Solar panels, heat pumps and insulation in Darnley Road, Gravesend conservation area
In the Darnley Road, Gravesend conservation area (Gravesham), 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 Gravesham covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), chimneys, flues and soil pipes, painting the outside, so there these need planning permission too. 336 homes inside the boundary have an energy certificate: 75.3% are solid-wall homes with no wall insulation, 92.0% heat with a gas boiler and 62.2% are rated D–G; 2 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
336homes with an energy certificate
75.3%solid walls, no insulation
92.0%heated by a gas boiler
2heat pumps
Article 4: An Article 4 direction published by Gravesham covers this area and removes permitted development rights for replacement windows and doors, and other alterations to the house, alterations to the roof (e.g. rooflights), chimneys, flues and soil pipes, painting the outside, so there these need planning permission too. (Darnley Road - Ar/99/4; Darnley Road CA Extended - Ar/10/6)
What needs planning permission in Darnley Road, Gravesend
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
Planning permission needed (an Article 4 direction here removes this right)
Part 1 Class A, A.3(a)
Listed buildings: none recorded inside the boundary; on a listed building, solar panels and heat pumps are not permitted development and need listed building consent.
Flats: 66% 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 = 336)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
253
75.3%
Modern wall (U-value from the design)
32
9.5%
Solid wall, internal insulation
15
4.5%
Solid wall, insulated
13
3.9%
Cavity wall, insulated (as built or unspecified)
9
2.7%
Cavity wall, unfilled
6
1.8%
Timber frame
3
0.9%
Cavity wall, partly insulated
2
0.6%
Solid wall, external insulation
2
0.6%
Cavity wall, filled
1
0.3%
Heating
Homes
Share
Gas boiler
309
92.0%
Electric (storage heaters, panels, boiler)
22
6.5%
Communal heating
3
0.9%
Heat pump
2
0.6%
Loft / roof insulation
Homes
Share
No insulation
79
23.6%
Under 200 mm
48
14.3%
200 mm or more
35
10.4%
Insulated (depth not recorded)
17
5.1%
Flat or other home above
136
40.6%
Other
20
6.0%
Windows
Homes
Share
Double glazed
292
86.9%
Single glazed
40
11.9%
Secondary glazing
3
0.9%
Triple glazed
1
0.3%
BCDE
Energy rating: B 29 (8.6%) · C 98 (29.2%) · D 133 (39.6%) · E 61 (18.2%) · F 12 (3.6%) · G 3 (0.9%). Houses and bungalows: 34% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 5 May 1990.
Compared with Gravesham and England
Share of homes
Darnley Road, Gravesend
All 23 areas in Gravesham
England
Solid walls, no insulation
75.3%
59.6%
48.7%
Gas boiler
92.0%
68.8%
66.4%
Rated D–G
62.2%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 55% of these are from 2020 or later (latest 23 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 Gravesham if in doubt.
Boundary: Gravesham Borough Council via planning.data.gov.uk (entity 44016185, reference 2008/24/CONARA, 9.3 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.