Full-Width Rear Dormers in County Antrim
County Antrim homeowners come to us for full-width rear dormers that are properly detailed at the junctions — because that is where dormers succeed or fail.
Full-Width Rear Dormers — indicative geometry
Full-Width Rear Dormers for County Antrim homes
The housing stock around County Antrim 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.
A full-width rear dormer runs from party wall to party wall, squaring off the entire rear slope. On a standard terrace or semi it typically converts 12–18m² of crawl space into full-height room — enough for a double bedroom and an en-suite. Set back 200mm from the eaves and 500mm below the ridge, it usually falls inside permitted development on a house that has not been extended before.
Key specification
| Typical projection | 4.0m – 8.0m wide |
|---|---|
| Set-back | 200mm from eaves, 500mm below ridge |
| Structure | Steel ridge beam plus floor steels |
| Roof finish | GRP, EPDM or single-ply membrane |
Planning and building control in County Antrim
Whether you need planning permission or a lawful development certificate depends on the elevation, the volume already used and the local authority's Article 4 position — all of which we confirm before design work starts.
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 County Antrim use us
One quotation covers scaffold, structure, weatherproofing, glazing, plastering and sign-off. You are not coordinating four trades who each blame the last one.
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 County Antrim
- Dormer Window Installation in County Antrim
- Timber Dormer Windows in County Antrim
- Conservation Dormer Windows in County Antrim
- Lead & Zinc Dormer Roofing in County Antrim
- Pitched Roof Dormers in County Antrim
- Shed Dormers in County Antrim
- Eyebrow Dormers in County Antrim
- Bungalow Dormer Conversions in County Antrim
FAQs
Full-Width Rear Dormers in County Antrim — FAQs
Why is my dormer leaking?
In our experience the window itself is the cause less than a fifth of the time. Far more often it is the apron flashing at the dormer front, the lead soakers where the cheeks meet the roof slope, the back gutter behind a pitched dormer, or a split at an upstand in the flat covering. Water then tracks along a rafter and appears somewhere else entirely, which is why we trace the path before quoting.
Will a dormer add value to my house?
A properly built and signed-off dormer conversion adding a bedroom and bathroom typically returns a meaningful share of its cost in value, and more in areas where floor space is scarce. The building control completion certificate is what makes the space count as habitable floor area on a valuation — without it, surveyors will not include it.
Is scaffolding included in the price?
Yes. Every quotation we issue includes scaffold design, erection, weekly inspection, hire for the programme and dismantling. Scaffold appearing as an extra afterwards is one of the more common complaints about dormer work, so we price it in from the start.
How wide can a dormer be?
Structurally, as wide as the roof — full-width rear dormers regularly run six to eight metres, carried on a steel ridge beam. The limits are usually planning volume allowances and the setbacks needed at eaves and ridge, rather than what can be built.
What guarantees do you provide?
Structural work carries a ten-year guarantee, GRP and EPDM flat roofing twenty years, windows ten years on frames and sealed units, and lead and zinc work is covered for workmanship for ten years. You also receive the building control completion certificate, which is the document that actually matters when you sell.
Find out what your roof will take
A free measured survey in County Antrim tells you what is achievable, what it needs, and what it costs — before you commit to anything.