Solar panels, heat pumps and insulation in The Spa conservation area
In the The Spa conservation area (Gloucester), 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 Gloucester 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), painting the outside, so there these need planning permission too. The area has 41 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. 658 homes inside the boundary have an energy certificate: 55.3% are solid-wall homes with no wall insulation, 67.8% heat with a gas boiler and 49.1% 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
658homes with an energy certificate
55.3%solid walls, no insulation
67.8%heated by a gas boiler
12heat pumps
Article 4: An Article 4 direction published by Gloucester 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), painting the outside, so there these need planning permission too. (St Michael’s Square Article 4 direction)
What needs planning permission in The Spa
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: 41 in the area (grade I: 0, II*: 2). 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: 83% 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 = 658)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
364
55.3%
Modern wall (U-value from the design)
95
14.4%
Cavity wall, insulated (as built or unspecified)
83
12.6%
Timber frame
46
7.0%
Other or not known
20
3.0%
Cavity wall, filled
16
2.4%
Solid wall, internal insulation
10
1.5%
Cavity wall, unfilled
8
1.2%
Solid wall, insulated
7
1.1%
Cavity wall, partly insulated
5
0.8%
Solid wall, partly insulated
4
0.6%
Heating
Homes
Share
Gas boiler
446
67.8%
Electric (storage heaters, panels, boiler)
179
27.2%
Communal heating
20
3.0%
Heat pump
12
1.8%
LPG
1
0.2%
Loft / roof insulation
Homes
Share
No insulation
57
8.7%
Under 200 mm
69
10.5%
200 mm or more
58
8.8%
Insulated (depth not recorded)
68
10.3%
Flat or other home above
363
55.2%
Other
43
6.5%
Windows
Homes
Share
Double glazed
497
75.5%
Single glazed
144
21.9%
Secondary glazing
16
2.4%
Triple glazed
1
0.2%
CDE
Energy rating: B 42 (6.4%) · C 293 (44.5%) · D 217 (33.0%) · E 93 (14.1%) · F 10 (1.5%) · G 3 (0.5%). Houses and bungalows: 17% of the homes; solar panels on 0.2% of the certificates. Most common build period on the certificates: before 1900. Designated: 6 March 1968.
Compared with Gloucester and England
Share of homes
The Spa
All 14 areas in Gloucester
England
Solid walls, no insulation
55.3%
44.0%
48.7%
Gas boiler
67.8%
54.1%
66.4%
Rated D–G
49.1%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 61% 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 Gloucester if in doubt.
Boundary: Gloucester City Council via planning.data.gov.uk (entity 44009672, reference 9, 27.8 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.