Dormer windows in East Grinstead
We are a dormer specialist, not a general builder who occasionally does roofs — and across East Grinstead that focus shows up in the detailing.
What we build in East Grinstead
The housing stock around East Grinstead runs to Victorian and Edwardian terraces, interwar semi-detached houses and post-war bungalows — so the first question at survey is always which of those you have, because the structure underneath differs completely.
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 East Grinstead
If the property is in a conservation area or the dormer faces the road, a full planning application is needed. We prepare the drawings and handle the submission either way.
East Grinstead sits in West Sussex, 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
Glazing
Windows fitted square, sealed and drained, with escape-compliant opening lights where required.
Survey and feasibility
A specialist measures the roof, checks ridge height, span and structure, and confirms whether you are inside permitted development.
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.
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.
Popular in East Grinstead
Dormer work we are asked for most
Lead & 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 moreDormer 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 moreFAQs
Dormers in East Grinstead — FAQs
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.
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.
Does a dormer need building regulations approval?
Yes, always — permitted development covers planning, not building control. A dormer needs approval for structure, thermal performance under Part L, fire escape and protected route under Part B, and stairs under Part K if a staircase is involved. We handle the application, the inspections and the completion certificate.
What is the best roof covering for a flat dormer?
GRP fibreglass and EPDM rubber are the two we specify most. GRP cures into a single seamless laminate with bonded trims and suits small tops with several upstands. EPDM is a one-piece membrane that copes better with movement on larger spans. Both carry twenty-year guarantees; mineral felt is cheaper but has a materially shorter life.
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.
Find out what your roof will take
A free measured survey in East Grinstead tells you what is achievable, what it needs, and what it costs — before you commit to anything.