Box Dormers in Bristol
From the first measured survey to the completion certificate, we run box dormers projects in Bristol as a single, managed piece of work.
Box Dormers — indicative geometry
Box Dormers for Bristol homes
Bristol 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.
A box dormer is the plainest form there is: two cheeks, a flat or very shallow top, and a flat front. There is nothing clever about it, which is precisely the point — fewer junctions means fewer places to leak, and a shorter programme on site. Most single-room dormers on post-war housing are box dormers whether or not anyone calls them that.
Key specification
| Typical projection | 1.5m – 3.5m wide |
|---|---|
| Depth | 1.8m – 3.0m into the roof |
| Roof finish | GRP, EPDM or felt |
| Cheek finish | Tile-hung, GRP or vertical cladding |
Planning and building control in Bristol
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 Bristol 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.
The quickest route is a photograph of the rear elevation over WhatsApp — we can usually tell you what is feasible before anyone visits.
Other dormer work in Bristol
FAQs
Box Dormers in Bristol — FAQs
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.
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.
Find out what your roof will take
A free measured survey in Bristol tells you what is achievable, what it needs, and what it costs — before you commit to anything.