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Dormer Window Replacement in Rhondda Cynon Taf

Our teams install dormer window replacement throughout Rhondda Cynon Taf, handling structure, weatherproofing, glazing and finish as one job with one point of contact.

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.

Dormer Window Replacement — indicative geometry

Dormer Window Replacement for Rhondda Cynon Taf homes

Most of the dormer work we take on around Rhondda Cynon Taf 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.

Most dormer windows fail long before the dormer does. Rotten timber sills, blown double-glazed units, seized hinges and perished seals are all replaceable in a day or two without disturbing the cheeks or roof. We survey the surrounding timber first — there is no point putting a new frame into a rotten sub-sill, and that is where a lot of cheap replacements go wrong.

Key specification

Typical duration1–2 days per dormer
ScaffoldingTower or scaffold depending on height
Sub-sill checkTimber probed and replaced if soft
Glazing upgrade1.2 W/m²K or better
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 Rhondda Cynon Taf

Rear dormers on houses often sit inside permitted development, but the volume allowance is consumed by any previous loft or rear extension — so we check the planning history for the address before we say yes.

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 Rhondda Cynon Taf use us

We would rather tell you at survey that your ridge height will not take what you want than take a deposit and find out in week three.

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.

Other dormer work in Rhondda Cynon Taf

FAQs

Dormer Window Replacement in Rhondda Cynon Taf — FAQs

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.

What happens to my existing loft insulation?

It comes out. Insulation at ceiling-joist level is in the wrong place once the loft is a room — the thermal line moves up to the new roof and dormer build-up. We remove and dispose of the old quilt and insulate the new envelope, which is also what makes the room comfortable to use in August.

How long does a dormer take to build?

A single box or flat roof dormer is typically three to five weeks on site. A full-width rear dormer runs five to eight weeks, and an L-shaped dormer on a terrace with an outrigger is closer to seven to ten. A complete dormer loft conversion including the staircase, services and finishes is usually eight to twelve weeks from scaffold up to sign-off.

Can you build a dormer on a bungalow?

Usually yes, and bungalows often give the best results because the spans are wide and there are no party walls. The deciding factor is ridge height: you generally want at least 2.6m from the top of the ceiling joists to the underside of the ridge. We measure this at survey before committing to anything.

Can I put a dormer on the front of my house?

Front-facing dormers are not covered by permitted development and always need a full planning application. Approval depends heavily on the street scene — planners look at whether other dormers already exist on the road, and at proportion, position and materials. Hipped and pitched forms are approved far more often than flat boxes on a front elevation.

Read all frequently asked questions →

Find out what your roof will take

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

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