Garage conversions with a room above in Northumberland

Northumberland at a glance

Nation: England
Price region: North East England
Postcode areas: NE, TD
Towns covered: 19 listed below, plus surrounding villages
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Site visits: Free, no obligation

What a garage conversion with a room above involves

A garage conversion with a room above is a project that turns an attached garage into living space and builds a new room on top, so you gain space on both floors in one build. It suits a single garage beside the house that is no longer used for a car. Doing both together means the walls, foundations and insulation are upgraded once.

Towns in Northumberland include Blyth (NE24), Cramlington (NE23), Ashington (NE63), Bedlington (NE22), Darras Hall (NE18) and Morpeth (NE61). If yours isn't listed, we still cover it.

Guide price in North East England

Using our North East England rates, a garage conversion with a room above with 3 m × 6 m of new first-floor space (18 m²) comes to about £28,500–£41,500 (for the room above; converting the garage itself is priced after the survey), including VAT. Bigger or more glazed designs cost more per m². The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

Spec	Per m²	Typical project
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

Rules in England

In England, converting a garage on its own often needs no planning permission, but building a room above a side garage makes a two-storey extension beyond a side wall, which needs planning permission costing £548 (or £575 for applications made from 8 December 2026). Some estates have conditions removing garage conversion rights, which we check first.

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.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Stairs and access

The room above is usually reached from the existing landing, while the converted garage opens off the hall. If the levels do not work, a new stair inside the converted garage can serve the room above, which we test in the layout.

Raising and insulating the floor

Garage floors are usually lower than the house and have no insulation or damp-proof membrane. We raise the floor to meet the house level where possible, with insulation and a membrane, so the converted room is warm and dry and does not have a step down.

How we work in Northumberland

Look at the house
We start in Northumberland with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
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.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Towns we cover in Northumberland

Garage conversions with a room above in Northumberland: questions

How much does a garage conversion with a room above cost in Northumberland?

In North East England our guide is £1,580–£2,300 per m² including VAT, so about £28,500–£41,500 (for the room above; converting the garage itself is priced after the survey) for 3 m × 6 m of new first-floor space (18 m²). Essential and Premium specs move that by roughly 8% down or 20% up.

Do I need planning permission to convert my garage?

In England, converting an attached garage to a room often needs no planning permission when the work is internal, unless a condition or Article 4 direction removes that right. Building regulations approval is always needed. The room above usually needs planning permission when the garage is at the side.

Does the room above need a fire door if the garage is converted?

Once the garage becomes a habitable room, the fire separation needed between a garage and the house usually falls away. The new bedroom above still needs an escape window or a protected route to the stairs, and smoke alarms. If you keep part of the garage for storage, separation may still be needed, which we confirm with building control.

How warm will a converted garage be?

As warm as the rest of the house, if it is built properly. In England the new walls, floor and roof must meet limiting U-values of 0.18 W/m²K for walls and floors and 0.15 for roofs, and new windows 1.4. We add insulation and a damp-proof membrane, and extend the heating.

Will I need planning permission in Northumberland?

Northumberland is in England. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.

Neighbouring areas

All extension services in Northumberland · About garage conversions with a room above