Timber frame extensions for homes in Portsmouth
Our design and build teams take on timber frame extensions in Portsmouth, from the first measured survey through planning and building control to the finished room.
- Guide price in PortsmouthFrom £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 districtsPO1, PO2, PO3, PO4, PO5

Planning rules that apply in Portsmouth
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
When a timber frame extension makes sense
- Homeowners who want strong energy performance
- Sites where weight or speed matters
- Contemporary designs with timber or board cladding
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.
Covering Portsmouth
Postcode districts we cover around Portsmouth include PO1, PO2, PO3, PO4, PO5, PO12. The same team covers Gosport (2 miles), Fareham (5 miles), Havant (6 miles), Waterlooville (6 miles), all within easy reach.
Just over the Isle of Wight border, Ryde is about 6 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.
Timber frame extension prices in Portsmouth
Prices below are for Portsmouth, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Portsmouth: £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 |
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
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Timber frame extension questions answered
Do I need building regulations approval in Portsmouth?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a timber frame extension take to build in Portsmouth?
On site, typically 8 to 14 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Will my neighbours in Portsmouth 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.
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 £1,960 to £3,810 per m² including VAT.
Book a free site visit in Portsmouth
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.