Extension plans and drawings across Carmarthen
We prepare extension plans and drawings for homes in Carmarthen, as a stand-alone service or as the first stage of a design and build project.
- Guide price in CarmarthenFrom £1,100 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsSA31
Will the council need to approve it?
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 Carmarthen address depends on its history and any designations, which is why we check it at the first visit.
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.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Design and approval fees for Carmarthen
These are guide fees for Carmarthen, adjusted for Wales (×0.93) and including VAT. Council application and inspection fees are paid separately.
| 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
- Building regulations drawings and specification
- Measured survey of the house and garden
- Planning drawings: existing and proposed plans and elevations, site and location plans
- Structural calculations from an engineer (full pack)
- 3D views to check the look and the light (full pack)
- Two or three layout options to compare
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.
Covering Carmarthen
Postcode districts we cover around Carmarthen include SA31. We also work in nearby Llanelli (13 miles), Ammanford (14 miles), Haverfordwest (29 miles), Pembroke Dock (29 miles).
For homes towards West Glamorgan, Gorseinon is around 17 miles away. 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.
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
We visit your Carmarthen home, measure up, talk through what you want and check the planning position.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions answered
Do you cover all of Carmarthen?
Yes. We cover Carmarthen and the surrounding parts of Dyfed. Site visits are free and there is no obligation.
Will my neighbours in Carmarthen be involved?
If a planning application is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does this take for a Carmarthen home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
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.
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.
Book a free site visit in Carmarthen
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.