Ealing's guidance gives dormer margins in metres and says one popular project, hip-to-gable on a semi, will normally be refused if it needs permission. We check that before you spend on design.
Photo: Bill Boaden, BY-SA 2.0
Section 6 of SPD 4 is Ealing's roof extension guidance. Rear dormers are generally more acceptable than side dormers, which can look prominent in the street, and dormers are rarely acceptable on front roof slopes. A roof extension made of dormers should not wrap around two roof slopes or rise above the existing ridge.
The margins are specific. Dormer windows should be located at least 0.5 metres down from the ridge, at least 0.5 metres from the edges or sides of the roof, and at least 0.5 metres above the eaves. The council assesses scale, bulk and visual impact, and in conservation areas it requires traditional designs in size, detailing and materials. The ridge of a house should not be raised for headroom, and mansard extensions that change the roof slope will not usually be acceptable.
The sentence that matters most for Ealing's interwar suburbs is the one on hip-to-gable. If you propose to change a hipped roof into a gable end and the house is semi-detached or terraced, SPD 4 says planning permission, if required, will normally be refused, because it is likely to unbalance the symmetry of the pair or terrace. Class B permitted development can still cover the conversion where it applies, which is why the permission question comes first.
Five rules in section 6 shape an Ealing loft drawing.
| Feature | What Ealing says |
|---|---|
| Dormer position | At least 0.5 m down from ridge, 0.5 m in from edges, 0.5 m above eaves |
| Front slope | Dormers rarely acceptable |
| Raised ridge | Not to be raised for headroom |
| Mansard | Changing the slope will not usually be acceptable |
| Hip-to-gable on semi or terrace | Planning permission, if required, will normally be refused |
Ealing Council, SPD 4 Residential Extensions, section 6.
The fee includes our measured visit. The bracketed figure applies if you already have measured drawings.
Ealing's Article 4 page lists the directions by conservation area. Bedford Park's covers the enlargement of a dwelling by an addition or alteration to its roof, and any other alteration to the roof. Churchfields (Half Acre Road) covers roof enlargement. The Grove in Ealing Town Centre covers both. Hanger Hill (Haymills) Estate covers rooflights and replacing roofing materials, and Brentham Garden Estate and Hanger Hill Garden Estate cover replacing roof materials and chimneys.
For example, a house in Bedford Park cannot use Class B at all: even a rooflight on the rear slope needs a planning application there. A semi in Greenford or Perivale outside those areas may be able to use Class B and prove it with a lawful development certificate, so long as the hip-to-gable and dormer fit the statutory limits.
On timing, Ealing decided 424 householder applications in the year to June 2026 with prior approvals set aside, and 407 inside 8 weeks. The council aims to validate within 5 to 10 working days and returns an invalid application if nothing is heard within 28 days.
Every figure is linked to the page or document we read.
Ealing's SPD 4 says dormer windows should be located at least 0.5 metres down from the ridge, 0.5 metres from the edges of the roof and 0.5 metres above the eaves.
Source: Ealing Council, SPD 4 Residential Extensions, section 6SPD 4 says that where a hipped roof on a semi-detached or terraced house is changed to a gable and permission is needed, it will normally be refused.
Source: Ealing Council, SPD 4 Residential Extensions, section 6Ealing has Article 4 directions in 6 conservation areas, with roof controls in Bedford Park, Churchfields (Half Acre Road), the Grove and Hanger Hill (Haymills) Estate.
Source: Ealing Council, Article 4 DirectionsEaling aims to validate applications within 5 to 10 working days and returns an invalid one if nothing is heard within 28 days.
Source: Ealing Council, ValidationEaling decided 424 householder applications between July 2025 and June 2026, prior approvals excluded, and 407 of them were decided within 8 weeks.
Source: MHCLG, Planning application statistics PS2, July 2025 to June 2026Class B permits a roof extension of up to 40 cubic metres on a terraced house and 50 cubic metres in any other case.
Source: legislation.gov.uk, GPDO 2015, Schedule 2, Part 1, Class BTell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
If the house is semi-detached or terraced and planning permission is required, SPD 4 says it will normally be refused because it unbalances the symmetry of the pair or terrace. Where Class B permitted development applies, no application is needed, but a certificate proves it.
SPD 4 says dormer windows should sit at least 0.5 metres down from the ridge, at least 0.5 metres from the edges of the roof and at least 0.5 metres above the eaves. They should not wrap around two slopes or exceed the ridge height.
Rarely. SPD 4 says dormers are rarely acceptable on front roof slopes because they are likely to interfere with the original design of the house and be visually intrusive in the street scene.
Yes in both. Bedford Park's direction covers any alteration to the roof, and the Hanger Hill (Haymills) direction covers alteration to roof slopes, including rooflights. Check the direction for your street before ordering anything.
£765 inc survey (£565 if you supply measured drawings) for a rear dormer. That covers the measured survey, the drawings and the submission, with free revisions until the council decides. Ealing's own application fee is separate.
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