House Extensions Ilford
Single storey rear and double storey extensions in Ilford, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
Ilford's bay-fronted Victorian and Edwardian terraces, with their rear closet wings and side returns, extend beautifully. GS Renovation draws on our founder's 30+ years on the tools to add space to IG1 homes, from a modest kitchen extension to a full wrap-around. We handle the foundations, the steel, the roof and the fit-out, and we guide you through Redbridge Council's planning rules.
In Ilford, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Ilford: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Ilford
Ilford range: choose above
Side-return and rear extensions in Ilford
The side return on an Ilford terrace, that narrow strip beside the closet wing, is often dead space. Filling it in and extending to the rear turns a cramped galley kitchen into an open-plan kitchen-diner that runs the full width of the house. We dig and pour the foundations to the required depth, allowing for the mature trees around Valentines Park and Wanstead Park that can affect ground conditions on clay soils.
Steel beams tie the new opening back into the original structure, sized by an engineer and inspected by building control. We build up the walls, form the roof, whether a flat roof with rooflights or a pitched addition, and weather it in before moving inside. Where the extension sits against a neighbour's boundary, which is common on these tightly packed IG1 plots, the Party Wall Act applies and you serve the notices.
Housing in Ilford
Around 14,670 homes make up Ilford on the valuation list; 53% are flats and 47% houses, and 66% date from before 1919, 5% from between the wars and 29% from after 1945. Where most homes are flats, a flat in Ilford has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.
Extending an Ilford ground floor flat without permitted development
53% of homes in Ilford are flats, and a flat has no householder permitted development rights to extend, so a rear extension to a ground floor flat always needs a planning application. Nor can a flat use Redbridge's planning fast track, which is limited to a single dwellinghouse and is closed to any site in a conservation area. An Ilford flat owner should therefore allow for the standard application period before any build date. The lease adds a second consent, because the freeholder normally owns the outside walls, and the owner upstairs is affected by a new roof under their windows. We bring those three conversations together before drawings are finalised.
For houses, the test is proportion. The Redbridge Local Plan backs a household extension when it stays subordinate to the house it is added to, whether measured by size, scale or height. 44% of homes in Ilford are terraced houses, and on a terrace an extension is read against the house and the neighbour's rear addition beside it. A side infill that stays below the first floor windows and keeps the line of the old addition is easier to show as subordinate. One that rises past the neighbour's sills is harder. We ask for the elevation drawings to show both houses, so the design is judged the way a planning officer will look at it.
Planning permission for Ilford extensions
Many single-storey rear extensions in Ilford fall under permitted development, meaning no full planning application is needed provided you stay within the size, height and materials limits. A double-storey extension, a build close to the front, or work on a property in one of Redbridge's conservation areas usually needs planning permission from Redbridge Council. We assess your specific house first and tell you honestly which route applies before any drawings are commissioned.
Whichever route your extension takes, the building work itself must meet building regulations, covering foundations, structure, insulation, drainage and fire safety, all inspected as we go. We can recommend architects and structural engineers, or work to plans you already hold. From the first trench to the final coat of paint, one GS Renovation team runs the site, so you are not left chasing separate trades across a half-finished IG1 extension.
Kitchen extensions in Ilford
53% of homes in Ilford are flats, and a flat has no householder permitted development, so a ground-floor flat's kitchen extension needs planning permission from Redbridge Council and the freeholder's consent. Most kitchen extensions here are on the 47% of homes that are houses. The fit-out is priced on its own page, kitchen renovation in Ilford; the build figures are in the table above.
Double storey extensions in Ilford
Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Ilford often needs planning permission from Redbridge Council. On the 44% of homes that are terraced, the neighbours' windows usually decide the depth. Redbridge Council says the borough has 16 conservation areas (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- Party wall process explained, and the extension built to the award
- Scaffolding, site set-up and safe access on tight terraced plots
- Flat and pitched roofs with rooflights or lanterns
VOA Council Tax stock of properties, March 2025, for all 5 statistical areas in Ilford. Counts rounded by the VOA.
