Solar panels, heat pumps and insulation in Soho conservation area
In the Soho conservation area (Westminster), 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 Westminster covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, so there these need planning permission too. The area has 218 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. 2,002 homes inside the boundary have an energy certificate: 44.4% are solid-wall homes with no wall insulation, 38.1% heat with a gas boiler and 30.2% are rated D–G; 129 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
2,002homes with an energy certificate
44.4%solid walls, no insulation
38.1%heated by a gas boiler
129heat pumps
Article 4: An Article 4 direction published by Westminster covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, so there these need planning permission too. (Article 4 Basement Development Permitted Rights Removed; Article 4 Direction Class E To C3 In Central Activities Zone)
What needs planning permission in Soho
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: 218 in the area (grade I: 2, II*: 20). 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: 99% 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 = 2,002)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
888
44.4%
Modern wall (U-value from the design)
360
18.0%
Cavity wall, insulated (as built or unspecified)
226
11.3%
Other or not known
225
11.2%
Solid wall, internal insulation
87
4.3%
Timber frame
80
4.0%
Cavity wall, unfilled
47
2.3%
Solid wall, insulated
43
2.1%
Solid wall, partly insulated
23
1.1%
Cavity wall, partly insulated
17
0.8%
Cavity wall, internal or external insulation
5
0.2%
Cavity wall, filled
1
0.0%
Heating
Homes
Share
Gas boiler
763
38.1%
Communal heating
649
32.4%
Electric (storage heaters, panels, boiler)
460
23.0%
Heat pump
129
6.4%
LPG
1
0.0%
Loft / roof insulation
Homes
Share
No insulation
177
8.8%
Under 200 mm
54
2.7%
200 mm or more
22
1.1%
Insulated (depth not recorded)
227
11.3%
Flat or other home above
1,365
68.2%
Other
157
7.8%
Windows
Homes
Share
Double glazed
1,257
62.8%
Secondary glazing
419
20.9%
Single glazed
308
15.4%
Triple glazed
18
0.9%
BCD
Energy rating: B 384 (19.2%) · C 1,013 (50.6%) · D 422 (21.1%) · E 154 (7.7%) · F 19 (0.9%) · G 10 (0.5%). Houses and bungalows: 1% of the homes; solar panels on 0.1% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 1 January 1990.
Compared with Westminster and England
Share of homes
Soho
All 56 areas in Westminster
England
Solid walls, no insulation
44.4%
66.4%
48.7%
Gas boiler
38.1%
59.2%
66.4%
Rated D–G
30.2%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 65% of these are from 2020 or later (latest 29 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 Westminster if in doubt.
Boundary: City of Westminster via planning.data.gov.uk (entity 44002896, reference 08/01230/CONARA, 34.6 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.