Extension plans and drawings across Mid Glamorgan
We prepare extension plans and drawings for homes across Mid 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 covered12
- Site visitFree, no obligation

Towns in Mid Glamorgan
Working in Mid Glamorgan
Towns we cover in Mid Glamorgan include Rhondda, Tonypandy, Bridgend, Merthyr Tydfil, Pontypridd, Aberdare, Caerphilly, Maesteg. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
What it costs in Mid Glamorgan
These are guide fees for Mid Glamorgan, 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 |
For a figure based on your own dimensions, use our guide-price tool.
Included in a typical project
- Measured survey of the house and garden
- Structural calculations from an engineer (full pack)
- Planning drawings: existing and proposed plans and elevations, site and location plans
- Two or three layout options to compare
- Building regulations drawings and specification
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.
Homes in conservation areas, national parks, National Landscapes (AONBs) and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
What happens next
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
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Mid Glamorgan
Do you cover all of Mid Glamorgan?
Yes, across the whole of Mid Glamorgan. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Mid Glamorgan, 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 Mid 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.
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 Mid 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.