Extensions over a garage in Baldock

The basics for Baldock at a glance.

Postcode districts: SG7
County / area: Hertfordshire, England
Price region: East of England
Guide price: £32,500–£47,500 (£1,800–£2,630 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Letchworth Garden City (1.7 miles), Hitchin (4.9 miles), Henlow (5.1 miles)
Distance to Watford: about 24.6 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 district SG7 in and around Baldock, along with neighbouring Letchworth Garden City, Hitchin and Henlow.

What it costs in Baldock

Guide prices for extensions over a garage in the East of England are around £1,800–£2,630 per m² of new floor space, including VAT. For a typical project with 3 m × 6 m of new first-floor space (18 m²), that's roughly £32,500–£47,500. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

Spec	Per m²	3 m × 6 m of new first-floor space (18 m²)
Essential	£1,660–£2,420 per m²	£30,000–£43,500
Standard	£1,800–£2,630 per m²	£32,500–£47,500
Premium	£2,160–£3,150 per m²	£39,000–£56,500

Planning and building regulations in Baldock

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 Baldock homes

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.

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

Look at the house
We start in Baldock with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about extensions over a garage in Baldock

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.

Who handles building regulations for a project in Baldock?

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 Baldock?

We cover Baldock (SG7) and nearby places including Letchworth Garden City, Hitchin and Henlow, plus the rest of Hertfordshire. 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.

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

Other towns near Baldock:

Other extensions in Baldock

All two-storey extension services in Baldock · Extensions over a garage across Hertfordshire

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.