Wales has its own Permitted Development rules — and many extensions, lofts and garage conversions fall inside them. Here’s how it works, what it costs when you do need it, and how Mike handles the whole thing.
⚡ Get an instant estimate 📋 Book a £60 site visit ⓘ Why a site visit? 🏴 In Chester instead?Wales sets its own planning rules — don’t rely on English websites. As a broad guide: single storey rear extensions up to 4 metres (detached) or 3 metres (semi and terraced) can often proceed under Permitted Development, subject to height limits, boundary distances and whether previous extensions have used up your allowance. Conservation areas and listed buildings play by stricter rules. When permission is needed, the householder fee in Wales is £585 plus the £149 Planning Portal charge, and councils typically decide within eight weeks. Mike assesses your rights at the site visit, designs within them wherever possible, and handles the full application when one is needed.
Mike surveys your home himself — no juniors, no outsourcing. The £60 visit fee comes off your fee when you go ahead.
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 — drawings & application handling | £750 – £1,800 by project | Mike (fixed, written) |
| Lawful Development Certificate (optional proof for PD work) | Half the planning fee | Your council |
| Planning application (if required) | £585 Wales / £548 Cheshire | Your council |
| Planning Portal service charge | £149 | Planning Portal |
| Building control (approx.) | £300 – £1,000 by project | Council / inspector |
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Mike's fee plus the council fees for planning and building control — the full professional stage, before a builder is involved. Two taps for a figure — no obligation.
Mike's fee covers the complete professional package:
Why the range? Every home is different. The lower end covers a straightforward project — a simple survey, 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're paying and what it covers. The number you agree is the number you pay.
The visit. Mike comes to your home, assesses your space and your plans, tells you whether you need planning permission, and gives you honest advice on what's possible and what it's likely to cost. The visit fee is £60.
Commission the work and it's free. If you go ahead, the full £60 is deducted from your agreed fee — so the visit effectively costs you nothing.
Work beyond the agreed scope. Anything over and above the written fee proposal — amendments after approval, planning appeals, project management — is charged separately at £60 per hour, always agreed with you first.
What it is. The fee your council charges to process a householder planning application — their planners assess your proposed extension against local and national planning policy before granting permission.
Why it's needed. Larger extensions, or ones outside the Permitted Development rules, legally need planning permission before work starts. Many smaller extensions don't need it at all — Mike will tell you which side you're on at your site visit.
How you pay. Paid directly to your council when the application is submitted — it never passes through Mike. The fee is set nationally: £585 in Wales (Flintshire, Denbighshire and Wrexham) and £548 in Cheshire West & Chester. Mike prepares, submits and handles the whole application as part of his fee. Applications go in online via the Planning Portal, which adds a £149 service charge for a householder application on top of the council fee.
What it is. The Planning Portal is the official national website where planning applications are submitted online to councils across England and Wales — it's how applications reach your council's planning department.
Why the charge. The Planning Portal is the official route applications take to your council, and it charges a service fee on any application whose council fee is over £100. Since 2026 that fee is banded by application type: Band 1 is £99 inc VAT and Band 2 is £149 inc VAT. A householder application to enlarge, improve or alter an existing dwelling — which is what an extension, loft or garage conversion is — sits in Band 2, so £149. It is charged per application submitted, so a project that goes to outline permission first and reserved matters afterwards pays it twice. You can check any application type against the Planning Portal’s published bands.
How you pay. Paid online at the point of submission, together with the council's planning fee. Mike prepares and submits the application through the Portal on your behalf — this charge just doesn't apply at all if your project is Permitted Development, because there's no application to submit.
What it is. Completely separate from planning — building control checks that the construction itself meets the Building Regulations: structure, insulation, fire safety, drainage. An inspector approves the technical drawings and visits the build at key stages.
Why it's needed. It's a legal requirement for extensions and conversions, even when no planning permission is needed. At the end you receive a completion certificate — which you'll need when you come to sell the house.
How you pay. Paid directly to the council's building control team or a private approved inspector — typically a plan charge when the drawings go in and an inspection charge when work starts. Charges vary by council and project size, which is why this line is approximate: Mike obtains an exact quote for you once the design is finalised. Not part of Mike's fee.
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, up to £734 of this comes off — Mike checks for free at your site visit.
Read more about extension plans →
Already built it without approval? Regularisation →
Guide figures only. The £60 site visit is not added to the total — 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.
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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.
Subject to conditions: single storey rear extensions up to 4m (detached) or 3m (others), many loft conversions within volume limits, most garage conversions, and porches under 3m². The conditions are the catch — height, boundaries, materials and previous extensions all count, which is why Mike checks before you commit to anything.
Councils aim to determine householder applications within eight weeks of validation. Mike prepares applications to pass validation first time — resubmissions for missing documents are where months get lost.
Yes — and anyone who tells you they haven't either hasn't submitted many or isn't being straight with you. Refusals are a normal part of planning, and every one of ours is on the public register for anyone to read. What matters is what happens next. A refusal arrives with the council's reasons attached, and most of the time those reasons are fixable — a roof line dropped, a window moved, a material changed. Mike talks to the case officer, amends the drawings and resubmits. One recent Hawarden project was refused, redrawn and approved five weeks later. That back-and-forth with planners is a large part of what you're actually paying for, and it's the reason a refusal is a delay rather than a dead end. If a proposal is genuinely borderline, Mike tells you before you spend anything.
If you build under Permitted Development, an LDC is the council’s formal confirmation it was lawful — invaluable when you sell. It costs half the planning fee and Mike can prepare it alongside your drawings.
Two taps on the estimator gives you a realistic figure. When you're ready, the £60 site visit comes off your fee if you go ahead.
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