Garage conversions with a room above in Kent

Kent at a glance

Nation: England
Price region: South East England
Postcode areas: BR, CT, DA, ME, TN
Towns covered: 31 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.

Across Kent we cover Maidstone (ME14), Gillingham (ME3), Chatham (ME4), Tunbridge Wells (TN1), Folkestone (CT18) and Margate (CT9), plus the smaller places around them.

Guide price in South East England

In South East England, which includes Kent, we'd expect a garage conversion with a room above to cost around £34,500–£50,500 (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), or £1,930–£2,800 per m² including VAT. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

Spec	Per m²	Typical project
Essential	£1,770–£2,580 per m²	£32,000–£46,500
Standard	£1,930–£2,800 per m²	£34,500–£50,500
Premium	£2,310–£3,370 per m²	£41,500–£60,500

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

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.

Infilling the garage door

The garage door opening is usually filled with a new wall and a window, on a new foundation, with brick to match. The new front wall needs a cavity, insulation and a damp-proof course, and the window position should line up with the room above.

How we work in Kent

Visit and first ideas
One of our team visits your house in Kent, checks the walls, roof and drains, and sketches out options with you.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Kent.
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 Kent

Garage conversions with a room above in Kent: questions

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

In South East England our guide is £1,930–£2,800 per m² including VAT, so about £34,500–£50,500 (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.

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.

Is it worth converting the garage at the same time as building above it?

Usually, yes. Building a room above often means upgrading the garage foundations and walls anyway, so converting it at the same time spreads that cost over two rooms. You also have one period of disruption, one set of drawings and one building regulations approval instead of two.

Will I need planning permission in Kent?

Kent 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 Kent · About garage conversions with a room above