Solar panels, heat pumps and insulation in Longbrook conservation area
In the Longbrook conservation area (Exeter), 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 Exeter covers this area but deals with other things (such as changes of use); it does not change the rules below. The area has 24 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. 1,121 homes inside the boundary have an energy certificate: 37.4% are solid-wall homes with no wall insulation, 69.3% heat with a gas boiler and 50.6% 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
1,121homes with an energy certificate
37.4%solid walls, no insulation
69.3%heated by a gas boiler
0heat pumps
Article 4: An Article 4 direction published by Exeter covers this area but deals with other things (such as changes of use); it does not change the rules below. (2023 Article 4 Direction)
What needs planning permission in Longbrook
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: 24 in the area (grade I: 0, II*: 1). 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: 56% 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 = 1,121)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
419
37.4%
Cavity wall, insulated (as built or unspecified)
221
19.7%
Cavity wall, unfilled
198
17.7%
Cavity wall, filled
72
6.4%
Timber frame
49
4.4%
Other or not known
45
4.0%
Modern wall (U-value from the design)
39
3.5%
Solid wall, internal insulation
26
2.3%
Solid wall, insulated
21
1.9%
Cavity wall, internal or external insulation
15
1.3%
Cavity wall, partly insulated
11
1.0%
Solid wall, partly insulated
5
0.4%
Heating
Homes
Share
Gas boiler
777
69.3%
Electric (storage heaters, panels, boiler)
234
20.9%
Communal heating
108
9.6%
LPG
1
0.1%
Solid fuel (wood, coal)
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
140
12.5%
Under 200 mm
188
16.8%
200 mm or more
253
22.6%
Insulated (depth not recorded)
126
11.2%
Flat or other home above
393
35.1%
Other
21
1.9%
Windows
Homes
Share
Double glazed
1,001
89.4%
Single glazed
95
8.5%
Secondary glazing
24
2.1%
CDE
Energy rating: B 78 (7.0%) · C 476 (42.5%) · D 423 (37.7%) · E 129 (11.5%) · F 8 (0.7%) · G 7 (0.6%). Houses and bungalows: 44% of the homes; solar panels on 1.3% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 22 March 1993.
Compared with Exeter and England
Share of homes
Longbrook
All 20 areas in Exeter
England
Solid walls, no insulation
37.4%
35.2%
48.7%
Gas boiler
69.3%
69.4%
66.4%
Rated D–G
50.6%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 60% 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 Exeter if in doubt.
Boundary: Exeter City Council via planning.data.gov.uk (entity 44015009, reference CA08, 34.0 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.