Solar panels, heat pumps and insulation in Soham conservation area
In the Soham conservation area (East Cambridgeshire), 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 East Cambridgeshire covers part of this area (about 9% of it) and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), painting the outside, so there these need planning permission too. The area has 39 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. 845 homes inside the boundary have an energy certificate: 37.2% are solid-wall homes with no wall insulation, 76.6% heat with a gas boiler and 50.4% are rated D–G; 5 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
845homes with an energy certificate
37.2%solid walls, no insulation
76.6%heated by a gas boiler
5heat pumps
Article 4: An Article 4 direction published by East Cambridgeshire covers part of this area (about 9% of it) and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), painting the outside, so there these need planning permission too. (1 Brook Dam Lane, Soham; 1 Townsend, Soham; 10 - 26 Evens (9) Hall Street, Soham; 11 - 13 Hall Street, Soham; 12 - 14 Evens (2) Fordham Road, Soham; 15 Speed Lane, Soham)
What needs planning permission in Soham
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
Inside the Article 4 part of the area: planning permission needed; elsewhere: no permission needed (permitted development)
Part 1 Class A, A.3(a)
Listed buildings: 39 in the area (grade I: 1, 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: 38% 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 = 845)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
314
37.2%
Cavity wall, insulated (as built or unspecified)
257
30.4%
Modern wall (U-value from the design)
146
17.3%
Solid wall, internal insulation
30
3.6%
Cavity wall, filled
28
3.3%
Timber frame
22
2.6%
Cavity wall, unfilled
13
1.5%
Solid wall, insulated
12
1.4%
Cavity wall, partly insulated
8
0.9%
Other or not known
8
0.9%
Solid wall, external insulation
5
0.6%
Cavity wall, internal or external insulation
1
0.1%
Solid wall, partly insulated
1
0.1%
Heating
Homes
Share
Gas boiler
647
76.6%
Electric (storage heaters, panels, boiler)
131
15.5%
Communal heating
51
6.0%
Oil
7
0.8%
Heat pump
5
0.6%
LPG
2
0.2%
Solid fuel (wood, coal)
2
0.2%
Loft / roof insulation
Homes
Share
No insulation
57
6.7%
Under 200 mm
166
19.6%
200 mm or more
268
31.7%
Insulated (depth not recorded)
85
10.1%
Flat or other home above
157
18.6%
Other
112
13.3%
Windows
Homes
Share
Double glazed
801
94.8%
Single glazed
40
4.7%
Other
2
0.2%
Secondary glazing
2
0.2%
BCDE
Energy rating: A 4 (0.5%) · B 154 (18.2%) · C 261 (30.9%) · D 280 (33.1%) · E 121 (14.3%) · F 20 (2.4%) · G 5 (0.6%). Houses and bungalows: 62% of the homes; solar panels on 0.5% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 January 1974.
Compared with East Cambridgeshire and England
Share of homes
Soham
All 28 areas in East Cambridgeshire
England
Solid walls, no insulation
37.2%
38.2%
48.7%
Gas boiler
76.6%
63.0%
66.4%
Rated D–G
50.4%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 51% of these are from 2020 or later (latest 26 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 East Cambridgeshire if in doubt.
Boundary: East Cambridgeshire District Council via planning.data.gov.uk (entity 44010191, reference 07/00004/CONARA, 61.4 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.