The GS Renovation Difference in Ilford
Homeowners across Ilford and neighbouring Woodford and Wanstead trust GS Renovation because we deliver the whole extension, structure, roof, services and finish, as one accountable job. We know how these IG1 terraces are built, where the load paths run and how Redbridge Council handles planning. Our founder's 30+ years of work means fewer surprises and a build that adds real, lasting value.
- Insulation and thermal detailing to current regulations
- Fully insured, with cover in place on every site
- Building control inspected at foundation, damp course and steel stages
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George was very friendly and helpful from start to finish. He worked really hard to ensure our kitchen was installed to a high standard and was…
My husband and I are extremely pleased with the work. The standard of the work is outstanding and Saiid has a great eye for detail and will not leave…
FAQ
Frequently Asked Questions about House Extensions Ilford
Does the cost of house extensions rise in a late Victorian or Edwardian Ilford property?
In a late Victorian or Edwardian Ilford home the unknowns behind plaster are what move a house extensions figure within £2,000 to £2,800 per m² for a rear extension (indicative), which is why the IG1 survey matters more there. GS Renovation prices the visible work, names the risks, and agrees anything additional in writing. The approvals do not change with age: building regulations approval from foundations to completion applies either way.
Will my Ilford rear extension need planning permission or is it permitted development?
Many single-storey rear extensions on Ilford terraces are permitted development if they stay within the depth, height and materials limits. Larger, double-storey or front extensions, and homes in a Redbridge conservation area, usually need planning permission from the council. Either way it must meet building regulations. We check your house and confirm the route before you spend on drawings.
Do trees near my Ilford home change the extension foundations?
They can. Homes near the mature trees around Valentines Park and Wanstead Park may sit on clay, which shrinks and swells as roots draw water. Foundations near trees on clay go deeper, and the engineer may specify a different type. Building control checks the trench depth before concrete goes in, so we plan for this at design stage.
Can a side-return extension in Ilford be built along the boundary wall?
Often, but it brings the Party Wall Act in. A trench dug close to the neighbouring house, within 3 metres and deeper than its footings, requires them to be told a month ahead, and cutting into a shared wall needs its own longer notice. Where next door objects, a surveyor's award fixes the working method, the hours and any protection their property needs.
How do we stop the middle room going dark after an Ilford side-return extension?
Put glass in the roof close to the old flank wall. Building out beside the closet wing blocks the window that used to light the room in the middle of the house, so a glazed strip or a run of rooflights along that line brings daylight back where it is needed. Part L caps the glazed area and sets insulation standards, which the design has to balance.
What stages does building control inspect on an Ilford extension?
Typically the foundation trench before concrete, the drainage before it is buried, the damp course and oversite, the steel where the back wall is opened, then insulation and the finished building. Each inspection must happen before that work is covered, so we book visits into the programme and do not pour or backfill until the inspector has seen it.
How is building control charged on an Ilford rear extension?
By floor area. In Redbridge's current building control fee schedule, extensions with a total floor area over 20m2 and not over 60m2 fall in one charging band. An Ilford side infill and rear extension together can sit close to the 20m2 line, so check the measured area before the size is fixed. The charge already includes VAT and does not change between a full plans application and a building notice.
Does joining Ilford flats back into one house count toward the Community Infrastructure Levy?
In Redbridge the Community Infrastructure Levy is triggered once a project adds more than 100 square metres of new floor area, and that holds for permitted development too. Joining existing flats creates no new floor area by itself. The levy question comes from any extension added at the same time, so measure the new floor area of the extension alone. If a large scheme gets near the threshold, relief for a homeowner's own extension has to be claimed before work starts.
Can an Ilford extension have a basement dug under it?
Redbridge Local Plan policy on basement development supports schemes that do not comprise more than one storey or sit under an existing basement. Any basement also needs a Basement Impact Assessment, sized to the proposal, covering geotechnical, structural engineering and hydrological impacts. Under an Ilford terrace that assessment covers the neighbours' shallow footings and groundwater. Commission it before the extension design is fixed, because it can change the foundations.
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