Measured survey, planning application and full building regulation drawings for single and two storey extensions — across Deeside, Flintshire, Chester, Wrexham and Denbighshire. One fixed written fee, from £750.
⚡ Get an instant estimate 📋 Book a £60 Initial Site Appraisal Meeting ⓘ Why an Initial Site Appraisal Meeting?An extension lives or dies on its drawings. They decide whether the council says yes, whether your builder can quote accurately, and whether the build matches what you imagined. Mike Williams has produced extension drawings across North Wales and the border for 25 years — established 2010, registered at Companies House, every application publicly checkable on the council planning portals.
Once your fee is agreed, Mike returns and measures the house himself — no juniors, no outsourcing. This is the second visit; the earlier £60 Initial Site Appraisal Meeting comes off your fee.
Scaled drawings of your home as it is and as it will be — the documents your planning application stands on.
Prepared, submitted and handled for you — or confirmation you don't need one under Permitted Development, which saves you the council fee entirely.
The technical pack — structure, insulation, fire safety, drainage — that building control approves and your builder prices from.
Mike works to a fixed written fee, agreed before any work begins. Council fees are separate and paid directly — never through Mike.
| Item | Typical cost | Paid to |
|---|---|---|
| Mike's fee — single storey extension | £750 – £1,400 | Mike (fixed, written) |
| Mike's fee — two storey extension | £950 – £1,800 | Mike (fixed, written) |
| Planning application (if required) | £585 Wales / £548 Cheshire | Your council |
| Planning Portal service charge | £149 | Planning Portal |
| Building control (approx.) | £650 – £2,000 | Council / inspector |
Or just use it right here ↓
Pick your project and see Mike's fee. Everything else you might pay is listed underneath, so you can see who gets what.
Mike’s fee covers the complete design and approvals stage:
Why the range? Every home is different. The lower end covers a straightforward project — standard drawings, no planning application needed. The higher end covers larger or more complex work — a full planning application, more detailed drawings, or structural design to coordinate.
Before any work begins, Mike gives you a detailed written fee proposal — so you know exactly what you are paying and what it covers. The number you agree is the number you pay.
Only if planning permission is needed. Wales charges £585 for a householder application and Cheshire West & Chester £548 — the fee is set nationally, so it does not vary between Welsh councils. Paid directly to your council, never through Mike.
The service charge for submitting a planning application online. It also only applies if permission is needed, and it is charged per application submitted.
This one always applies, permission or not. It is calculated on floor area and subject to the final design — smaller projects sit toward the lower figure, larger ones toward the higher. Paid to the council's building control team or a private approved inspector, never through Mike, and he gets you an exact quote once the design is finalised.
Design and approvals only. This is what it costs to get your project drawn and approved — it does not include your builder’s costs for the actual building work.
If your project turns out to be Permitted Development, you will not need to pay the council planning fee or the Planning Portal charge, a saving of up to approximately £734. Mike checks this at the Initial Site Appraisal Meeting.
Read more about extension plans →
Already built it without approval? Regularisation →
Guide figures only. The £60 Initial Site Appraisal Meeting is not added to these figures — it comes off Mike's fee when you commission the work. Council fees correct at July 2026; building control charges vary by council and project — full details in the FAQs. Mike confirms everything in a written fee proposal before any work begins.
Or have Mike email this estimate to you — no obligation.
✅ Sent — your estimate is on its way. No obligation.
Couldn't send just now — call Mike on 07703 786 460 or email [email protected].
£60, and it comes off your fee when you go ahead. Mike comes to the property to understand the scope of what you want to do and advise you accordingly — then sends a written fixed fee afterwards.
Every planning application Deeside Architectural Design submits goes onto the council's public register — under the practice name, with the decision attached, permanently. It's free to search and it isn't curated by us. What the register cannot show you is the other half of the work: the projects that qualified as Permitted Development, needed no application at all, and saved the client the council fee. Those leave no public trace. So the number below is the part you can check — not the whole of it. Before you decide whether the fee above is worth paying, go and read it.
Submitted to Flintshire County Council under Deeside Architectural Design since 2010 — every one searchable, with its decision attached.
Many projects qualify as Permitted Development, need no application, and never reach the register. The 165 is the work that required permission — not the count of jobs done.
Deeside Architectural Design Limited, incorporated January 2010, and 25 years of drawings behind it. Companies House no. 07128221.
Open Flintshire's planning register, put Deeside Architectural in the Agent field, and read every decision — including the ones that didn't go our way.
Search Flintshire's planning register →
Figures taken from Flintshire County Council's public planning register, August 2026.
Everything above is about work you are planning. There is a second situation Mike handles, and it catches people out years later: an extension that was built without building regulations approval. It sits there causing nobody any trouble — until you come to sell. Then the buyer's solicitor asks for the certificate, there isn't one, and the sale stops dead.
It is fixable, and it is a different job from the one priced above. Mike acts as your consultant through regularisation: the Initial Site Appraisal Meeting, the drawings and statements building control need, the meeting with the building control officer at the property, and the coordination on any work required before the certificate can be issued. From £997 to £1,500, depending on what was built and what it takes to satisfy the council.
If there is any chance the extension at your property was never signed off, deal with it now rather than at the point of sale, when you have no time and no bargaining power.
Sometimes you may not need it — a single storey rear extension can fall under Welsh Permitted Development (up to 4m beyond the rear wall, whatever the house type, and subject to a long list of conditions). Mike tells you which side you're on at the Initial Site Appraisal Meeting, before any fees are committed. If permission is needed, he handles the whole application.
Survey to submitted application is typically 2–4 weeks depending on complexity. Councils then take around 8 weeks to determine a householder application. Building regulation drawings usually follow while planning is being decided, so no time is wasted.
If you need more than one extra room, two storey almost always wins on cost per square metre — the foundations and roof are being built either way. If the goal is a bigger kitchen or open-plan living, a well-designed single storey can be transformational. Mike will talk you through both honestly at the Initial Site Appraisal Meeting.
Yes — they're the same building-regulation-standard drawings every builder and building control body works from. Good builders prefer them: a fixed scope protects their quote as much as your budget.
Two taps on the estimator gives you a realistic figure. When you're ready, the £60 Initial Site Appraisal Meeting comes off your fee if you go ahead.
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