Extensions over a garage in Alnwick

Quick reference for homeowners in Alnwick.

Postcode districts: NE66 and NE67
County / area: Northumberland, England
Price region: North East England
Guide price: £28,500–£41,500 (£1,580–£2,300 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Amble (7.3 miles), Hadston (9.1 miles), Pegswood (16.3 miles)
Distance to Blyth: about 21.2 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.

Around Alnwick we also work in Amble, Hadston and Pegswood, and across the rest of Northumberland. Postcode districts in and near Alnwick: NE66 and NE67.

What it costs in Alnwick

A guide price for Alnwick: around £28,500–£41,500 for 3 m × 6 m of new first-floor space (18 m²). That works out at £1,580–£2,300 per m² of new floor space, including VAT at 20%. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

Spec	Per m²	3 m × 6 m of new first-floor space (18 m²)
Essential	£1,450–£2,110 per m²	£26,000–£38,000
Standard	£1,580–£2,300 per m²	£28,500–£41,500
Premium	£1,890–£2,750 per m²	£34,000–£49,500

Planning and building regulations in Alnwick

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 Alnwick 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.

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.

How we'd run your project

Understand the brief
At your home in Alnwick we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
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 Alnwick

Which postcodes do you cover around Alnwick?

We cover Alnwick (NE66 and NE67) and nearby places including Amble, Hadston and Pegswood, plus the rest of Northumberland. The first site visit is free.

Who handles building regulations for a project in Alnwick?

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.

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

Our guide for North East England, which covers Alnwick, is £1,580–£2,300 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £28,500–£41,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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

Close to Alnwick? We work across the area, including:

Other extensions in Alnwick

All two-storey extension services in Alnwick · Extensions over a garage across Northumberland

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