First-floor extensions in Haverfordwest
Thinking about a first-floor extension in Haverfordwest? We design it, take it through the approvals it needs and build it, with one team responsible from the first visit to the final certificate.
The basics for Haverfordwest at a glance.
- Postcode districts
- SA61, SA62 and SA63
- County / area
- Dyfed, Wales
- Price region
- Wales
- Guide price
- £23,000–£33,500 (£1,660–£2,390 per m²)
- Approval route
- It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
- Nearest towns
- Steynton (5.4 miles), Neyland (6.4 miles), Milford Haven (6.7 miles)
- Distance to Llanelli
- about 35.5 miles
- First visit
- Free, no obligation
About a first-floor extension
A first-floor extension suits you if your house already has a single-storey extension and you need more space upstairs. You get a structural check of the existing walls and foundations, a design that ties the new floor into the house, the approvals your nation needs, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.
We cover Haverfordwest (SA61, SA62 and SA63) and the places around it, including Steynton (5.4 miles), Neyland (6.4 miles) and Milford Haven.
What it costs in Haverfordwest
Using our Wales rates, a first-floor extension with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £23,000–£33,500, including VAT. Bigger or more glazed designs cost more per m². We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| Spec | Per m² | 4 m × 3.5 m of new first-floor space (14 m²) |
|---|---|---|
| Essential | £1,520–£2,200 per m² | £21,500–£31,000 |
| Standard | £1,660–£2,390 per m² | £23,000–£33,500 |
| Premium | £1,990–£2,870 per m² | £28,000–£40,000 |
Planning and building regulations in Haverfordwest
In Wales, a first floor over a rear extension can be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 10.5 m from the rear boundary, with the ground floor within 4 m. Over a side extension, the 10.5 m, 1 m set-back and 50% width tests apply. Otherwise a householder application costs £585.
Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.
Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).
Design points for Haverfordwest homes
Escape and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and 450 mm high, with the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs.
Replacing the flat roof
The existing roof usually comes off and is replaced by a new first-floor structure. The room below is exposed for a short time, so we plan temporary weatherproofing and sequence the work to keep the kitchen or living room usable for as long as possible.
How we'd run your project
Understand the brief
At your home in Haverfordwest we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Wales before drawing in detail.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about first-floor extensions in Haverfordwest
How much does a first-floor extension cost in Haverfordwest?
Our guide for Wales, which covers Haverfordwest, is £1,660–£2,390 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £23,000–£33,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Who handles building regulations for a project in Haverfordwest?
We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
Which postcodes do you cover around Haverfordwest?
We cover Haverfordwest (SA61, SA62 and SA63) and nearby places including Steynton, Neyland and Milford Haven, plus the rest of Dyfed. The first site visit is free.
What happens to the room below while the first floor is built?
The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.
Can I build on top of my existing single-storey extension?
Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original building control approval and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.
Nearby
Close to Haverfordwest? We work across the area, including:
Other extensions in Haverfordwest
- Rear
- Side
- Wraparound
- Part two-storey
- Over a garage
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Haverfordwest · First-floor extensions across Dyfed
The quickest next step is a visit. We'll look at your house in Haverfordwest and give you an honest view of the options.