Solar panels, heat pumps and insulation in Heaton Mersey conservation area
In the Heaton Mersey conservation area (Stockport), 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 Stockport covers part of this area (about 27% 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), chimneys, flues and soil pipes, painting the outside, so there these need planning permission too. The area has 8 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. 382 homes inside the boundary have an energy certificate: 57.1% are solid-wall homes with no wall insulation, 96.3% heat with a gas boiler and 68.8% are rated D–G; 1 has 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
382homes with an energy certificate
57.1%solid walls, no insulation
96.3%heated by a gas boiler
1heat pumps
Article 4: An Article 4 direction published by Stockport covers part of this area (about 27% 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), chimneys, flues and soil pipes, painting the outside, so there these need planning permission too. (Heaton Mersey)
What needs planning permission in Heaton Mersey
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: 8 in the area. 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: 25% 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 = 382)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
218
57.1%
Cavity wall, filled
51
13.4%
Cavity wall, insulated (as built or unspecified)
47
12.3%
Cavity wall, unfilled
42
11.0%
Cavity wall, partly insulated
9
2.4%
Timber frame
5
1.3%
Other or not known
4
1.0%
Solid wall, internal insulation
3
0.8%
Modern wall (U-value from the design)
1
0.3%
Solid wall, external insulation
1
0.3%
Solid wall, insulated
1
0.3%
Heating
Homes
Share
Gas boiler
368
96.3%
Electric (storage heaters, panels, boiler)
12
3.1%
Heat pump
1
0.3%
Oil
1
0.3%
Loft / roof insulation
Homes
Share
No insulation
92
24.1%
Under 200 mm
122
31.9%
200 mm or more
94
24.6%
Insulated (depth not recorded)
23
6.0%
Flat or other home above
50
13.1%
Other
1
0.3%
Windows
Homes
Share
Double glazed
337
88.2%
Single glazed
43
11.3%
Secondary glazing
1
0.3%
Triple glazed
1
0.3%
CDE
Energy rating: B 6 (1.6%) · C 113 (29.6%) · D 186 (48.7%) · E 72 (18.8%) · F 4 (1.0%) · G 1 (0.3%). Houses and bungalows: 75% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 1 January 1978.
Compared with Stockport and England
Share of homes
Heaton Mersey
All 37 areas in Stockport
England
Solid walls, no insulation
57.1%
30.6%
48.7%
Gas boiler
96.3%
73.3%
66.4%
Rated D–G
68.8%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 48% of these are from 2020 or later (latest 22 August 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 Stockport if in doubt.
Boundary: Stockport Metropolitan Borough Council via planning.data.gov.uk (entity 44014596, reference 13, 25.7 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.