Building regulations for extensions in Portishead
For Portishead homeowners we handle building regulations for extensions, with fees agreed in writing before any work starts.
- Guide price in PortisheadFrom £900 inc VAT
- Approval routeFull plans or building notice
- Timescale2–5 weeks for drawings
- Postcode districtsBS20

Working in Portishead
We cover Portishead and the postcode districts BS20. The same team covers Nailsea (3 miles), Clevedon (5 miles), Keynsham (13 miles), Weston-super-Mare (13 miles), all within easy reach.
For homes towards Gloucestershire, Kingswood is around 11 miles away. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
Who this service is for
- Glass-heavy designs that need energy calculations
- Homeowners using their own builder who need the drawings
- Every extension, whatever the planning route
Building regulations approval and planning permission are separate. A design can have planning consent and still need changes to meet the regulations, which is why we draw for both together.
Design and approval fees for Portishead
Guide fees for Portishead including VAT, using our South West England factor of ×1.02. Council and building control charges are not included.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Building regulations drawings for a simple single-storey extension | £900 – £1,850 |
| Standard | Drawings plus structural calculations | £1,300 – £2,700 |
| Premium | Complex or two-storey pack with energy calculations | £2,200 – £3,900 |
Our design fee only. Building control charges are set by your council (or, in England and Wales, a registered building control approver) and quoted separately.
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in Portishead?
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.
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).
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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.
Questions answered
Will my neighbours in Portishead 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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Portishead, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with in Portishead?
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.
Who are building control?
Either your local council’s building control team or a registered building control approver. Both inspect the work and issue the completion certificate.
Full plans or building notice?
A full plans application gets the drawings checked before work starts, which we usually recommend for extensions. A building notice is quicker to submit but carries more risk if something needs changing on site.
Book a free site visit in Portishead
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.