Solar panels, heat pumps and insulation in St Albans - Midland and GNR Railways conservation area
In the St Albans - Midland and GNR Railways conservation area (St Albans), 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 St Albans covers part of this area (about 16% of it) but deals with other things (such as changes of use); it does not change the rules below. The area has 2 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. 710 homes inside the boundary have an energy certificate: 0.0% are solid-wall homes with no wall insulation, 16.1% heat with a gas boiler and 13.1% are rated D–G; 32 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
710homes with an energy certificate
0.0%solid walls, no insulation
16.1%heated by a gas boiler
32heat pumps
Article 4: An Article 4 direction published by St Albans covers part of this area (about 16% of it) but deals with other things (such as changes of use); it does not change the rules below. (St Albans City Station)
What needs planning permission in St Albans - Midland and GNR Railways
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: 2 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: 92% 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 = 710)
Walls
Homes
Share
Cavity wall, insulated (as built or unspecified)
305
43.0%
Modern wall (U-value from the design)
296
41.7%
Other or not known
85
12.0%
Timber frame
15
2.1%
Cavity wall, filled
4
0.6%
Cavity wall, partly insulated
2
0.3%
Cavity wall, internal or external insulation
1
0.1%
Cavity wall, unfilled
1
0.1%
Solid wall, insulated
1
0.1%
Heating
Homes
Share
Electric (storage heaters, panels, boiler)
518
73.0%
Gas boiler
114
16.1%
Communal heating
46
6.5%
Heat pump
32
4.5%
Loft / roof insulation
Homes
Share
Under 200 mm
19
2.7%
200 mm or more
18
2.5%
Insulated (depth not recorded)
68
9.6%
Flat or other home above
463
65.2%
Other
142
20.0%
Windows
Homes
Share
Double glazed
683
96.2%
Triple glazed
25
3.5%
Single glazed
2
0.3%
BCD
Energy rating: A 2 (0.3%) · B 192 (27.0%) · C 423 (59.6%) · D 86 (12.1%) · E 7 (1.0%). Houses and bungalows: 8% of the homes; solar panels on 0.1% of the certificates. Most common build period on the certificates: 2007-2011. Designated: 24 March 1969.
Compared with St Albans and England
Share of homes
St Albans - Midland and GNR Railways
All 45 areas in St Albans
England
Solid walls, no insulation
0.0%
37.1%
48.7%
Gas boiler
16.1%
76.8%
66.4%
Rated D–G
13.1%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 69% 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 St Albans if in doubt.
Boundary: St Albans City and District Council via planning.data.gov.uk (entity 44010082, reference CA11_6b, 22.4 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.