Solar panels, heat pumps and insulation in Isles of Scilly (council-of-the-isles-of-scilly-conservation-area-1) conservation area
In the Isles of Scilly conservation area (Council of the Isles of Scilly), 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 Council of the Isles of Scilly covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), painting the outside, so there these need planning permission too. The area has 100 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. 677 homes inside the boundary have an energy certificate: 25.6% are solid-wall homes with no wall insulation, 0.0% heat with a gas boiler and 85.5% are rated D–G; 39 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
677homes with an energy certificate
25.6%solid walls, no insulation
0.0%heated by a gas boiler
39heat pumps
Article 4: An Article 4 direction published by Council of the Isles of Scilly covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), painting the outside, so there these need planning permission too. (Isles of Scilly Article 4 Direction 1975; Isles of Scilly Article 4 Direction 1988; Isles of Scilly Article 4 Direction 1995; Isles of Scilly Article 4 Direction 1998)
What needs planning permission in Isles of Scilly
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
Planning permission needed (an Article 4 direction here removes this right)
Part 1 Class A, A.3(a)
Listed buildings: 100 in the area (grade I: 4, II*: 5). 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: 36% 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 = 677)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
173
25.6%
Cavity wall, unfilled
138
20.4%
Timber frame
96
14.2%
Cavity wall, filled
76
11.2%
Cavity wall, partly insulated
39
5.8%
Modern wall (U-value from the design)
38
5.6%
Cavity wall, insulated (as built or unspecified)
33
4.9%
Solid wall, internal insulation
26
3.8%
Other or not known
21
3.1%
Solid wall, insulated
16
2.4%
Cavity wall, internal or external insulation
14
2.1%
Solid wall, partly insulated
7
1.0%
Heating
Homes
Share
Electric (storage heaters, panels, boiler)
498
73.6%
Oil
56
8.3%
Communal heating
48
7.1%
Heat pump
39
5.8%
Solid fuel (wood, coal)
33
4.9%
LPG
3
0.4%
Loft / roof insulation
Homes
Share
No insulation
79
11.7%
Under 200 mm
147
21.7%
200 mm or more
195
28.8%
Insulated (depth not recorded)
111
16.4%
Flat or other home above
113
16.7%
Other
32
4.7%
Windows
Homes
Share
Double glazed
579
85.5%
Single glazed
78
11.5%
Secondary glazing
19
2.8%
Triple glazed
1
0.1%
CDEFG
Energy rating: A 4 (0.6%) · B 30 (4.4%) · C 64 (9.5%) · D 180 (26.6%) · E 201 (29.7%) · F 123 (18.2%) · G 75 (11.1%). Houses and bungalows: 64% of the homes; solar panels on 0.6% of the certificates. Most common build period on the certificates: before 1900.
Compared with Council of the Isles of Scilly and England
Share of homes
Isles of Scilly
All 2 areas in Council of the Isles of Scilly
England
Solid walls, no insulation
25.6%
27.9%
48.7%
Gas boiler
0.0%
0.0%
66.4%
Rated D–G
85.5%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 43% of these are from 2020 or later (latest 23 September 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 Council of the Isles of Scilly if in doubt.
Boundary: Council of the Isles of Scilly via planning.data.gov.uk (entity 44015932, reference council-of-the-isles-of-scilly-conservation-area-1, 12,005.4 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.