Gillingham · Kent

Extensions over a garage in Gillingham

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

Quick reference for homeowners in Gillingham.

Postcode districts
ME3, ME7 and ME8
County / area
Kent, England
Price region
South East England
Guide price
£34,500–£50,500 (£1,930–£2,800 per m²)
Approval route
Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns
Chatham (1.1 miles), Rochester (1.9 miles), Strood (3.1 miles)
Distance to Maidstone
about 8.6 miles
First visit
Free, no obligation

About an extension over a garage

An extension over a garage suits you if you have an attached single garage beside the house and need an extra bedroom or a larger main bedroom with an en-suite. You get an inspection of the garage structure, a design that matches the house, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.

Gillingham sits about 8.6 miles from Maidstone. Closer to home, Chatham is 1.1 miles away and Rochester 1.9 miles.

What it costs in Gillingham

For budgeting in Gillingham, allow around £34,500–£50,500 for an extension over a garage with 3 m × 6 m of new first-floor space (18 m²). That's based on £1,930–£2,800 per m² including VAT for South East England. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

SpecPer m²3 m × 6 m of new first-floor space (18 m²)
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

Planning and building regulations in Gillingham

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 Gillingham homes

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.

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

  1. Visit and first ideas

    One of our team visits your house in Gillingham, checks the walls, roof and drains, and sketches out options with you.

  2. Choose the approval route

    Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. On site

    One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about extensions over a garage in Gillingham

How long does an extension over a garage take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), 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.

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

Our guide for South East England, which covers Gillingham, is £1,930–£2,800 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £34,500–£50,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Which postcodes do you cover around Gillingham?

We cover Gillingham (ME3, ME7 and ME8) and nearby places including Chatham, Rochester and Strood, plus the rest of Kent. The first site visit is free.

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.

Do I need to convert the garage as well?

No. You can keep the garage for parking or storage and build only the room above, as long as the floor between them and any door into the house meet fire separation rules. Converting the garage at the same time is often good value, because the walls and foundations may be upgraded anyway.

Nearby

Other towns near Gillingham:

Other extensions in Gillingham

All two-storey extension services in Gillingham · Extensions over a garage across Kent

The quickest next step is a visit. We'll look at your house in Gillingham and give you an honest view of the options.

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