Solar panels, heat pumps and insulation in Thomas A'Becket and High Street conservation area
In the Thomas A'Becket and High Street conservation area (Southwark), 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 Southwark covers this area, but the published data does not say which rights it removes — check the direction before any work. The area has 5 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. 712 homes inside the boundary have an energy certificate: 68.8% are solid-wall homes with no wall insulation, 74.0% heat with a gas boiler and 39.7% 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
712homes with an energy certificate
68.8%solid walls, no insulation
74.0%heated by a gas boiler
0heat pumps
Article 4: An Article 4 direction published by Southwark covers this area, but the published data does not say which rights it removes — check the direction before any work. (Old Kent Road North District Town Centre; Protected shopping frontage SF24: Old Kent Road, East Street and Dunton Road; Site allocation NSP56: Bricklayers Arms; Site allocation NSP58: Mandela Way; Site allocation NSP62: Former petrol filling station, 233-247 Old Kent Road; Site allocation NSP63: Kinglake Street Garages)
What needs planning permission in Thomas A'Becket and High Street
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: 5 in the area. 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 = 712)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
490
68.8%
Modern wall (U-value from the design)
87
12.2%
Cavity wall, insulated (as built or unspecified)
51
7.2%
Solid wall, internal insulation
21
2.9%
Timber frame
17
2.4%
Cavity wall, partly insulated
11
1.5%
Cavity wall, unfilled
11
1.5%
Cavity wall, filled
10
1.4%
Other or not known
4
0.6%
Solid wall, external insulation
4
0.6%
Solid wall, insulated
4
0.6%
Cavity wall, internal or external insulation
2
0.3%
Heating
Homes
Share
Gas boiler
527
74.0%
Electric (storage heaters, panels, boiler)
103
14.5%
Communal heating
82
11.5%
Loft / roof insulation
Homes
Share
No insulation
101
14.2%
Under 200 mm
63
8.8%
200 mm or more
29
4.1%
Insulated (depth not recorded)
52
7.3%
Flat or other home above
433
60.8%
Other
34
4.8%
Windows
Homes
Share
Double glazed
632
88.8%
Single glazed
55
7.7%
Secondary glazing
15
2.1%
Triple glazed
10
1.4%
BCD
Energy rating: A 4 (0.6%) · B 69 (9.7%) · C 356 (50.0%) · D 220 (30.9%) · E 55 (7.7%) · F 3 (0.4%) · G 5 (0.7%). Houses and bungalows: 10% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: 1900-1929.
Compared with Southwark and England
Share of homes
Thomas A'Becket and High Street
All 56 areas in Southwark
England
Solid walls, no insulation
68.8%
56.7%
48.7%
Gas boiler
74.0%
71.3%
66.4%
Rated D–G
39.7%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 62% of these are from 2020 or later (latest 8 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 Southwark if in doubt.
Boundary: London Borough of Southwark via planning.data.gov.uk (entity 44010266, reference 50, 8.6 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.