Solar panels, heat pumps and insulation in Longhirst conservation area
In the Longhirst 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 19% 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), painting the outside, so there these need planning permission too. The area has 28 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. 97 homes inside the boundary have an energy certificate: 26% are solid-wall homes with no wall insulation, 91% heat with a gas boiler and 42% are rated D–G; 2 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
97homes with an energy certificate
26%solid walls, no insulation
91%heated by a gas boiler
2heat pumps
Article 4: An Article 4 direction published by Northumberland covers part of this area (about 19% 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), painting the outside, so there these need planning permission too. (Longhirst)
What needs planning permission in Longhirst
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: 28 in the area (grade I: 0, 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: 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 = 97)
Walls
Homes
Share
Modern wall (U-value from the design)
52
54%
Solid wall (brick or stone), no insulation
25
26%
Cavity wall, insulated (as built or unspecified)
15
15%
Solid wall, insulated
2
2%
Cavity wall, filled
1
1%
Cavity wall, partly insulated
1
1%
Cavity wall, unfilled
1
1%
Heating
Homes
Share
Gas boiler
88
91%
Electric (storage heaters, panels, boiler)
5
5%
Heat pump
2
2%
Communal heating
1
1%
Oil
1
1%
Loft / roof insulation
Homes
Share
No insulation
7
7%
Under 200 mm
3
3%
200 mm or more
29
30%
Insulated (depth not recorded)
5
5%
Flat or other home above
17
18%
Other
36
37%
Windows
Homes
Share
Double glazed
83
86%
Single glazed
12
12%
Secondary glazing
2
2%
BCDE
Energy rating: B 11 (11%) · C 45 (46%) · D 28 (29%) · E 11 (11%) · F 1 (1%) · G 1 (1%). Houses and bungalows: 75% of the homes; solar panels on 0% of the certificates. Most common build period on the certificates: 2019. Designated: 5 January 1981.
Compared with Northumberland and England
Share of homes
Longhirst
All 70 areas in Northumberland
England
Solid walls, no insulation
26%
49.9%
48.7%
Gas boiler
91%
64.7%
66.4%
Rated D–G
42%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 32% of these are from 2020 or later (latest 31 July 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 44013585, reference CA41, 30.4 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.