Solar panels, heat pumps and insulation in City Centre conservation area
In the City Centre conservation area (Norwich), 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 729 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. 6,445 homes inside the boundary have an energy certificate: 22.2% are solid-wall homes with no wall insulation, 53.5% heat with a gas boiler and 35.5% are rated D–G; 74 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
6,445homes with an energy certificate
22.2%solid walls, no insulation
53.5%heated by a gas boiler
74heat pumps
Article 4: Norwich does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in City Centre
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: 729 in the area (grade I: 59, II*: 111). 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: 78% 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 = 6,445)
Walls
Homes
Share
Cavity wall, insulated (as built or unspecified)
1,615
25.1%
Solid wall (brick or stone), no insulation
1,432
22.2%
Modern wall (U-value from the design)
1,384
21.5%
Cavity wall, filled
798
12.4%
Other or not known
486
7.5%
Cavity wall, partly insulated
186
2.9%
Cavity wall, unfilled
186
2.9%
Timber frame
184
2.9%
Solid wall, insulated
90
1.4%
Solid wall, internal insulation
58
0.9%
Cavity wall, internal or external insulation
12
0.2%
Solid wall, partly insulated
10
0.2%
Solid wall, external insulation
4
0.1%
Heating
Homes
Share
Gas boiler
3,450
53.5%
Electric (storage heaters, panels, boiler)
2,346
36.4%
Communal heating
528
8.2%
Heat pump
74
1.1%
Oil
36
0.6%
Other
5
0.1%
LPG
3
0.0%
Solid fuel (wood, coal)
3
0.0%
Loft / roof insulation
Homes
Share
No insulation
272
4.2%
Under 200 mm
746
11.6%
200 mm or more
1,032
16.0%
Insulated (depth not recorded)
703
10.9%
Flat or other home above
3,079
47.8%
Other
612
9.5%
Windows
Homes
Share
Double glazed
5,510
85.5%
Single glazed
598
9.3%
Secondary glazing
321
5.0%
Triple glazed
12
0.2%
Other
4
0.1%
BCD
Energy rating: A 4 (0.1%) · B 983 (15.3%) · C 3,167 (49.1%) · D 1,756 (27.2%) · E 471 (7.3%) · F 47 (0.7%) · G 17 (0.3%). Houses and bungalows: 22% of the homes; solar panels on 0.2% of the certificates. Most common build period on the certificates: before 1900.
Compared with Norwich and England
Share of homes
City Centre
All 17 areas in Norwich
England
Solid walls, no insulation
22.2%
28.4%
48.7%
Gas boiler
53.5%
64.3%
66.4%
Rated D–G
35.5%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 50% of these are from 2020 or later (latest 29 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 Norwich if in doubt.
Boundary: Norwich City Council via planning.data.gov.uk (entity 44014297, reference 8, 231.8 ha). Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.