Annexe extensions in Croydon
Croydon homeowners can use us for the whole annexe extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in CroydonFrom £71,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsCR0, CR7, CR9, SE19, SE25
Planning rules that apply in Croydon
In England an annexe that stays part of the household and connects to the house is assessed as an extension, but its size usually takes it beyond permitted development, so a householder application describing the ancillary use is the normal route.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Croydon
Site visits are available across Croydon (CR0, CR7, CR9, SE19, SE25, SM6). We also work in nearby South Croydon (1 mile), South Norwood (2 miles), Upper Norwood (2 miles), Norbury (2 miles).
Just over the Surrey border, Banstead is about 6 miles away. In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
How much does an annexe extension cost in Croydon?
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Croydon: £2,600 to £4,940 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £71,500 – £89,500 | £78,000 – £97,500 | £97,500 – £123,500 |
| One-bedroom annexe 35 m² | £91,000 – £114,000 | £109,000 – £136,500 | £136,500 – £173,000 |
| Larger annexe 45 m² | £117,000 – £146,500 | £140,000 – £175,500 | £175,500 – £222,500 |
For a figure based on your own dimensions, use our guide-price tool.
What is included
- Planning application describing ancillary use
- Separate or shared heating and hot water
- Kitchenette, shower room and bedroom finish
- Fire separation and alarms to building regulations
- Design for accessibility: level thresholds, wider doors, walk-in shower
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about annexe extensions
How long does an annexe extension take to build in Croydon?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Will my neighbours in Croydon be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Who do I contract with for an annexe extension in Croydon?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will an annexe affect council tax?
It can. Some annexes are assessed separately for council tax, with discounts or exemptions in some cases when occupied by a relative. Check with the Valuation Office Agency (England and Wales), your local assessor (Scotland) or Land & Property Services (Northern Ireland).
How much does an annexe extension cost?
Our guide range is about £2,600 to £4,940 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £109,000 to £136,500 at standard spec in Croydon.
Book a free site visit in Croydon
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.