Solar panels, heat pumps and insulation in Stonehouse Peninsula conservation area
In the Stonehouse Peninsula 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 65 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. 885 homes inside the boundary have an energy certificate: 41.5% are solid-wall homes with no wall insulation, 62.0% heat with a gas boiler and 40.1% 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
885homes with an energy certificate
41.5%solid walls, no insulation
62.0%heated by a gas boiler
1heat 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 Stonehouse Peninsula
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: 65 in the area (grade I: 10, II*: 13). 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: 83% 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 = 885)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
367
41.5%
Solid wall, insulated
128
14.5%
Cavity wall, insulated (as built or unspecified)
87
9.8%
Modern wall (U-value from the design)
72
8.1%
Cavity wall, unfilled
65
7.3%
Cavity wall, filled
62
7.0%
Other or not known
55
6.2%
Timber frame
25
2.8%
Solid wall, internal insulation
12
1.4%
Cavity wall, partly insulated
8
0.9%
Solid wall, partly insulated
2
0.2%
Cavity wall, internal or external insulation
1
0.1%
Solid wall, external insulation
1
0.1%
Heating
Homes
Share
Gas boiler
549
62.0%
Communal heating
227
25.6%
Electric (storage heaters, panels, boiler)
105
11.9%
Solid fuel (wood, coal)
2
0.2%
Heat pump
1
0.1%
LPG
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
82
9.3%
Under 200 mm
79
8.9%
200 mm or more
100
11.3%
Insulated (depth not recorded)
119
13.4%
Flat or other home above
451
51.0%
Other
54
6.1%
Windows
Homes
Share
Double glazed
670
75.7%
Single glazed
207
23.4%
Secondary glazing
7
0.8%
Triple glazed
1
0.1%
BCDE
Energy rating: B 82 (9.3%) · C 448 (50.6%) · D 251 (28.4%) · E 87 (9.8%) · F 13 (1.5%) · G 4 (0.5%). Houses and bungalows: 17% 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
Stonehouse Peninsula
All 16 areas in Plymouth
England
Solid walls, no insulation
41.5%
44.9%
48.7%
Gas boiler
62.0%
69.8%
66.4%
Rated D–G
40.1%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 49% 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 Plymouth if in doubt.
Boundary: Plymouth City Council via planning.data.gov.uk (entity 44012315, reference CON05, 41.9 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.