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L-Shaped Dormers in Monmouthshire and Newport

Our teams install l-shaped dormers throughout Monmouthshire and Newport, 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.

L-Shaped Dormers — indicative geometry

L-Shaped Dormers for Monmouthshire and Newport homes

Monmouthshire and Newport 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.

On a Victorian or Edwardian terrace with a rear outrigger, an L-shaped dormer wraps the main rear slope and the back addition into a single continuous structure. It is the only way to get two bedrooms plus a bathroom out of a narrow London-style terrace loft. The junction between the two arms is where these live or die — it needs a properly designed valley and a single continuous membrane.

Key specification

ConfigurationMain rear dormer + outrigger dormer
Typical footprint18m² – 30m² gained
Critical detailValley junction and continuous membrane
StructureTwo ridge beams plus valley beam
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 Monmouthshire and Newport

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 Monmouthshire and Newport 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.

If you want to know what your roof will actually take, the survey is free and there is no obligation attached to it.

Other dormer work in Monmouthshire and Newport

FAQs

L-Shaped Dormers in Monmouthshire and Newport — FAQs

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.

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.

Read all frequently asked questions →

Find out what your roof will take

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

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