Solar panels, heat pumps and insulation in Durham City conservation area
In the Durham City conservation area (Durham), 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 435 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. 3,583 homes inside the boundary have an energy certificate: 32.1% are solid-wall homes with no wall insulation, 78.3% heat with a gas boiler and 45.5% are rated D–G; 13 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
3,583homes with an energy certificate
32.1%solid walls, no insulation
78.3%heated by a gas boiler
13heat pumps
Article 4: Durham does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Durham City
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: 435 in the area (grade I: 43, II*: 25). 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: 42% 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 = 3,583)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
1,150
32.1%
Cavity wall, filled
645
18.0%
Cavity wall, insulated (as built or unspecified)
628
17.5%
Cavity wall, unfilled
489
13.6%
Modern wall (U-value from the design)
389
10.9%
Timber frame
62
1.7%
Solid wall, internal insulation
58
1.6%
Solid wall, insulated
57
1.6%
Other or not known
47
1.3%
Cavity wall, partly insulated
42
1.2%
Solid wall, partly insulated
9
0.3%
Cavity wall, internal or external insulation
6
0.2%
Solid wall, external insulation
1
0.0%
Heating
Homes
Share
Gas boiler
2,807
78.3%
Electric (storage heaters, panels, boiler)
711
19.8%
Communal heating
46
1.3%
Heat pump
13
0.4%
Oil
4
0.1%
Solid fuel (wood, coal)
2
0.1%
Loft / roof insulation
Homes
Share
No insulation
481
13.4%
Under 200 mm
543
15.2%
200 mm or more
1,035
28.9%
Insulated (depth not recorded)
433
12.1%
Flat or other home above
885
24.7%
Other
206
5.7%
Windows
Homes
Share
Double glazed
3,208
89.5%
Single glazed
268
7.5%
Secondary glazing
103
2.9%
Triple glazed
4
0.1%
BCDE
Energy rating: A 3 (0.1%) · B 410 (11.4%) · C 1,538 (42.9%) · D 1,251 (34.9%) · E 339 (9.5%) · F 36 (1.0%) · G 6 (0.2%). Houses and bungalows: 58% of the homes; solar panels on 0.8% of the certificates. Most common build period on the certificates: before 1900. Designated: 9 August 1968.
Compared with Durham and England
Share of homes
Durham City
All 93 areas in Durham
England
Solid walls, no insulation
32.1%
47.6%
48.7%
Gas boiler
78.3%
72.9%
66.4%
Rated D–G
45.5%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 54% 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 Durham if in doubt.
Boundary: Durham County Council via planning.data.gov.uk (entity 44000432, reference 6077, 421.5 ha). Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.