Timber frame extensions for homes in Horsham
Our design and build teams take on timber frame extensions in Horsham, from the first measured survey through planning and building control to the finished room.
- Guide price in HorshamFrom £23,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsRH12, RH13

Working in Horsham
We cover Horsham and the postcode districts RH12, RH13. Nearby, we also take on projects in Crawley (7 miles), Haywards Heath (11 miles), Burgess Hill (11 miles), East Grinstead (15 miles).
For homes towards Surrey, Horley is around 11 miles away. The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
Planning rules that apply in Horsham
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.
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.
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 we take care of
- Breathable wall build-up with insulation
- Foundations, often lighter than masonry
- Fire and acoustic details where needed
- 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 Horsham?
Labour and material costs vary across the UK, so for Horsham we use our South East England factor (×1.12). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Horsham: £1,960 to £3,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £23,500 – £28,500 | £27,500 – £36,000 | £34,500 – £46,000 |
| 4 m × 5 m 20 m² | £39,000 – £47,500 | £45,500 – £59,500 | £58,000 – £76,500 |
| 5 m × 6 m 30 m² | £58,500 – £71,000 | £68,500 – £89,500 | £87,000 – £114,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
How the project works
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
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.
Timber frame extension questions answered
Do you cover all of Horsham?
Yes. We cover Horsham and the surrounding parts of West Sussex. Site visits are free and there is no obligation.
Who do I contract with for a timber frame extension in Horsham?
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.
Do I need building regulations approval in Horsham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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 £1,960 to £3,810 per m² including VAT.
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.
Book a free site visit in Horsham
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.