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Cat Slide Dormers in Carmarthenshire

If you are weighing up cat slide dormers in Carmarthenshire, we survey the roof, tell you what is actually achievable, and price it properly before anyone commits.

Free measured surveyA specialist visits, measures and tells you what the roof will and will not take.
Fixed written priceOne quotation covering structure, scaffold, weatherproofing, glazing and making good.
Building control managedWe submit, book the inspections and hand you the completion certificate.
Insured and guaranteed£5m public liability, ten-year structural and twenty-year flat roofing guarantees.
Nationwide coverageDirectly employed and vetted specialist teams across England, Wales, Scotland and Northern Ireland.

Cat Slide Dormers — indicative geometry

Cat Slide Dormers for Carmarthenshire homes

Carmarthenshire is a mix of Victorian and Edwardian terraces, interwar semi-detached houses and post-war bungalows, and each of those wants a different dormer form — which is why we survey before quoting rather than pricing off a photograph.

A cat slide (or 'sweeping') dormer lets the main roof plane run on below the dormer sill, so the dormer appears to emerge from the roof rather than to be planted on it. It is a rural and cottage idiom, and it works beautifully on long, low roofs where a box dormer would look brutal. Detailing at the sill and the sweeping valley is the whole job.

Key specification

Typical width1.2m – 3.0m
SweepMain roof continues below sill line
Roof finishPlain tile, slate or pantile
Critical detailSwept valley and sill flashing
Indicative guide prices. Our online tool gives a realistic range in about a minute — pick your dormer type, width, finish and scope. Get an indicative price →

Planning and building control in Carmarthenshire

We run the permitted development test on your specific property: set-back from the eaves, height against the ridge, volume allowance and whether an Article 4 direction applies locally.

Building regulations approval is separate and always required. We submit the application, book the inspections around the programme and hand you the completion certificate at the end — the document a buyer's surveyor will ask to see.

Why homeowners in Carmarthenshire use us

We only do dormers. That sounds like a limitation until you have watched a general builder improvise a back gutter on a wet Thursday.

The quickest route is a photograph of the rear elevation over WhatsApp — we can usually tell you what is feasible before anyone visits.

Other dormer work in Carmarthenshire

FAQs

Cat Slide Dormers in Carmarthenshire — FAQs

Can you convert an existing Velux loft to a dormer?

Yes, and it is usually a shorter job than starting from scratch because the floor, staircase and services already exist. We verify the existing floor structure and any previous building control approval first, then cut and form the dormer into the finished room. Expect the room to be out of use for three to five weeks.

How disruptive is a dormer build?

Less than people expect, because most of the work happens above your ceilings and is reached from the scaffold. The noisy phases are opening up and installing steels, typically two to four days. Once the staircase is cut in there is dust and traffic through the house, and we sheet and protect the route for that period.

Do dormer windows need to be fire escape windows?

In a loft conversion, at least one window in each habitable room generally needs to meet escape requirements — a clear opening of at least 0.33m², minimum 450mm in both height and width, with the bottom of the opening between 800mm and 1100mm above floor level. We specify the opening lights to meet this as standard.

Do I need planning permission for a dormer window?

Rear dormers on a house often fall under permitted development, provided the dormer is set at least 200mm back from the eaves, sits below the ridge line, uses materials similar in appearance to the existing house, and stays within the volume allowance — 40m³ for a terrace, 50m³ for a semi or detached. Front-facing dormers, flats and maisonettes, listed buildings, conservation areas and any property with an Article 4 direction all need a full planning application. We check the constraints on your specific address before we quote.

Will my roof be open to the weather?

No. The roof is only opened once the scaffold, temporary weather protection and materials are all on site, and the dormer is made weathertight — structure, deck, membrane and temporary glazing — before the crew leaves at the end of the opening-up phase. We do not open a roof on a Friday afternoon.

Read all frequently asked questions →

Find out what your roof will take

A free measured survey in Carmarthenshire tells you what is achievable, what it needs, and what it costs — before you commit to anything.

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