Solar panels, heat pumps and insulation in Derby Park conservation area
In the Derby Park conservation area (Sefton), 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 Sefton covers this area but deals with other things (such as changes of use); it does not change the rules below. The area has 4 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. 871 homes inside the boundary have an energy certificate: 43.9% are solid-wall homes with no wall insulation, 68.4% heat with a gas boiler and 47.1% are rated D–G; 1 has 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
871homes with an energy certificate
43.9%solid walls, no insulation
68.4%heated by a gas boiler
1heat pumps
Article 4: An Article 4 direction published by Sefton covers this area but deals with other things (such as changes of use); it does not change the rules below. (Bootle and Waterloo HMO)
What needs planning permission in Derby Park
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: 4 in the area (grade I: 1, II*: 0). 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: 65% 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 = 871)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
382
43.9%
Cavity wall, filled
174
20.0%
Modern wall (U-value from the design)
97
11.1%
Cavity wall, insulated (as built or unspecified)
95
10.9%
Solid wall, internal insulation
42
4.8%
Cavity wall, unfilled
39
4.5%
Timber frame
13
1.5%
Cavity wall, partly insulated
11
1.3%
Solid wall, insulated
11
1.3%
Other or not known
7
0.8%
Heating
Homes
Share
Gas boiler
596
68.4%
Communal heating
164
18.8%
Electric (storage heaters, panels, boiler)
107
12.3%
LPG
2
0.2%
Heat pump
1
0.1%
Solid fuel (wood, coal)
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
110
12.6%
Under 200 mm
119
13.7%
200 mm or more
173
19.9%
Insulated (depth not recorded)
75
8.6%
Flat or other home above
351
40.3%
Other
43
4.9%
Windows
Homes
Share
Double glazed
831
95.4%
Single glazed
34
3.9%
Triple glazed
5
0.6%
Secondary glazing
1
0.1%
BCDE
Energy rating: A 16 (1.8%) · B 87 (10.0%) · C 358 (41.1%) · D 270 (31.0%) · E 111 (12.7%) · F 23 (2.6%) · G 6 (0.7%). Houses and bungalows: 35% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 1 July 1990.
Compared with Sefton and England
Share of homes
Derby Park
All 25 areas in Sefton
England
Solid walls, no insulation
43.9%
32.5%
48.7%
Gas boiler
68.4%
70.7%
66.4%
Rated D–G
47.1%
—
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 Sefton if in doubt.
Boundary: Sefton Metropolitan Borough Council via planning.data.gov.uk (entity 44014044, reference CA9, 37.4 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.