Three metres, or three and a half
Two numbers decide most Ilford kitchen projects. The first is national. On a terraced or semi-detached house you can build 3 metres out from the original back wall without applying, and 4 metres on a detached one, as long as the house still has its permitted development rights and the roof stays under 4 metres high.
The second is Redbridge's own. Its Housing Design guide, adopted in 2019, sets 3.5 metres as the usual maximum depth for a single-storey rear addition to a terrace or a semi, and 4.5 metres for a detached house. That figure only applies once you are making a planning application. It is still the number an officer will hold your drawings against, and the guide is wary of what it calls creep, where each house on a row goes a little further than the one before. Going deeper is possible where the houses either side have already done it.
There is a middle route too. Prior approval lets an attached house go to 6 metres without a full application. The neighbours are notified, and work can't start until the council agrees or 42 days pass without a decision.
Going up a storey at the back
A first floor over the back is a different conversation. Without an application it can project 3 metres and must sit at least 7 metres from the rear boundary, so measure the garden before you get attached to the idea. Through planning, Redbridge wants it no deeper than 3 metres, no wider than half the original back wall, and its eaves no higher than the house's.
Then comes the 45-degree test. Draw a line at 45 degrees from the middle of your neighbour's nearest habitable window, on plan and on the elevation, and the new work has to stay inside it. Where back rooms sit a few feet apart, that line arrives quickly. Ask your designer to draw it before anything else.
At the side, a two-storey addition must step back at least half a metre from the front wall, with its ridge at least half a metre lower than the main roof. That keeps a pair of Gants Hill semis reading as a pair.
Which type suits which Ilford house
Roughly in order of how often each fits the streets here.
Single-storey rear. The first thing most owners in Cranbrook or Goodmayes look at. Keep any flat roof to about 3 metres high, and don't plan to sit on it. Redbridge normally refuses roof terraces on extensions.
Kitchen. On Ilford's narrow-fronted terraces this is usually what the money is really for. Light matters more than depth on a tight plot, so a rooflight over the worktop earns its place.
Side return. Only an option where your terrace has a gap down the side of the back rooms. Nothing, guttering and footings included, may cross onto next door's land unless it becomes a shared party wall.
Open plan. Knocking the old kitchen and dining room through needs a steel beam. Its padstones sit on London Clay, so the engineer should treat them with the same care as the new footings.
Wrap-around. Always an application, because of the side part. Redbridge asks for low 2.4 metre eaves and a shallow pitch, and the 3.5 metre depth still applies.
Two-storey. Most realistic over the side of an interwar semi in Newbury Park or Barkingside. Corner plots get extra scrutiny, and a bulky blank flank wall facing the side road may be refused.
Ground-floor bedroom. Fine for an older relative, provided it opens off the house. Redbridge treats a granny annexe as part of the home, so it needs an internal link and no front door of its own.
Home office. A garden building should stand towards the far end, with eaves no higher than 2.5 metres under a pitched roof. Put a bathroom or bedroom in one and expect a refusal, which is one argument for attaching the office instead.
Planning. In a conservation area there is no permitted development for side extensions or two-storey rear ones, and no new render or cladding either. The Bungalow Estate goes further (see below). Elsewhere, a lawful development certificate is cheap insurance.
Cost. No figures here. Clay footings, a steel and a party wall notice all move the price, and only a builder who has seen your house can price them.
Clay underfoot, water after storms
Most of Redbridge sits on London Clay, which the British Geological Survey calls very susceptible to volume change. It shrinks in dry summers and swells again in winter, usually in the top 1.5 to 2 metres but deeper where tree roots are drawing water. The BGS notes the cracking shows up most in new homes and extensions. So tell your engineer about every large tree near the new wall, yours or the neighbour's.
Water is the other thing to check. More than 100 properties flooded across the borough in July 2021, and Ilford, Seven Kings Water and Goodmayes are among the council's critical drainage areas. If your house is in Flood Zone 2 or 3, an application needs a flood risk assessment. For a minor extension the Environment Agency's standing advice covers it and asks for the new floor 600mm above the estimated flood level, or for flood resistant construction.
The Bungalow Estate
South of Green Lane, between Water Lane and Goodmayes Lane, an Article 4 direction means the bungalows need permission for extensions. The 2018 design guide keeps them single storey. At the back you may go half the depth of the original bungalow, under a flat or monopitch roof, no wider than the house. A side addition must be set back a metre from the front and rear walls and a metre from every boundary, with its ridge at least 3 metres below the main one. Linked side and rear additions are not supported, and new infill porches on unaltered houses are resisted.
Where these facts come from
- Redbridge Housing Design SPD (2019)
- Bungalow Estate design guide (2018)
- GOV.UK: Permitted development rights for householders, technical guidance
- GOV.UK: Flood risk assessment standing advice
- Redbridge Strategic Flood Risk Assessment Level 1 (2015)
- Redbridge Local Flood Risk Management Strategy 2024
- British Geological Survey: clay shrink-swell
- Redbridge Council: protected buildings and conservation areas
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Questions people in Ilford ask
The houses either side have both gone back 4 metres. Can I match them?
Quite possibly. Redbridge's guide allows a deeper single-storey addition where it is consistent with the neighbouring houses. What it resists is going further than they did.
Can my mother have a self-contained annexe in the back garden?
Unlikely. Redbridge expects garden buildings to be used for things incidental to the house, and usually refuses bedrooms, kitchens or bathrooms in them. An attached ground-floor room with an internal door is the route it supports.
How much of the garden can I build over?
Permitted development stops once buildings cover half the garden. Redbridge also encourages keeping 60% of it as soft landscaping, which helps with the surface water that already troubles parts of Ilford.