Solar panels, heat pumps and insulation in Bath conservation area
In the Bath conservation area (Bath and North East Somerset), 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 2246 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. 16,898 homes inside the boundary have an energy certificate: 53.0% are solid-wall homes with no wall insulation, 73.3% heat with a gas boiler and 61.6% are rated D–G; 102 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
16,898homes with an energy certificate
53.0%solid walls, no insulation
73.3%heated by a gas boiler
102heat pumps
Article 4: Bath and North East Somerset does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Bath
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: 2246 in the area (grade I: 103, II*: 116). 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 = 16,898)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
8,959
53.0%
Cavity wall, filled
2,439
14.4%
Cavity wall, unfilled
1,529
9.0%
Cavity wall, insulated (as built or unspecified)
1,276
7.6%
Modern wall (U-value from the design)
1,193
7.1%
Timber frame
733
4.3%
Cavity wall, partly insulated
218
1.3%
Solid wall, internal insulation
214
1.3%
Solid wall, insulated
182
1.1%
Other or not known
78
0.5%
Solid wall, partly insulated
44
0.3%
Cavity wall, internal or external insulation
25
0.1%
Solid wall, external insulation
7
0.0%
Heating
Homes
Share
Gas boiler
12,386
73.3%
Electric (storage heaters, panels, boiler)
3,675
21.7%
Communal heating
685
4.1%
Heat pump
102
0.6%
Oil
25
0.1%
LPG
17
0.1%
Solid fuel (wood, coal)
8
0.0%
Loft / roof insulation
Homes
Share
No insulation
1,399
8.3%
Under 200 mm
3,488
20.6%
200 mm or more
3,103
18.4%
Insulated (depth not recorded)
1,595
9.4%
Flat or other home above
6,518
38.6%
Other
793
4.7%
Windows
Homes
Share
Double glazed
10,805
63.9%
Single glazed
5,139
30.4%
Secondary glazing
902
5.3%
Triple glazed
50
0.3%
Other
2
0.0%
CDE
Energy rating: A 39 (0.2%) · B 1,045 (6.2%) · C 5,413 (32.0%) · D 6,765 (40.0%) · E 3,065 (18.1%) · F 475 (2.8%) · G 96 (0.6%). Houses and bungalows: 42% of the homes; solar panels on 0.5% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 January 1968.
Compared with Bath and North East Somerset and England
Share of homes
Bath
All 35 areas in Bath and North East Somerset
England
Solid walls, no insulation
53.0%
53.0%
48.7%
Gas boiler
73.3%
73.5%
66.4%
Rated D–G
61.6%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 57% of these are from 2020 or later (latest 31 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 Bath and North East Somerset if in doubt.
Boundary: Bath and North East Somerset Council via planning.data.gov.uk (entity 44006636, reference 5113, 1,488.8 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.