Solar panels, heat pumps and insulation in Wood Street conservation area
In the Wood Street conservation area (Barnet), 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 Barnet 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), painting the outside, so there these need planning permission too. The area has 31 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. 575 homes inside the boundary have an energy certificate: 43.5% are solid-wall homes with no wall insulation, 69.9% heat with a gas boiler and 44.9% 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
575homes with an energy certificate
43.5%solid walls, no insulation
69.9%heated by a gas boiler
1heat pumps
Article 4: An Article 4 direction published by Barnet 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), painting the outside, so there these need planning permission too. (Article 4 Small Houses in Multiple Occupation (HMO) Area 1; Article 4 for Wood Street CA Area 1; Article 4 for Wood Street CA Area 2)
What needs planning permission in Wood Street
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: 31 in the area (grade I: 0, II*: 1). 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: 78% 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 = 575)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
250
43.5%
Cavity wall, insulated (as built or unspecified)
131
22.8%
Modern wall (U-value from the design)
96
16.7%
Solid wall, insulated
27
4.7%
Timber frame
18
3.1%
Cavity wall, unfilled
16
2.8%
Solid wall, internal insulation
15
2.6%
Cavity wall, filled
9
1.6%
Cavity wall, partly insulated
5
0.9%
Other or not known
5
0.9%
Solid wall, partly insulated
2
0.3%
Cavity wall, internal or external insulation
1
0.2%
Heating
Homes
Share
Gas boiler
402
69.9%
Electric (storage heaters, panels, boiler)
130
22.6%
Communal heating
41
7.1%
Heat pump
1
0.2%
Solid fuel (wood, coal)
1
0.2%
Loft / roof insulation
Homes
Share
No insulation
56
9.8%
Under 200 mm
93
16.2%
200 mm or more
65
11.3%
Insulated (depth not recorded)
77
13.4%
Flat or other home above
217
37.8%
Other
66
11.5%
Windows
Homes
Share
Double glazed
486
84.5%
Single glazed
72
12.5%
Secondary glazing
15
2.6%
Triple glazed
2
0.3%
BCDE
Energy rating: B 102 (17.7%) · C 215 (37.4%) · D 185 (32.2%) · E 65 (11.3%) · F 7 (1.2%) · G 1 (0.2%). Houses and bungalows: 22% of the homes; solar panels on 0.0% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 25 April 1969.
Compared with Barnet and England
Share of homes
Wood Street
All 16 areas in Barnet
England
Solid walls, no insulation
43.5%
48.2%
48.7%
Gas boiler
69.9%
84.8%
66.4%
Rated D–G
44.9%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 57% of these are from 2020 or later (latest 30 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 Barnet if in doubt.
Boundary: London Borough of Barnet via planning.data.gov.uk (entity 44002423, reference CA03, 27.4 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.