Solar panels, heat pumps and insulation in Bishops Waltham conservation area
In the Bishops Waltham conservation area (Winchester), 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 98 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. 314 homes inside the boundary have an energy certificate: 27.7% are solid-wall homes with no wall insulation, 75.2% heat with a gas boiler and 48.7% are rated D–G; 8 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
314homes with an energy certificate
27.7%solid walls, no insulation
75.2%heated by a gas boiler
8heat pumps
Article 4: Winchester does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Bishops Waltham
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: 98 in the area (grade I: 0, II*: 3). 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: 48% 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 = 314)
Walls
Homes
Share
Cavity wall, insulated (as built or unspecified)
131
41.7%
Solid wall (brick or stone), no insulation
87
27.7%
Cavity wall, filled
36
11.5%
Modern wall (U-value from the design)
15
4.8%
Cavity wall, unfilled
14
4.5%
Solid wall, insulated
10
3.2%
Timber frame
8
2.5%
Cavity wall, partly insulated
7
2.2%
Solid wall, internal insulation
3
1.0%
Other or not known
2
0.6%
Cavity wall, internal or external insulation
1
0.3%
Heating
Homes
Share
Gas boiler
236
75.2%
Electric (storage heaters, panels, boiler)
69
22.0%
Heat pump
8
2.5%
Communal heating
1
0.3%
Loft / roof insulation
Homes
Share
No insulation
29
9.2%
Under 200 mm
75
23.9%
200 mm or more
93
29.6%
Insulated (depth not recorded)
30
9.6%
Flat or other home above
73
23.2%
Other
14
4.5%
Windows
Homes
Share
Double glazed
257
81.8%
Single glazed
42
13.4%
Secondary glazing
14
4.5%
Other
1
0.3%
CDE
Energy rating: A 1 (0.3%) · B 19 (6.1%) · C 141 (44.9%) · D 107 (34.1%) · E 39 (12.4%) · F 6 (1.9%) · G 1 (0.3%). Houses and bungalows: 52% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 September 1973.
Compared with Winchester and England
Share of homes
Bishops Waltham
All 34 areas in Winchester
England
Solid walls, no insulation
27.7%
27.2%
48.7%
Gas boiler
75.2%
70.2%
66.4%
Rated D–G
48.7%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 48% of these are from 2020 or later (latest 12 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 Winchester if in doubt.
Boundary: Winchester City Council via planning.data.gov.uk (entity 44006840, reference 4971, 37.1 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.