Solar panels, heat pumps and insulation in Thirsk and Sowerby conservation area
In the Thirsk and Sowerby conservation area (North Yorkshire), 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. The area has 80 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. 1,092 homes inside the boundary have an energy certificate: 49.5% are solid-wall homes with no wall insulation, 78.5% heat with a gas boiler and 54.6% are rated D–G; 3 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
1,092homes with an energy certificate
49.5%solid walls, no insulation
78.5%heated by a gas boiler
3heat pumps
Article 4: North Yorkshire does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Thirsk and Sowerby
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), unless an Article 4 direction removes it — check with the council
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), unless an Article 4 direction removes it — check with the council
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)
Prior approval of appearance from the council, unless an Article 4 direction removes it — check with the council
Replacement windows and doors of similar appearance
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 1 Class A, A.3(a)
Listed buildings: 80 in the area (grade I: 1, 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: 34% 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 = 1,092)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
540
49.5%
Cavity wall, insulated (as built or unspecified)
241
22.1%
Modern wall (U-value from the design)
105
9.6%
Cavity wall, filled
81
7.4%
Cavity wall, unfilled
32
2.9%
Solid wall, internal insulation
29
2.7%
Timber frame
26
2.4%
Solid wall, insulated
19
1.7%
Cavity wall, partly insulated
14
1.3%
Cavity wall, internal or external insulation
4
0.4%
Solid wall, partly insulated
1
0.1%
Heating
Homes
Share
Gas boiler
857
78.5%
Electric (storage heaters, panels, boiler)
144
13.2%
Communal heating
79
7.2%
Solid fuel (wood, coal)
5
0.5%
Oil
4
0.4%
Heat pump
3
0.3%
Loft / roof insulation
Homes
Share
No insulation
161
14.7%
Under 200 mm
192
17.6%
200 mm or more
358
32.8%
Insulated (depth not recorded)
138
12.6%
Flat or other home above
182
16.7%
Other
61
5.6%
Windows
Homes
Share
Double glazed
968
88.6%
Single glazed
99
9.1%
Secondary glazing
25
2.3%
BCDE
Energy rating: B 118 (10.8%) · C 378 (34.6%) · D 405 (37.1%) · E 155 (14.2%) · F 23 (2.1%) · G 13 (1.2%). Houses and bungalows: 66% of the homes; solar panels on 0.4% of the certificates. Most common build period on the certificates: before 1900. Designated: 27 February 1990.
Compared with North Yorkshire and England
Share of homes
Thirsk and Sowerby
All 248 areas in North Yorkshire
England
Solid walls, no insulation
49.5%
54.2%
48.7%
Gas boiler
78.5%
64.9%
66.4%
Rated D–G
54.6%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 49% of these are from 2020 or later (latest 27 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 North Yorkshire if in doubt.
Boundary: North Yorkshire Council via planning.data.gov.uk (entity 44004776, reference 3791, 114.3 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.