Pitched roof extensions in Monmouth: design, approvals and build
If you live in Monmouth and want more space without moving, a pitched roof extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in MonmouthFrom £20,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsNP25
Covering Monmouth
We cover Monmouth and the postcode districts NP25. Nearby, we also take on projects in Chepstow (11 miles), Abergavenny (12 miles), Pontypool (15 miles), Cwmbran (16 miles).
In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
What we take care of
- Vaulted ceilings or flat ceilings with storage above
- Insulation to current building regulations
- Lead or proprietary flashings to the main wall
- Roof design matched to the existing pitch and tiles
- Roof windows positioned for light and ventilation
Matching tiles is harder than it sounds. We source reclaimed or closest-match tiles where the originals are no longer made and agree samples with you before ordering.
Planning rules that apply in Monmouth
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. Wales has its own building regulations and approved documents; the council or a registered building control approver checks the plans, inspects the work and issues a completion certificate.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Guide prices for Monmouth
Labour and material costs vary across the UK, so for Monmouth we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Monmouth: £1,720 to £3,260 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £20,500 – £24,000 | £23,500 – £31,000 | £30,500 – £39,500 |
| 4 m × 5 m 20 m² | £34,000 – £40,000 | £39,500 – £51,500 | £51,000 – £65,500 |
| 5 m × 6 m 30 m² | £51,500 – £60,000 | £59,500 – £77,000 | £76,500 – £98,000 |
Try the guide-price tool to see a range for your own size and finish.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Pitched roof extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Monmouth, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Monmouth be involved?
If a planning application is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do I need building regulations approval in Monmouth?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I have a vaulted ceiling?
Yes. A vaulted ceiling with roof windows is one of the main reasons to choose a pitched roof. It needs insulation between and under the rafters to meet the building regulations.
How much does a pitched roof extension cost?
Our guide range is about £1,720 to £3,260 per m² including VAT, a little more than a flat roof because of the roof structure and tiles.
Book a free site visit in Monmouth
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.