Solar panels, heat pumps and insulation in Aston conservation area
In the Aston conservation area (West Oxfordshire), 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 West Oxfordshire covers part of this area (about 1% of it) but deals with other things (such as changes of use); it does not change the rules below. The area has 11 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. 345 homes inside the boundary have an energy certificate: 14.5% are solid-wall homes with no wall insulation, 87.5% heat with a gas boiler and 53.6% 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
345homes with an energy certificate
14.5%solid walls, no insulation
87.5%heated by a gas boiler
1heat pumps
Article 4: An Article 4 direction published by West Oxfordshire covers part of this area (about 1% of it) but deals with other things (such as changes of use); it does not change the rules below. (Aston Works)
What needs planning permission in Aston
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: 11 in the area. 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: 6% 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 = 345)
Walls
Homes
Share
Cavity wall, filled
105
30.4%
Modern wall (U-value from the design)
67
19.4%
Cavity wall, insulated (as built or unspecified)
66
19.1%
Solid wall (brick or stone), no insulation
50
14.5%
Cavity wall, unfilled
32
9.3%
Cavity wall, partly insulated
8
2.3%
Solid wall, external insulation
7
2.0%
Solid wall, insulated
7
2.0%
Timber frame
2
0.6%
Other or not known
1
0.3%
Heating
Homes
Share
Gas boiler
302
87.5%
Electric (storage heaters, panels, boiler)
26
7.5%
LPG
7
2.0%
Oil
6
1.7%
Solid fuel (wood, coal)
3
0.9%
Heat pump
1
0.3%
Loft / roof insulation
Homes
Share
No insulation
14
4.1%
Under 200 mm
98
28.5%
200 mm or more
106
30.8%
Insulated (depth not recorded)
50
14.5%
Flat or other home above
8
2.3%
Other
68
19.8%
Windows
Homes
Share
Double glazed
337
97.7%
Single glazed
5
1.4%
Secondary glazing
2
0.6%
Other
1
0.3%
BCDE
Energy rating: B 67 (19.4%) · C 93 (27.0%) · D 146 (42.3%) · E 29 (8.4%) · F 8 (2.3%) · G 2 (0.6%). Houses and bungalows: 94% of the homes; solar panels on 2.9% of the certificates. Most common build period on the certificates: 1950-1966. Designated: 7 January 1998.
Compared with West Oxfordshire and England
Share of homes
Aston
All 50 areas in West Oxfordshire
England
Solid walls, no insulation
14.5%
39.3%
48.7%
Gas boiler
87.5%
61.6%
66.4%
Rated D–G
53.6%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 49% of these are from 2020 or later (latest 26 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 West Oxfordshire if in doubt.
Boundary: West Oxfordshire District Council via planning.data.gov.uk (entity 44014522, reference CONARA/047, 57.0 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.