Solar panels, heat pumps and insulation in Salisbury (CA/S/44a) conservation area
In the Salisbury 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 10% of it), but the published data does not say which rights it removes — check the direction before any work. The area has 553 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. 2,081 homes inside the boundary have an energy certificate: 35.7% are solid-wall homes with no wall insulation, 62.1% heat with a gas boiler and 47.0% are rated D–G; 12 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
2,081homes with an energy certificate
35.7%solid walls, no insulation
62.1%heated by a gas boiler
12heat pumps
Article 4: An Article 4 direction published by Wiltshire covers part of this area (about 10% of it), but the published data does not say which rights it removes — check the direction before any work. (Salisbury)
What needs planning permission in Salisbury
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: 553 in the area (grade I: 32, II*: 131). 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: 60% 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 = 2,081)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
742
35.7%
Cavity wall, insulated (as built or unspecified)
400
19.2%
Modern wall (U-value from the design)
307
14.8%
Cavity wall, unfilled
203
9.8%
Cavity wall, filled
181
8.7%
Timber frame
80
3.8%
Solid wall, insulated
54
2.6%
Solid wall, internal insulation
49
2.4%
Cavity wall, partly insulated
43
2.1%
Solid wall, partly insulated
10
0.5%
Cavity wall, internal or external insulation
6
0.3%
Other or not known
4
0.2%
Solid wall, external insulation
2
0.1%
Heating
Homes
Share
Gas boiler
1,292
62.1%
Electric (storage heaters, panels, boiler)
635
30.5%
Communal heating
140
6.7%
Heat pump
12
0.6%
LPG
1
0.0%
Oil
1
0.0%
Loft / roof insulation
Homes
Share
No insulation
250
12.0%
Under 200 mm
363
17.4%
200 mm or more
404
19.4%
Insulated (depth not recorded)
249
12.0%
Flat or other home above
641
30.8%
Other
174
8.4%
Windows
Homes
Share
Double glazed
1,657
79.6%
Single glazed
267
12.8%
Secondary glazing
154
7.4%
Triple glazed
3
0.1%
BCDE
Energy rating: B 261 (12.5%) · C 841 (40.4%) · D 656 (31.5%) · E 269 (12.9%) · F 42 (2.0%) · G 12 (0.6%). Houses and bungalows: 40% of the homes; solar panels on 0.2% of the certificates. Most common build period on the certificates: before 1900. Designated: 14 February 1975.
Compared with Wiltshire and England
Share of homes
Salisbury
All 244 areas in Wiltshire
England
Solid walls, no insulation
35.7%
42.5%
48.7%
Gas boiler
62.1%
45.5%
66.4%
Rated D–G
47.0%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 59% 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 44015396, reference CA/S/44a, 251.3 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.