Solar panels, heat pumps and insulation in Boston conservation area
In the Boston conservation area (Boston), 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 225 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. 1,403 homes inside the boundary have an energy certificate: 54.4% are solid-wall homes with no wall insulation, 67.6% heat with a gas boiler and 63.7% are rated D–G; 9 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
1,403homes with an energy certificate
54.4%solid walls, no insulation
67.6%heated by a gas boiler
9heat pumps
Article 4: Boston does not publish Article 4 areas on planning.data.gov.uk — check with the council.
What needs planning permission in Boston
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: 225 in the area (grade I: 4, II*: 13). 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 = 1,403)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
763
54.4%
Cavity wall, insulated (as built or unspecified)
276
19.7%
Solid wall, internal insulation
118
8.4%
Modern wall (U-value from the design)
94
6.7%
Cavity wall, filled
35
2.5%
Cavity wall, unfilled
30
2.1%
Timber frame
23
1.6%
Cavity wall, partly insulated
17
1.2%
Solid wall, insulated
15
1.1%
Cavity wall, internal or external insulation
12
0.9%
Other or not known
10
0.7%
Solid wall, partly insulated
6
0.4%
Solid wall, external insulation
4
0.3%
Heating
Homes
Share
Gas boiler
949
67.6%
Electric (storage heaters, panels, boiler)
424
30.2%
Communal heating
17
1.2%
Heat pump
9
0.6%
Other
3
0.2%
LPG
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
223
15.9%
Under 200 mm
240
17.1%
200 mm or more
374
26.7%
Insulated (depth not recorded)
134
9.6%
Flat or other home above
365
26.0%
Other
66
4.7%
Windows
Homes
Share
Double glazed
1,110
79.1%
Single glazed
232
16.5%
Secondary glazing
59
4.2%
Triple glazed
2
0.1%
CDE
Energy rating: A 2 (0.1%) · B 43 (3.1%) · C 464 (33.1%) · D 577 (41.1%) · E 264 (18.8%) · F 39 (2.8%) · G 14 (1.0%). Houses and bungalows: 48% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: before 1900. Designated: 1 January 1969.
Compared with Boston and England
Share of homes
Boston
All 11 areas in Boston
England
Solid walls, no insulation
54.4%
53.9%
48.7%
Gas boiler
67.6%
67.4%
66.4%
Rated D–G
63.7%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 63% of these are from 2020 or later (latest 24 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 Boston if in doubt.
Boundary: Boston Borough Council via planning.data.gov.uk (entity 44001565, reference 7601, 68.7 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.