House Extensions Addiscombe
Single storey rear and double storey extensions in Addiscombe, 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
GS Renovation plans and builds house extensions throughout Addiscombe, working with the bay-fronted Victorian and Edwardian terraces, rear closet wings and side returns that define the area. We have handled everything from a modest kitchen extension to a full wrap-around, foundations to finish.
In Addiscombe, 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 Addiscombe: 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.
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Addiscombe range: choose above
Side-return and rear extensions in Addiscombe
The side return beside the closet wing is the classic space to claim on an Addiscombe terrace. Filling it in widens a cramped galley kitchen into a proper open-plan kitchen-diner, and it is usually paired with a rear extension to push out towards the garden. We dig and pour the foundations, allowing for the trees around Lloyd Park and any drains running along the boundary.
Opening the back of the house into the new footprint means removing the original rear wall, so a steel beam sized by a structural engineer carries the load above. We build the walls, tie the new roof into the existing slope, install rooflights over the kitchen and fit the whole space out. Where we build up to the shared boundary, you serve the party wall notice as building owner and we build to any award.
Housing in Addiscombe
Addiscombe counts roughly 11,740 homes for Council Tax; 52% are older than 1919, 21% interwar and 27% post-war, with 45% flats and 55% houses. 41% of homes here are terraced; a rear extension on a terrace in Addiscombe digs foundations close to both neighbours, so notices to both are normal.
Extending a house in the East India Estate Conservation Area
The East India Estate Conservation Area was designated in April 2008 and lies in the Addiscombe Ward. Its management plan sets clear limits. Front extensions of street-facing buildings will not be permitted, and side extensions should be set back from the front building line by at least 1.5m at first floor level. For an Addiscombe house on the estate, that set back is the first line on the drawing. A two storey side extension flush with the front wall will not fit the plan, so the first floor steps back and the roof is designed around the step.
At the back, Croydon's conservation guidance SPD says two storey rear extensions are generally unlikely to be considered acceptable in conservation areas, and planning permission is needed for some rear extensions there. A single storey rear or side return extension is the likelier scope on the estate. Croydon will contact you to arrange a householder pre-application meeting within 20 working days of a valid submission. On a conservation area scheme those weeks are well spent, since a design agreed in outline before the application can save a refusal and a second round of drawings.
Planning and permitted development in CR0
Whether your Addiscombe extension needs a planning application or falls under permitted development depends on the property and its history. Many single storey rear extensions on these terraces proceed under permitted development within the size limits, while double storey work, anything to the side elevation or a home that has already been extended often needs a full application to Croydon Council. We advise honestly on which route applies before you commit.
Either way the build must meet building regulations, which is separate from planning and covers the foundations, the steel, insulation, drainage and fire safety. We prepare the drawings, submit to Croydon Council where permission is required, arrange a lawful development certificate where it is not, and book the building control inspections so your Addiscombe extension is signed off correctly.
Kitchen extensions in Addiscombe
75% of the houses in Addiscombe are terraced. On a terrace the kitchen extension is built out from the back, into the side return where the house has one or across the full rear width, and a steel beam takes the old back wall so the kitchen and the new room become one space. The fit-out is priced on its own page, kitchen renovation in Addiscombe; the build figures are in the table above.
Double storey extensions in Addiscombe
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 Addiscombe often needs planning permission from Croydon Council. On the 41% of homes that are terraced, the neighbours' windows usually decide the depth. The East India Estate management plan says front extensions of street-facing buildings will not be permitted (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- Brickwork and mortar matched to the existing elevation
- Wrap-around extensions and infills
- Drainage diversion and build-over agreements with the water authority
VOA Council Tax stock of properties, March 2025, for Addiscombe North, Addiscombe East and Addiscombe West. Counts rounded by the VOA.
The GS Renovation Difference in Addiscombe
Addiscombe families choose GS Renovation because one team takes the extension from the first foundation trench to the last coat of paint. We know Croydon Council's process, when permitted development applies and when it does not, how to install steel to the engineer's design and how to keep a side-return build tidy while you still live in the house. Our founder's 30+ years of experience backs it.
