Extension plans and drawings in Cardiff
We prepare extension plans and drawings for homes in Cardiff, as a stand-alone service or as the first stage of a design and build project.
- Guide price in CardiffFrom £1,100 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsCF5, CF10, CF11, CF14, CF23
Fees in Cardiff
Guide fees for Cardiff including VAT, using our Wales factor of ×0.93. Council and building control charges are not included.
| 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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Working in Cardiff
Site visits are available across Cardiff (CF5, CF10, CF11, CF14, CF23, CF24). Neighbouring towns we cover include Penarth (3 miles), Barry (7 miles), Cowbridge (12 miles).
Caerphilly, in Mid Glamorgan, is roughly 7 miles from Cardiff and also on our list. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
When it helps
- Anyone who wants fixed designs before getting build prices
- Homeowners at the very start of a project
- Projects that need a planning application or other approval
Do I need planning permission in Cardiff?
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.
In a conservation area, national park, National Landscape or 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.
Building over or within 3 m of a public sewer needs the water company's consent before the foundations go in.
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).
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
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Cardiff
Do you cover all of Cardiff?
Yes. We cover Cardiff and the surrounding parts of South Glamorgan. Site visits are free and there is no obligation.
Who do I contract with in Cardiff?
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.
Will my neighbours in Cardiff 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 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.
Can I use your drawings with another builder?
Yes. Once paid for, the drawings are yours to use for your project.
Book a free site visit in Cardiff
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.