Solar panels, heat pumps and insulation in North Stonehouse conservation area
In the North Stonehouse conservation area (Plymouth), 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 Plymouth covers this area but deals with other things (such as changes of use); it does not change the rules below. The area has 12 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. 944 homes inside the boundary have an energy certificate: 66.1% are solid-wall homes with no wall insulation, 81.4% heat with a gas boiler and 49.7% 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
944homes with an energy certificate
66.1%solid walls, no insulation
81.4%heated by a gas boiler
0heat pumps
Article 4: An Article 4 direction published by Plymouth covers this area but deals with other things (such as changes of use); it does not change the rules below. (HMOs Mutley, Greenbank, City Centre and surrounding areas)
What needs planning permission in North Stonehouse
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: 12 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: 76% 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 = 944)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
624
66.1%
Cavity wall, insulated (as built or unspecified)
159
16.8%
Modern wall (U-value from the design)
34
3.6%
Solid wall, internal insulation
26
2.8%
Cavity wall, unfilled
22
2.3%
Cavity wall, filled
19
2.0%
Solid wall, external insulation
17
1.8%
Solid wall, insulated
14
1.5%
Timber frame
14
1.5%
Cavity wall, partly insulated
10
1.1%
Solid wall, partly insulated
5
0.5%
Heating
Homes
Share
Gas boiler
768
81.4%
Electric (storage heaters, panels, boiler)
156
16.5%
Communal heating
19
2.0%
LPG
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
106
11.2%
Under 200 mm
180
19.1%
200 mm or more
168
17.8%
Insulated (depth not recorded)
52
5.5%
Flat or other home above
423
44.8%
Other
15
1.6%
Windows
Homes
Share
Double glazed
824
87.3%
Single glazed
91
9.6%
Secondary glazing
29
3.1%
CDE
Energy rating: B 60 (6.4%) · C 415 (44.0%) · D 352 (37.3%) · E 102 (10.8%) · F 10 (1.1%) · G 5 (0.5%). Houses and bungalows: 24% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: before 1900. Designated: 19 October 2006.
Compared with Plymouth and England
Share of homes
North Stonehouse
All 16 areas in Plymouth
England
Solid walls, no insulation
66.1%
44.9%
48.7%
Gas boiler
81.4%
69.8%
66.4%
Rated D–G
49.7%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 62% 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 Plymouth if in doubt.
Boundary: Plymouth City Council via planning.data.gov.uk (entity 44012314, reference CON07, 14.1 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.