Extension plans and drawings across South Glamorgan
We prepare extension plans and drawings for homes across South Glamorgan, on their own or as the first stage of a full design and build project.
- Guide priceFrom £1,100 inc VAT
- PlanningWe find the right route for you
- Towns covered4
- Site visitFree, no obligation
Who this service is for
- Projects that need a planning application or other approval
- Homeowners at the very start of a project
- Anyone who wants fixed designs before getting build prices
Working in South Glamorgan
Towns we cover in South Glamorgan include Cardiff, Barry, Penarth, Cowbridge. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
Design and approval fees for South Glamorgan
Guide fees for South Glamorgan 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 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in South Glamorgan
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
Building over or within 3 m of a public sewer needs the water company's consent before the foundations go in.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in South Glamorgan
How long does this take for a South Glamorgan home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
Will my neighbours in South Glamorgan 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.
Who do I contract with in South Glamorgan?
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.
Can I use your drawings with another builder?
Yes. Once paid for, the drawings are yours to use for your 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.
Book a free site visit in South Glamorgan
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.