Solar panels, heat pumps and insulation in Farnham conservation area
In the Farnham conservation area (Waverley), 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 Waverley covers part of this area (about 0% 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), so there these need planning permission too. The area has 246 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. 815 homes inside the boundary have an energy certificate: 40.0% are solid-wall homes with no wall insulation, 71.3% heat with a gas boiler and 59.6% are rated D–G; 14 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
815homes with an energy certificate
40.0%solid walls, no insulation
71.3%heated by a gas boiler
14heat pumps
Article 4: An Article 4 direction published by Waverley covers part of this area (about 0% 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), so there these need planning permission too. (Long Garden Walk, Farnham (2006); Lowndes Buildings, Castle Street, Farnham (2006))
What needs planning permission in Farnham
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: 246 in the area (grade I: 4, II*: 37). 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: 46% 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 = 815)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
326
40.0%
Modern wall (U-value from the design)
167
20.5%
Cavity wall, insulated (as built or unspecified)
108
13.3%
Cavity wall, filled
54
6.6%
Cavity wall, unfilled
46
5.6%
Timber frame
40
4.9%
Solid wall, insulated
21
2.6%
Solid wall, internal insulation
21
2.6%
Cavity wall, partly insulated
15
1.8%
Other or not known
10
1.2%
Cavity wall, internal or external insulation
4
0.5%
Solid wall, partly insulated
2
0.2%
Solid wall, external insulation
1
0.1%
Heating
Homes
Share
Gas boiler
581
71.3%
Electric (storage heaters, panels, boiler)
160
19.6%
Communal heating
58
7.1%
Heat pump
14
1.7%
Solid fuel (wood, coal)
2
0.2%
Loft / roof insulation
Homes
Share
No insulation
92
11.3%
Under 200 mm
193
23.7%
200 mm or more
159
19.5%
Insulated (depth not recorded)
111
13.6%
Flat or other home above
139
17.1%
Other
120
14.7%
Windows
Homes
Share
Double glazed
580
71.2%
Single glazed
159
19.5%
Secondary glazing
74
9.1%
Triple glazed
2
0.2%
CDE
Energy rating: A 1 (0.1%) · B 47 (5.8%) · C 281 (34.5%) · D 333 (40.9%) · E 123 (15.1%) · F 21 (2.6%) · G 9 (1.1%). Houses and bungalows: 54% of the homes; solar panels on 0.7% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 January 1970.
Compared with Waverley and England
Share of homes
Farnham
All 44 areas in Waverley
England
Solid walls, no insulation
40.0%
37.8%
48.7%
Gas boiler
71.3%
74.3%
66.4%
Rated D–G
59.6%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 56% of these are from 2020 or later (latest 28 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 Waverley if in doubt.
Boundary: Waverley Borough Council via planning.data.gov.uk (entity 44014271, reference P31/3/9, 50.6 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.