Mitcham timber frame extensions, designed and built
A timber frame extension in Mitcham starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in MitchamFrom £27,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsCR4, SM4, SM5, SW16, SW17
Planning and approvals in Mitcham
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
The planning position for a specific Mitcham address depends on its history and any designations, which is why we check it at the first visit.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Local to Mitcham
Across CR4, SM4, SM5, SW16, SW17, SW19, we can visit, measure and advise. Nearby, we also take on projects in Morden (1 mile), Tooting (2 miles), Wimbledon (2 miles), Streatham (2 miles).
For homes towards Surrey, Ewell is around 5 miles away. London's housing is dominated by Victorian and Edwardian terraces, many with a rear outrigger and a side return, and 1930s semis in the outer boroughs. Conservation areas are common, so the planning check comes first.
What is included
- Frame design and structural calculations
- Fire and acoustic details where needed
- Breathable wall build-up with insulation
- Foundations, often lighter than masonry
- Cladding, render or brick slip finish
Moisture is the enemy of any timber building. We design ventilated cladding cavities, breather membranes and a proper damp-proof course height, and keep the frame dry during construction.
What should I budget for a timber frame extension in Mitcham?
Prices below are for Mitcham, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Mitcham: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £27,000 – £33,000 | £31,500 – £41,500 | £40,500 – £53,500 |
| 4 m × 5 m 20 m² | £45,500 – £55,000 | £53,000 – £69,000 | £67,500 – £88,500 |
| 5 m × 6 m 30 m² | £68,000 – £82,000 | £79,500 – £103,500 | £101,000 – £133,000 |
Try the guide-price tool to see a range for your own size and finish.
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Mitcham
Will my neighbours in Mitcham 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.
How long does a timber frame extension take to build in Mitcham?
On site, typically 8 to 14 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Do I need building regulations approval in Mitcham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Does a timber frame extension need planning permission?
The same planning rules apply as for any extension. If the cladding looks different from the house, permitted development’s matching-materials condition may mean an application is needed.
Is timber frame cheaper than brick?
It is similar overall. The frame can save time on site, but the cladding choice has a big effect on cost. Our guide range is about £2,280 to £4,420 per m² including VAT.
Book a free site visit in Mitcham
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.