Dundry · Bristol

Extensions over a garage in Dundry

Our extensions over a garage service in Dundry covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.

The basics for Dundry at a glance.

Postcode districts
BS13
County / area
Bristol, England
Price region
South West 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
Bishopsworth (1.4 miles), Chew Magna (2.6 miles), Whitchurch (Bristol) (3.4 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.

We cover postcode district BS13 in and around Dundry, along with neighbouring Bishopsworth, Chew Magna and Whitchurch (Bristol).

What it costs in Dundry

A guide price for Dundry: around £32,500–£47,500 for 3 m × 6 m of new first-floor space (18 m²). That works out at £1,800–£2,630 per m² of new floor space, including VAT at 20%. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

SpecPer m²3 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 Dundry

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 Dundry 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.

Fire separation

If the garage stays a garage, the floor between it and the room above, and any door into the house, must give fire separation under building regulations. That usually means fire-resisting plasterboard ceilings, sealed gaps and a fire door, which we design in from the start.

How we'd run your project

  1. Free site visit

    We visit your home in Dundry, look at the structure, access and boundaries, and talk through what you want the new rooms to do.

  2. 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.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. Build it

    The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about extensions over a garage in Dundry

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

Our guide for South West England, which covers Dundry, is £1,800–£2,630 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £32,500–£47,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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.

Do I need planning permission for an extension over a garage in Dundry?

Dundry is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

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.

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

We also cover places near Dundry, including:

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All two-storey extension services in Dundry · Extensions over a garage across Bristol

Book a free site visit in Dundry and we'll tell you what's possible, what approvals you need and what the design stage would cost.

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