Solar panels, heat pumps and insulation in Bishop's Stortford conservation area
In the Bishop's Stortford conservation area (East Hertfordshire), 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 78 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. 2,269 homes inside the boundary have an energy certificate: 36.7% are solid-wall homes with no wall insulation, 64.7% heat with a gas boiler and 50.8% 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
2,269homes with an energy certificate
36.7%solid walls, no insulation
64.7%heated by a gas boiler
20heat pumps
Article 4: East Hertfordshire does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Bishop's Stortford
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: 78 in the area (grade I: 2, II*: 4). 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: 52% 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 = 2,269)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
832
36.7%
Cavity wall, insulated (as built or unspecified)
654
28.8%
Modern wall (U-value from the design)
195
8.6%
Cavity wall, filled
125
5.5%
Cavity wall, unfilled
115
5.1%
Timber frame
112
4.9%
Other or not known
88
3.9%
Cavity wall, partly insulated
74
3.3%
Solid wall, insulated
33
1.5%
Solid wall, internal insulation
29
1.3%
Cavity wall, internal or external insulation
4
0.2%
Solid wall, external insulation
4
0.2%
Solid wall, partly insulated
4
0.2%
Heating
Homes
Share
Gas boiler
1,469
64.7%
Electric (storage heaters, panels, boiler)
662
29.2%
Communal heating
112
4.9%
Heat pump
20
0.9%
LPG
2
0.1%
Oil
2
0.1%
Solid fuel (wood, coal)
2
0.1%
Loft / roof insulation
Homes
Share
No insulation
214
9.4%
Under 200 mm
524
23.1%
200 mm or more
400
17.6%
Insulated (depth not recorded)
324
14.3%
Flat or other home above
673
29.7%
Other
134
5.9%
Windows
Homes
Share
Double glazed
2,033
89.6%
Single glazed
175
7.7%
Secondary glazing
57
2.5%
Triple glazed
4
0.2%
BCDE
Energy rating: A 1 (0.0%) · B 312 (13.8%) · C 804 (35.4%) · D 751 (33.1%) · E 352 (15.5%) · F 41 (1.8%) · G 8 (0.4%). Houses and bungalows: 48% of the homes; solar panels on 0.4% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 7 October 1968.
Compared with East Hertfordshire and England
Share of homes
Bishop's Stortford
All 42 areas in East Hertfordshire
England
Solid walls, no insulation
36.7%
32.5%
48.7%
Gas boiler
64.7%
66.6%
66.4%
Rated D–G
50.8%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 53% of these are from 2020 or later (latest 28 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 East Hertfordshire if in doubt.
Boundary: East Hertfordshire District Council via planning.data.gov.uk (entity 44014201, reference CA06, 130.7 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.