Extension plans and drawings across Swansea
We prepare extension plans and drawings for homes in Swansea, as a stand-alone service or as the first stage of a design and build project.
- Guide price in SwanseaFrom £1,100 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsSA1, SA2, SA3, SA5, SA6
Local to Swansea
Across SA1, SA2, SA3, SA5, SA6, SA7, we can visit, measure and advise. The same team covers Clydach (5 miles), Briton Ferry (5 miles), Gorseinon (5 miles), Neath (7 miles), all within easy reach.
Llanelli, in Dyfed, is roughly 10 miles from Swansea and also on our list. Welsh housing ranges from stone terraces in the valleys to render-and-slate houses and modern estates, and the Welsh planning rules differ from England's in several places.
Planning and approvals in Swansea
In Wales the routes are permitted development (a lawful development certificate is available), or a householder planning application to the council. Wales has no prior approval scheme for larger rear extensions, and fees are set by the Welsh Government.
The planning position for a specific Swansea address depends on its history and any designations, which is why we check it at the first visit.
Building over or within 3 m of a public sewer needs the water company's consent before the foundations go in.
Building regulations approval is separate from planning. Wales has its own building regulations and approved documents; the council or a registered building control approver checks the plans, inspects the work and issues a completion certificate.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
What it costs in Swansea
Fees below are our Swansea guide (×0.93, the Wales factor), including VAT. Council and building control fees are extra.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Measured survey and planning drawings | £1,100 – £2,050 |
| Standard | Planning drawings plus building regulations drawings | £2,000 – £3,550 |
| Premium | Full pack with structural calculations and 3D visuals | £3,150 – £5,150 |
Try the guide-price tool to see a range for your own size and finish.
What is included
- Two or three layout options to compare
- Structural calculations from an engineer (full pack)
- Measured survey of the house and garden
- 3D views to check the look and the light (full pack)
- Building regulations drawings and specification
- Planning drawings: existing and proposed plans and elevations, site and location plans
The most expensive changes are the ones made after the steel is ordered. A good design stage settles layout, heights, glazing and services on paper, so the build price is firm.
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
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.
Common questions in Swansea
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Swansea, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does this take for a Swansea home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
Do you cover all of Swansea?
Yes. We cover Swansea and the surrounding parts of West Glamorgan. Site visits are free and there is no obligation.
Do I need an architect?
Not necessarily. For most extensions an experienced designer or architectural technologist is enough. For listed buildings or complex sites an architect’s input can help.
How much do extension plans cost?
Our design packs range from about £1,100 to £5,150 including VAT, from planning drawings only to a full pack with building regulations drawings, structural calculations and 3D views. Council fees are separate.
Book a free site visit in Swansea
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.