Solar panels, heat pumps and insulation in Ashley Down conservation area
In the Ashley Down conservation area (Bristol), 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 Bristol covers this area but deals with other things (such as changes of use); it does not change the rules below. The area has 6 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. 393 homes inside the boundary have an energy certificate: 3.6% are solid-wall homes with no wall insulation, 63.9% heat with a gas boiler and 26.5% are rated D–G; 0 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
393homes with an energy certificate
3.6%solid walls, no insulation
63.9%heated by a gas boiler
0heat pumps
Article 4: An Article 4 direction published by Bristol covers this area but deals with other things (such as changes of use); it does not change the rules below. (Article 4 North)
What needs planning permission in Ashley Down
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
No permission needed (permitted development)
Part 1 Class A, A.3(a)
Listed buildings: 6 in the area. 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: 69% 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 = 393)
Walls
Homes
Share
Cavity wall, insulated (as built or unspecified)
177
45.0%
Modern wall (U-value from the design)
121
30.8%
Solid wall, insulated
37
9.4%
Solid wall, internal insulation
22
5.6%
Solid wall (brick or stone), no insulation
14
3.6%
Timber frame
10
2.5%
Other or not known
8
2.0%
Solid wall, partly insulated
3
0.8%
Cavity wall, unfilled
1
0.3%
Heating
Homes
Share
Gas boiler
251
63.9%
Electric (storage heaters, panels, boiler)
116
29.5%
Communal heating
26
6.6%
Loft / roof insulation
Homes
Share
No insulation
2
0.5%
Under 200 mm
12
3.1%
200 mm or more
43
10.9%
Insulated (depth not recorded)
102
26.0%
Flat or other home above
157
39.9%
Other
77
19.6%
Windows
Homes
Share
Double glazed
332
84.5%
Single glazed
46
11.7%
Secondary glazing
14
3.6%
Triple glazed
1
0.3%
BCD
Energy rating: B 117 (29.8%) · C 172 (43.8%) · D 70 (17.8%) · E 30 (7.6%) · F 3 (0.8%) · G 1 (0.3%). Houses and bungalows: 31% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: 2003-2006. Designated: 10 June 1998.
Compared with Bristol and England
Share of homes
Ashley Down
All 34 areas in Bristol
England
Solid walls, no insulation
3.6%
43.8%
48.7%
Gas boiler
63.9%
62.5%
66.4%
Rated D–G
26.5%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 53% of these are from 2020 or later (latest 13 September 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 Bristol if in doubt.
Boundary: Bristol City Council via planning.data.gov.uk (entity 44010618, reference CA31, 17.0 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.