- Building control inspected at foundation, damp course and steel stages
- Free follow-up visit after completion if anything needs attention
- Foundation depth set after trial holes, drains and trees are checked
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George was brilliant. Lovely bloke, very reasonably priced and a perfectionist to boot. He completed our small kitchen renovation with care and great…
Giorgio is an excellent and intelligent workman, and with very reasonable prices! He installed a kitchen extractor fan in a complicated situation…
FAQ
Frequently Asked Questions about House Extensions Addiscombe
Can I get a fixed price for house extensions at a CR0 address?
A fixed price for house extensions at a CR0 address is possible wherever the scope can be pinned down at survey. GS Renovation quotes most Addiscombe jobs as a fixed project price within £2,000 to £2,800 per m² for a rear extension (indicative), covering labour, materials and building regulations approval from foundations to completion. Where an unknown sits behind plaster, it is named before starting, and any variation is agreed in writing.
Will my Addiscombe rear extension need planning permission or is it permitted development?
It depends on the size and your property's history. A single storey rear extension on an Addiscombe terrace often falls under permitted development within the depth and height limits, but larger, double storey or side extensions usually need a planning application to Croydon Council. We assess your specific house first and either submit the application or secure a lawful development certificate, then build to building regulations.
Will the trees near Lloyd Park affect my Addiscombe extension foundations?
They can. Tree roots draw water from clay soils, making the ground shrink in dry spells and swell again, so building control sets deeper foundations when trees stand within range. On CR0 streets near Lloyd Park the engineer notes the species and distance of nearby trees, including next door's, and trial holes confirm the depth before design.
Will a side infill make the middle room of my Addiscombe terrace dark?
It can, because the infill covers the window that lit it. The new roof usually slopes down from the party wall into the existing closet-wing wall, and rooflights set close to the house bring daylight back to the middle of the plan. Glazing in the roof affects the insulation calculation, so the rooflight size is agreed at design stage in an Addiscombe terrace.
When does the back wall of my Addiscombe house come out for the extension?
Near the end, once the extension is weathertight. The new foundations, walls and roof go up against the existing rear wall while the house stays sealed. Only then is the house propped, the rear wall cut out, and the steel set on its padstones for building control to inspect. That keeps an Addiscombe house open to the weather only briefly.
Does digging near my neighbour matter for an Addiscombe extension?
Yes, when the trench goes deeper than their foundations. On narrow Addiscombe plots the new footing often runs right beside next door, and a dig within 3 metres of their house that goes lower than its own footings calls for a month's written notice under the 1996 Act. Your neighbour then agrees, or dissents so that appointed surveyors settle an award; serving it early keeps the start date.
Will an Addiscombe side return extension be charged Croydon's CIL?
No. Croydon states that CIL is not charged on extensions or other home adaptations, and a side return infill or rear extension to an Addiscombe terrace is exactly that. The per square metre rates Croydon publishes are not part of an extension budget. What does belong in it is the party wall process with the neighbours, the drainage survey and the building control application, which together set the start date more than any levy.
What should a Croydon planning application for an Addiscombe extension include?
Start from the current list. Croydon's Local Validation checklist of documents required with planning applications was updated in May 2026, so drawings prepared against an older list should be checked before submission. For a house in the East India Estate Conservation Area, it helps to show how the design respects the management plan, including the front building line and the set back at first floor. An invalid application does not start the decision period, so the checklist is worth reading first.
Do trees in an East India Estate garden affect an Addiscombe extension?
Yes, on paper as well as underground. Croydon requires at least 6 weeks' notice to the council before works to any tree in a conservation area, and the East India Estate Conservation Area is one. A tree that needs cutting back for scaffold, or roots that have to be pruned for a trench, add those 6 weeks to the programme. A tree within reach of the new footings can also push them deeper, which the structural engineer we appoint sets once the species and distance are known.
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