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Dormer Window Installation in West Sussex

From the first measured survey to the completion certificate, we run dormer window installation projects in West Sussex as a single, managed piece of work.

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 Installation — indicative geometry

Dormer Window Installation for West Sussex homes

West Sussex 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.

Installing into a dormer is not installing into a wall. The opening sits in a lightweight timber frame that may have moved, the sill needs a positive fall and a proper drip, and the head has to be flashed back under the cheek cladding. Getting a dormer window in square, sealed and draining is a different skill from a ground-floor replacement.

Key specification

Frame materialsuPVC, timber, aluminium or composite
GlazingA-rated double or triple glazed
SillPositive fall with stooled ends and drip
SealingCompressed foam tape plus low-modulus silicone
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 West Sussex

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 West Sussex 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.

Book the survey, get the fixed written price, and decide in your own time. Nothing about that process commits you to anything.

Other dormer work in West Sussex

FAQs

Dormer Window Installation in West Sussex — FAQs

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.

Do you handle the planning application?

Yes. We prepare measured drawings, elevations and sections, submit the application or the lawful development certificate, and deal with the case officer's queries. On conservation and listed work we also put together the heritage justification the application needs.

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.

Do you work on listed buildings and in conservation areas?

Yes. That work is detail-led: matching sightlines, glazing bar widths, cill projections and cheek finishes to what survives, and specifying timber, lead and natural slate rather than modern equivalents. We prepare the drawings and heritage statement for listed building consent alongside the planning application.

Read all frequently asked questions →

Find out what your roof will take

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

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