Solar panels, heat pumps and insulation in Chippenham conservation area
In the Chippenham conservation area (Wiltshire), 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 Wiltshire covers part of this area (about 3% 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 229 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. 1,408 homes inside the boundary have an energy certificate: 36.6% are solid-wall homes with no wall insulation, 61.8% heat with a gas boiler and 49.9% are rated D–G; 10 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
1,408homes with an energy certificate
36.6%solid walls, no insulation
61.8%heated by a gas boiler
10heat pumps
Article 4: An Article 4 direction published by Wiltshire covers part of this area (about 3% 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. (Chippenham)
What needs planning permission in Chippenham
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: 229 in the area (grade I: 2, II*: 14). 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: 58% 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 = 1,408)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
515
36.6%
Cavity wall, insulated (as built or unspecified)
341
24.2%
Modern wall (U-value from the design)
216
15.3%
Cavity wall, unfilled
109
7.7%
Cavity wall, filled
91
6.5%
Timber frame
50
3.6%
Solid wall, internal insulation
31
2.2%
Solid wall, insulated
23
1.6%
Cavity wall, partly insulated
18
1.3%
Other or not known
11
0.8%
Cavity wall, internal or external insulation
2
0.1%
Solid wall, partly insulated
1
0.1%
Heating
Homes
Share
Gas boiler
870
61.8%
Electric (storage heaters, panels, boiler)
442
31.4%
Communal heating
78
5.5%
Heat pump
10
0.7%
Oil
5
0.4%
Other
3
0.2%
Loft / roof insulation
Homes
Share
No insulation
101
7.2%
Under 200 mm
280
19.9%
200 mm or more
294
20.9%
Insulated (depth not recorded)
166
11.8%
Flat or other home above
432
30.7%
Other
134
9.5%
Windows
Homes
Share
Double glazed
1,212
86.1%
Single glazed
117
8.3%
Secondary glazing
64
4.5%
Triple glazed
12
0.9%
Other
3
0.2%
BCDE
Energy rating: A 1 (0.1%) · B 255 (18.1%) · C 449 (31.9%) · D 456 (32.4%) · E 208 (14.8%) · F 28 (2.0%) · G 11 (0.8%). Houses and bungalows: 42% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: before 1900. Designated: 10 January 1973.
Compared with Wiltshire and England
Share of homes
Chippenham
All 244 areas in Wiltshire
England
Solid walls, no insulation
36.6%
42.5%
48.7%
Gas boiler
61.8%
45.5%
66.4%
Rated D–G
49.9%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 54% of these are from 2020 or later (latest 30 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 Wiltshire if in doubt.
Boundary: Wiltshire Council via planning.data.gov.uk (entity 44015220, reference CA/N/51, 109.3 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.