Llanelli · Dyfed

Extensions over a garage in Llanelli

For an extension over a garage in Llanelli, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Dyfed.

Quick reference for homeowners in Llanelli.

Postcode districts
SA15
County / area
Dyfed, Wales
Price region
Wales
Guide price
£29,000–£42,000 (£1,610–£2,350 per m²)
Approval route
Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission.
Nearest towns
Burry Port (3.6 miles), Gorseinon (5.2 miles), Pontarddulais (5.7 miles)
First visit
Free, no obligation

About an extension over a garage

An extension over a garage is a new first-floor room built on top of an existing attached garage, usually a bedroom, en-suite or study. It uses a footprint you already have, so it adds floor space without taking any garden. The garage walls and foundations often need strengthening or replacing to carry the new floor.

We cover postcode district SA15 in and around Llanelli, along with neighbouring Burry Port, Gorseinon and Pontarddulais.

What it costs in Llanelli

For budgeting in Llanelli, allow around £29,000–£42,000 for an extension over a garage with 3 m × 6 m of new first-floor space (18 m²). That's based on £1,610–£2,350 per m² including VAT for Wales. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

SpecPer m²3 m × 6 m of new first-floor space (18 m²)
Essential£1,480–£2,160 per m²£26,500–£39,000
Standard£1,610–£2,350 per m²£29,000–£42,000
Premium£1,930–£2,820 per m²£35,000–£50,500

Planning and building regulations in Llanelli

In Wales, building over a side garage can be permitted development if the result is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front of the house and does not widen the house by more than 50%. Garages close to the boundary usually fail these tests, so a householder application costing £585 is often needed.

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 Llanelli homes

Floor levels and headroom

Garage floors are often lower than the house, and the new first floor may not line up with the existing landing. We set the floor level to avoid awkward steps upstairs, while keeping enough headroom in the garage below for a car or storage.

Checking the garage foundations

Garages are often built on shallow strip footings sized for a single-storey wall and a light roof. A trial hole shows their depth and condition, and the engineer decides whether they can carry two storeys or need underpinning or new foundations inside the garage.

How we'd run your project

  1. Start at your house

    We come to your home in Llanelli, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Llanelli.

  3. Price it properly

    Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.

  4. Build and sign-off

    Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about extensions over a garage in Llanelli

Do I need planning permission for an extension over a garage in Llanelli?

Llanelli is in Wales, so Wales planning rules apply. Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does an extension over a garage cost in Llanelli?

Our guide for Wales, which covers Llanelli, is £1,610–£2,350 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £29,000–£42,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

How long does an extension over a garage take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Can I add an en-suite above the garage?

Yes, and it is a common choice for a main bedroom. The en-suite needs an extract fan under Part F, a route for the soil pipe down to the drains and enough fall for the waste, which can be harder over a garage. We plan the pipe route through the garage or an outside wall early.

Can my garage take a room on top?

Sometimes, but it needs checking. Many garages are built on shallow footings with thin walls, designed only for a single storey. We dig a trial hole and inspect the walls, and the structural engineer decides whether to reuse them, strengthen them, underpin the footings or build new foundations inside the garage.

Nearby

Nearby towns we cover for extensions over a garage:

Other extensions in Llanelli

All two-storey extension services in Llanelli · Extensions over a garage across Dyfed

Tell us about your house in Llanelli and we'll call you back to arrange a free, no-obligation visit.

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