Solar panels, heat pumps and insulation in St. Clement's And Iffley Road conservation area
In the St. Clement's And Iffley Road conservation area (Oxford), 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 Oxford covers this area but deals with other things (such as changes of use); it does not change the rules below. The area has 35 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. 997 homes inside the boundary have an energy certificate: 46.5% are solid-wall homes with no wall insulation, 66.7% heat with a gas boiler and 42.7% are rated D–G; 14 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
997homes with an energy certificate
46.5%solid walls, no insulation
66.7%heated by a gas boiler
14heat pumps
Article 4: An Article 4 direction published by Oxford covers this area but deals with other things (such as changes of use); it does not change the rules below. (Houses in Multiple Occupation Article 4 Direction)
What needs planning permission in St. Clement's And Iffley Road
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: 35 in the area (grade I: 1, II*: 3). 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: 69% 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 = 997)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
464
46.5%
Cavity wall, insulated (as built or unspecified)
141
14.1%
Modern wall (U-value from the design)
121
12.1%
Cavity wall, partly insulated
107
10.7%
Cavity wall, filled
57
5.7%
Timber frame
35
3.5%
Solid wall, internal insulation
26
2.6%
Cavity wall, unfilled
21
2.1%
Other or not known
11
1.1%
Solid wall, insulated
11
1.1%
Solid wall, partly insulated
2
0.2%
Cavity wall, internal or external insulation
1
0.1%
Heating
Homes
Share
Gas boiler
665
66.7%
Electric (storage heaters, panels, boiler)
226
22.7%
Communal heating
90
9.0%
Heat pump
14
1.4%
LPG
1
0.1%
Other
1
0.1%
Loft / roof insulation
Homes
Share
No insulation
106
10.6%
Under 200 mm
140
14.0%
200 mm or more
141
14.1%
Insulated (depth not recorded)
132
13.2%
Flat or other home above
413
41.4%
Other
65
6.5%
Windows
Homes
Share
Double glazed
864
86.7%
Single glazed
85
8.5%
Secondary glazing
39
3.9%
Other
7
0.7%
Triple glazed
2
0.2%
BCDE
Energy rating: B 107 (10.7%) · C 464 (46.5%) · D 322 (32.3%) · E 95 (9.5%) · F 6 (0.6%) · G 3 (0.3%). Houses and bungalows: 31% of the homes; solar panels on 0.2% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 25 July 1977.
Compared with Oxford and England
Share of homes
St. Clement's And Iffley Road
All 18 areas in Oxford
England
Solid walls, no insulation
46.5%
41.0%
48.7%
Gas boiler
66.7%
69.7%
66.4%
Rated D–G
42.7%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 46% 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 Oxford if in doubt.
Boundary: Oxford City Council via planning.data.gov.uk (entity 44015804, reference SSLZMFZX0009, 37.2 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.