Timber frame extensions in Watford: design, approvals and build
Our design and build teams take on timber frame extensions in Watford, from the first measured survey through planning and building control to the finished room.
- Guide price in WatfordFrom £22,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsWD1, WD2, WD17, WD18, WD23

Covering Watford
Site visits are available across Watford (WD1, WD2, WD17, WD18, WD23, WD24). Nearby, we also take on projects in Bushey (2 miles), Rickmansworth (4 miles), Borehamwood (5 miles), St Albans (7 miles).
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
Planning and approvals in Watford
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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).
What is included
- Foundations, often lighter than masonry
- Cladding, render or brick slip finish
- Frame design and structural calculations
- Breathable wall build-up with insulation
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.
How much does a timber frame extension cost in Watford?
These guide figures apply our East of England adjustment (×1.06) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Watford: £1,860 to £3,600 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £22,000 – £27,000 | £26,000 – £34,000 | £33,000 – £43,500 |
| 4 m × 5 m 20 m² | £37,000 – £45,000 | £43,000 – £56,500 | £55,000 – £72,500 |
| 5 m × 6 m 30 m² | £55,500 – £67,000 | £65,000 – £84,500 | £82,500 – £108,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
From first visit to completion
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
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 timber frame extensions
Do you cover all of Watford?
Yes. We cover Watford and the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Watford?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Watford, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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 £1,860 to £3,600 per m² including VAT.
Book a free site visit in Watford
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.