Solar panels, heat pumps and insulation in Holy Island conservation area
In the Holy Island conservation area (Northumberland), 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 Northumberland covers part of this area (about 18% of it) and removes permitted development rights for replacement windows and doors, and other alterations to the house, so there these need planning permission too. The area has 24 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. 76 homes inside the boundary have an energy certificate: 59% are solid-wall homes with no wall insulation, 0% heat with a gas boiler and 83% are rated D–G; 4 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
76homes with an energy certificate
59%solid walls, no insulation
0%heated by a gas boiler
4heat pumps
Article 4: An Article 4 direction published by Northumberland covers part of this area (about 18% of it) and removes permitted development rights for replacement windows and doors, and other alterations to the house, so there these need planning permission too. (Holy Island)
What needs planning permission in Holy Island
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: 24 in the area (grade I: 3, II*: 1). 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: 4% 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 = 76)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
45
59%
Cavity wall, filled
8
11%
Solid wall, internal insulation
7
9%
Timber frame
6
8%
Cavity wall, insulated (as built or unspecified)
4
5%
Cavity wall, unfilled
3
4%
Solid wall, partly insulated
2
3%
Modern wall (U-value from the design)
1
1%
Heating
Homes
Share
Oil
44
58%
Electric (storage heaters, panels, boiler)
20
26%
LPG
6
8%
Heat pump
4
5%
Solid fuel (wood, coal)
2
3%
Loft / roof insulation
Homes
Share
No insulation
13
17%
Under 200 mm
16
21%
200 mm or more
32
42%
Insulated (depth not recorded)
14
18%
Other
1
1%
Windows
Homes
Share
Double glazed
72
95%
Single glazed
2
3%
Secondary glazing
1
1%
Triple glazed
1
1%
CDEF
Energy rating: C 13 (17%) · D 23 (30%) · E 20 (26%) · F 15 (20%) · G 5 (7%). Houses and bungalows: 96% of the homes; solar panels on 12% of the certificates. Most common build period on the certificates: before 1900. Designated: 23 November 1972.
Compared with Northumberland and England
Share of homes
Holy Island
All 70 areas in Northumberland
England
Solid walls, no insulation
59%
49.9%
48.7%
Gas boiler
0%
64.7%
66.4%
Rated D–G
83%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 54% of these are from 2020 or later (latest 30 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 Northumberland if in doubt.
Boundary: Northumberland County Council via planning.data.gov.uk (entity 44013569, reference CA34, 480.9 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.