Solar panels, heat pumps and insulation in Dorking conservation area
In the Dorking conservation area (Mole Valley), 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 120 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. 1,357 homes inside the boundary have an energy certificate: 43.9% are solid-wall homes with no wall insulation, 68.2% heat with a gas boiler and 57.8% are rated D–G; 13 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
1,357homes with an energy certificate
43.9%solid walls, no insulation
68.2%heated by a gas boiler
13heat pumps
Article 4: Mole Valley does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Dorking
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: 120 in the area (grade I: 0, II*: 2). 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: 54% 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 = 1,357)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
596
43.9%
Modern wall (U-value from the design)
262
19.3%
Cavity wall, insulated (as built or unspecified)
121
8.9%
Timber frame
100
7.4%
Cavity wall, filled
98
7.2%
Cavity wall, unfilled
87
6.4%
Solid wall, insulated
28
2.1%
Solid wall, internal insulation
22
1.6%
Other or not known
19
1.4%
Cavity wall, partly insulated
11
0.8%
Solid wall, external insulation
9
0.7%
Solid wall, partly insulated
3
0.2%
Cavity wall, internal or external insulation
1
0.1%
Heating
Homes
Share
Gas boiler
926
68.2%
Electric (storage heaters, panels, boiler)
342
25.2%
Communal heating
72
5.3%
Heat pump
13
1.0%
Oil
2
0.1%
LPG
1
0.1%
Solid fuel (wood, coal)
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
190
14.0%
Under 200 mm
300
22.1%
200 mm or more
190
14.0%
Insulated (depth not recorded)
163
12.0%
Flat or other home above
313
23.1%
Other
201
14.8%
Windows
Homes
Share
Double glazed
1,156
85.2%
Single glazed
146
10.8%
Secondary glazing
53
3.9%
Triple glazed
2
0.1%
CDE
Energy rating: A 2 (0.1%) · B 96 (7.1%) · C 475 (35.0%) · D 496 (36.6%) · E 240 (17.7%) · F 32 (2.4%) · G 16 (1.2%). Houses and bungalows: 46% of the homes; solar panels on 0.4% of the certificates. Most common build period on the certificates: before 1900. Designated: 24 March 1974.
Compared with Mole Valley and England
Share of homes
Dorking
All 37 areas in Mole Valley
England
Solid walls, no insulation
43.9%
42.9%
48.7%
Gas boiler
68.2%
77.6%
66.4%
Rated D–G
57.8%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 54% 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 Mole Valley if in doubt.
Boundary: Mole Valley District Council via planning.data.gov.uk (entity 44004251, reference 2730, 46.9 ha). Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.