Solar panels, heat pumps and insulation in Hartley Wintney conservation area
In the Hartley Wintney conservation area (Hart), 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 Hart covers this area, but the published data does not say which rights it removes — check the direction before any work. The area has 47 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. 435 homes inside the boundary have an energy certificate: 40.9% are solid-wall homes with no wall insulation, 85.7% heat with a gas boiler and 61.1% are rated D–G; 20 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
435homes with an energy certificate
40.9%solid walls, no insulation
85.7%heated by a gas boiler
20heat pumps
Article 4: An Article 4 direction published by Hart covers this area, but the published data does not say which rights it removes — check the direction before any work. (Hartley Wintney; Land North Of Springfield Avenue Hartley Wintney)
What needs planning permission in Hartley Wintney
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: 47 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: 24% 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 = 435)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
178
40.9%
Modern wall (U-value from the design)
76
17.5%
Cavity wall, insulated (as built or unspecified)
56
12.9%
Cavity wall, filled
50
11.5%
Cavity wall, unfilled
44
10.1%
Cavity wall, partly insulated
12
2.8%
Timber frame
8
1.8%
Solid wall, insulated
6
1.4%
Solid wall, internal insulation
5
1.1%
Heating
Homes
Share
Gas boiler
373
85.7%
Communal heating
26
6.0%
Heat pump
20
4.6%
Electric (storage heaters, panels, boiler)
15
3.4%
Oil
1
0.2%
Loft / roof insulation
Homes
Share
No insulation
56
12.9%
Under 200 mm
133
30.6%
200 mm or more
92
21.1%
Insulated (depth not recorded)
50
11.5%
Flat or other home above
45
10.3%
Other
59
13.6%
Windows
Homes
Share
Double glazed
348
80.0%
Single glazed
64
14.7%
Secondary glazing
23
5.3%
BCDE
Energy rating: A 4 (0.9%) · B 59 (13.6%) · C 106 (24.4%) · D 191 (43.9%) · E 66 (15.2%) · F 7 (1.6%) · G 2 (0.5%). Houses and bungalows: 76% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 November 2008.
Compared with Hart and England
Share of homes
Hartley Wintney
All 39 areas in Hart
England
Solid walls, no insulation
40.9%
25.9%
48.7%
Gas boiler
85.7%
80.4%
66.4%
Rated D–G
61.1%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 46% of these are from 2020 or later (latest 6 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 Hart if in doubt.
Boundary: Hart District Council via planning.data.gov.uk (entity 44016488, reference 17-1, 169.2 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.