Dormer windows in Carmarthen
Our teams install dormer windows and dormer loft conversions throughout Carmarthen, handling structure, weatherproofing, glazing and finish as one job with one point of contact.
What we build in Carmarthen
Most of the dormer work we take on around Carmarthen is on Victorian and Edwardian terraces, interwar semi-detached houses and post-war bungalows, where the ridge height and the position of the existing purlins set the limits.
Whether that is a single flat roof dormer to make a back bedroom usable, or a full-width rear dormer with a bedroom and en-suite, the process is the same: a free measured survey first, a fixed written price second, and nothing else until you have both in front of you.
Planning permission in Carmarthen
Getting the consent route right at the start saves months. We establish whether it is permitted development, a lawful development certificate or a full application on the first visit.
Carmarthen sits in Carmarthenshire, and local authority interpretation of the volume allowance does vary — which is why we check the planning history at your specific address rather than assuming the neighbours' dormer sets a precedent.
How the job runs
Scaffold and protection
Scaffold designed, erected and inspected. Temporary weather protection over the work area before anything is opened.
Weatherproofing
Deck, insulation, membrane or lead, cheek cladding, flashings and gutters — the dormer is weathertight from this point.
Finish and sign-off
Plaster, electrics, decoration and making good, final building control inspection and your completion certificate.
Design and consent
Measured drawings, elevations and sections. We submit the planning application or lawful development certificate and the building regulations application.
Everything is priced from a measured survey, not a phone call — which is why our quotations tend to be the ones that still hold at the end of the job. Send us the address and roughly what you are hoping to gain, and we will come back with a realistic answer rather than an optimistic one.
Popular in Carmarthen
Dormer work we are asked for most
Dormer Window Replacement
Swap tired, draughty or rotten dormer windows without touching the structure.
Learn moreSash Dormer Windows
Vertical sliding sashes sized and detailed for a dormer opening.
Learn moreLead & Zinc Dormer Roofing
Traditional code lead and standing-seam zinc for dormer roofs, cheeks and flashings.
Learn moreGable-Fronted Dormers
A pitched dormer with a vertical gable face — the classic 'dog-house' front elevation.
Learn moreL-Shaped Dormers
A rear dormer joined to a second over the outrigger — the Victorian terrace answer.
Learn moreDormer Loft Conversions
The full job — structure, dormer, stairs, insulation, plaster and building control sign-off.
Learn moreFAQs
Dormers in Carmarthen — FAQs
What is the difference between a dormer and a Velux?
A rooflight sits flush in the roof slope and gives you light without any extra height — you still have a sloping ceiling. A dormer projects out from the roof and creates vertical walls with a level ceiling behind them, so you gain genuinely usable standing space and floor area, not just daylight.
How wide can a dormer be?
Structurally, as wide as the roof — full-width rear dormers regularly run six to eight metres, carried on a steel ridge beam. The limits are usually planning volume allowances and the setbacks needed at eaves and ridge, rather than what can be built.
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.
Can a dormer include an en-suite?
Very often, yes — a full-width or L-shaped dormer usually has enough floor area for a bedroom plus a shower room. The practical constraints are getting soil and waste down to an existing stack, and whether the head height over the shower tray works. Both are settled at survey.
Can you build a dormer in winter?
Yes, with adjustments. Temporary weather protection over the scaffold lets structural work continue in most conditions. GRP roofing needs dry conditions above about 5°C to cure properly, so in a cold spell we either sequence it differently or specify EPDM, which is unaffected.
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.
Find out what your roof will take
A free measured survey in Carmarthen tells you what is achievable, what it needs, and what it costs — before you commit to anything.