Most people treat this as a question of budget and taste. It usually isn't. It is decided by the staircase — because building regulations set a minimum head height over it, rooflights add no height whatsoever, and on a hipped roof there is often nowhere the stair can land without one.
↓ Why the staircase decides it 📋 Book the £60 site visitEvery loft conversion runs into this sequence, and it runs in one direction only. Most people meet it backwards — they choose rooflights to avoid a planning application, then discover the stair does not comply.
A loft only counts as habitable if it meets the building regulations. That is what makes it a bedroom on a floorplan rather than an attic with a carpet.
A fixed staircase, at a legal pitch, with legal headroom over it. This is not negotiable and it is not something a builder can sign off himself.
2m over the stair as standard. A loft conversion may reduce that to 1.9m at the centre of the stair and 1.8m at the side — and no further.
Hipped roofs slope on all four sides, so the full-height band is narrow and both ends are lost. There is frequently nowhere for the stair to land.
A dormer is the only way to create height where there wasn't any. Rooflights follow the existing slope and add nothing at all.
And that is what can take the job out of Permitted Development. The planning question is decided by the staircase, several steps earlier.
The difference is at the ends of the house. A gable roof finishes with a vertical wall built up to a point. A hipped roof has a fourth roof slope there instead — which looks tidier from the street and costs you the most useful part of the loft.
Left: a gable end — a vertical wall to the apex, so the loft keeps its height right to the end of the house. Right: a hipped end — a fourth roof slope, and the height disappears before you reach the wall.
Cut through the roof and the problem is obvious. The band where you actually have standing height is narrower than people expect, and the staircase has to arrive inside it — not just the top step, but the headroom above the whole flight.
Rooflights sit in the plane of the existing roof, so they change nothing on this drawing. Only a dormer moves the line.
| Rooflights only | Dormer | |
|---|---|---|
| Adds head height | None — follows the existing slope | Yes, that is the point of it |
| Adds floor area you can stand in | No | Yes |
| Planning permission | Almost always Permitted Development | Usually PD at the rear or side; never on the road-facing slope |
| Cost | Considerably cheaper | Structural work — a significant part of the build cost |
| Works if head height is already sufficient | Yes — the right choice | Unnecessary expense |
| Works if head height is short at the stair | No, and no design will rescue it | Usually the only option |
This is why "we'll just do rooflights and avoid the planning application" is a decision that cannot be made before somebody has measured. Sometimes it is exactly right and saves you thousands. Sometimes it produces a loft that cannot legally be a bedroom.
When head height is short, the reflex is to look for a smaller staircase — an alternating tread or "paddle" stair. It is worth knowing the rules before pinning hopes on it, because they run the opposite way to what people assume.
Approved Document K requires the full 2m over an alternating tread stair — more than the 1.9m reduced allowance a conventional loft stair is given. If you are short on height, it makes the problem worse.
It is permitted as a last resort, not a design choice, and building control will expect to see why a conventional staircase was not possible.
An alternating tread stair may serve just one habitable room, plus an optional bathroom or WC. A two-bedroom loft is out.
If the measurements say rooflights will do, you are very likely in Permitted Development and there is no application, no council fee and no eight-week wait. If they say you need a dormer, the dormer is usually still Permitted Development at the rear or the side — within the volume allowance, set back from the eaves, and no higher than the existing ridge. On the roof slope facing the road, it is not.
What none of that survives is a guess. The whole chain rests on a measurement taken where the staircase has to land.
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.
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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.
2m as standard. Approved Document K allows a reduction for loft conversions where space is tight: 1.9m at the centre of the stair width, reducing to 1.8m at the side. Below that it does not comply.
Usually yes, but it more often needs a dormer, a hip-to-gable, or both. The hip removes height at the ends of the house, which is frequently where the staircase has to come up. It is the commonest reason a conversion that "obviously" only needed rooflights turns out to need more.
Rebuilding the hipped end as a vertical gable wall, so the loft keeps its full height to the end of the house. It suits semis and detached houses with hipped roofs and is often paired with a rear dormer for the biggest gain.
Only if the head height is already there. Rooflights sit in the plane of the existing roof and add no height at all. If the stair cannot achieve its headroom, rooflights do not change that.
Someone measures it. Ridge height, the position of the existing stairwell, the roof structure and where a new stair could land. That is what the £60 site visit settles, and it comes off Mike's fee if you go ahead.
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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