Dormer Loft Conversions in Gwynedd
Our teams install dormer loft conversions throughout Gwynedd, handling structure, weatherproofing, glazing and finish as one job with one point of contact.
Dormer Loft Conversions — indicative geometry
Dormer Loft Conversions for Gwynedd homes
Most of the dormer work we take on around Gwynedd 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.
A dormer loft conversion is the whole sequence: steels and a new floor structure, the dormer itself, a compliant staircase, fire-rated doors and a protected escape route, insulation to current Part L, electrics, heating and plaster. Building control sign-off is what turns loft space into habitable floor area on a survey and on a mortgage valuation — and it is the part people skip at their peril.
Key specification
| Floor area gained | 15m² – 30m² typical |
|---|---|
| Head height required | 2.2m+ over the stair landing |
| Structure | Floor steels, ridge beam, new joists |
| Compliance | Part L, Part B fire, Part K stairs |
Planning and building control in Gwynedd
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 Gwynedd 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.
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 Gwynedd
FAQs
Dormer Loft Conversions in Gwynedd — FAQs
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.
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.
Find out what your roof will take
A free measured survey in Gwynedd tells you what is achievable, what it needs, and what it costs — before you commit to anything.