%) · E 84 (18.9%) · F 18 (4.1%) · G 3 (0.7%). Houses and bungalows: 28% of the homes; solar panels on 0.2% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 9 September 1994.
Compared with Lambeth and England
Share of homes
Telford Park
All 65 areas in Lambeth
England
Solid walls, no insulation
84.7%
64.5%
48.7%
Gas boiler
88.7%
73.7%
66.4%
Rated D–G
72.1%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 51% of these are from 2020 or later (latest 17 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 Lambeth if in doubt.
Boundary: London Borough of Lambeth via planning.data.gov.uk (entity 44000885, reference CA44, 14.4 ha). Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.