Extensions over a garage in Horsforth

The basics for Horsforth at a glance.

Postcode districts: LS5, LS16 and LS18
County / area: West Yorkshire, England
Price region: Yorkshire and the Humber
Guide price: £29,000–£42,000 (£1,610–£2,350 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Yeadon (2.5 miles), Pudsey (3.4 miles), Guiseley (3.8 miles)
Distance to Leeds: about 4.9 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 districts LS5, LS16 and LS18 in and around Horsforth, along with neighbouring Yeadon, Pudsey and Guiseley.

What it costs in Horsforth

Using our Yorkshire and the Humber rates, an extension over a garage with 3 m × 6 m of new first-floor space (18 m²) comes to about £29,000–£42,000, including VAT. Bigger or more glazed designs cost more per m². Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	3 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 Horsforth

In England, most garages sit beside the house, so building over one makes a two-storey extension beyond a side wall, which always needs planning permission. If the garage is at the rear, the 3 m and 7 m rules for two-storey rear extensions apply, measured from the original house. A householder application costs £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Horsforth homes

Garage walls and the door opening

Garage walls are often a single skin of brick or block with piers, and the wide door opening needs a beam over it. Many over-garage extensions need new inner walls or a steel frame to carry the floor and to insulate properly, which we confirm before the design is fixed.

Matching the house

A room over a garage usually sits beside the front of the house in full view, so roof form, ridge height, windows and brick matter. Setting the front wall and ridge back slightly from the main house usually helps it look as if it belongs.

How we'd run your project

Understand the brief
At your home in Horsforth 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 England 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.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about extensions over a garage in Horsforth

Who handles building regulations for a project in Horsforth?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. 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 Horsforth?

We cover Horsforth (LS5, LS16 and LS18) and nearby places including Yeadon, Pudsey and Guiseley, plus the rest of West Yorkshire. The first site visit is free.

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

Horsforth is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How do I get into a room over the garage?

Usually through a new opening off the existing landing or a bedroom, so the stairs stay where they are. If the floor levels do not match, a step or two may be needed inside the new room. Where a landing opening is not practical, a new stair from a converted garage is an option.

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.

Nearby

We also cover places near Horsforth, including:

Other extensions in Horsforth

All two-storey extension services in Horsforth · Extensions over a garage across West Yorkshire

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