Solar panels, heat pumps and insulation in Totteridge conservation area
In the Totteridge 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), chimneys, flues and soil pipes, painting the outside, so there these need planning permission too. The area has 36 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. 331 homes inside the boundary have an energy certificate: 30.2% are solid-wall homes with no wall insulation, 93.4% heat with a gas boiler and 62.2% are rated D–G; 16 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
331homes with an energy certificate
30.2%solid walls, no insulation
93.4%heated by a gas boiler
16heat 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), chimneys, flues and soil pipes, painting the outside, so there these need planning permission too. (Article 4 Agricultural Land Restriction Area 1; Article 4 Agricultural Land Restriction Area 2; Article 4 Small Houses in Multiple Occupation (HMO) Area 1; Article 4 for Totteridge CA Area 1; Article 4 for Totteridge CA Area 2; Article 4 for Totteridge CA Area 3)
What needs planning permission in Totteridge
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: 36 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: 7% 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 = 331)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
100
30.2%
Cavity wall, unfilled
81
24.5%
Cavity wall, insulated (as built or unspecified)
52
15.7%
Modern wall (U-value from the design)
45
13.6%
Cavity wall, filled
19
5.7%
Cavity wall, partly insulated
14
4.2%
Cavity wall, internal or external insulation
5
1.5%
Solid wall, internal insulation
5
1.5%
Other or not known
3
0.9%
Solid wall, insulated
3
0.9%
Timber frame
3
0.9%
Solid wall, partly insulated
1
0.3%
Heating
Homes
Share
Gas boiler
309
93.4%
Heat pump
16
4.8%
Electric (storage heaters, panels, boiler)
3
0.9%
Communal heating
1
0.3%
LPG
1
0.3%
Oil
1
0.3%
Loft / roof insulation
Homes
Share
No insulation
51
15.4%
Under 200 mm
80
24.2%
200 mm or more
54
16.3%
Insulated (depth not recorded)
97
29.3%
Flat or other home above
7
2.1%
Other
42
12.7%
Windows
Homes
Share
Double glazed
276
83.4%
Single glazed
40
12.1%
Secondary glazing
14
4.2%
Triple glazed
1
0.3%
BCDE
Energy rating: A 7 (2.1%) · B 33 (10.0%) · C 85 (25.7%) · D 117 (35.3%) · E 62 (18.7%) · F 24 (7.3%) · G 3 (0.9%). Houses and bungalows: 93% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: 1930-1949. Designated: 20 December 1968.
Compared with Barnet and England
Share of homes
Totteridge
All 16 areas in Barnet
England
Solid walls, no insulation
30.2%
48.2%
48.7%
Gas boiler
93.4%
84.8%
66.4%
Rated D–G
62.2%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 50% of these are from 2020 or later (latest 19 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 44002422, reference CA12, 175.5 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.