Flint · Clwyd

First-floor extensions in Flint

If you live in Flint and need more room without moving, a first-floor extension is worth a serious look. We handle the drawings, approvals, structure and build.

What we'd confirm first for a project in Flint.

Postcode districts
CH6
County / area
Clwyd, 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
Holywell (Clwyd) (4.5 miles), Deeside (4.9 miles), Mold (5.4 miles)
Distance to Wrexham
about 14.9 miles
First visit
Free, no obligation

About a first-floor extension

A first-floor extension is a new upstairs room built on top of an existing single-storey part of your house, such as a rear kitchen extension, a utility or a side annexe. It adds a bedroom, bathroom or study without enlarging the footprint. Whether it works depends mainly on whether the walls and foundations below can carry the extra load.

We cover postcode district CH6 in and around Flint, along with neighbouring Holywell (Clwyd), Deeside and Mold.

What it costs in Flint

Our guide for Wales is £1,660–£2,390 per m² including VAT. On a project with 4 m × 3.5 m of new first-floor space (14 m²), that puts a first-floor extension in Flint at roughly £23,000–£33,500. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

SpecPer m²4 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 Flint

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 Flint 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.

Tying into the house

The new floor and walls must line up with the existing first floor, often through a new opening in the rear wall above the old one. Floor levels, the position of upstairs windows and the existing roof all affect where the opening can go, so we survey both floors carefully.

How we'd run your project

  1. Look at the house

    We start in Flint with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. 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 Flint

How much does a first-floor extension cost in Flint?

Our guide for Wales, which covers Flint, 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.

Which postcodes do you cover around Flint?

We cover Flint (CH6) and nearby places including Holywell (Clwyd), Deeside and Mold, plus the rest of Clwyd. The first site visit is free.

Who handles building regulations for a project in Flint?

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.

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

Other towns near Flint:

Other extensions in Flint

All two-storey extension services in Flint · First-floor extensions across Clwyd

The quickest next step is a visit. We'll look at your house in Flint and give you an honest view of the options.

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