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Extensions over a garage in Liverpool: design, approvals and build

We design and build over-garage extensions for houses in Liverpool, with a written price once the survey and design are done and one point of contact throughout.

  • Guide price in LiverpoolFrom £22,500 inc VAT
  • PlanningHouseholder application needed
  • Build time12–18 weeks on site
  • Postcode districtsL1, L2, L3, L5, L69
Detached house with a bedroom extension above the attached garage

Planning and approvals in Liverpool

In England any side extension over one storey, including a room built over a side garage, needs a householder planning application. The fee is £548 from 1 April 2026 and councils aim to decide within 8 weeks.

The planning position for a specific Liverpool address depends on its history and any designations, which is why we check it at the first visit.

Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.

If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.

Applications are decided by the local planning authority (your district, borough or unitary council).

What we take care of

  • New floor structure, walls and roof
  • Structural survey of garage walls and foundations
  • Opening into the existing first floor
  • Insulation, electrics, heating and finish

How much does an over-garage extension cost in Liverpool?

For Liverpool we adjust our national guide rates by ×0.95, the factor we use for North West England. Figures include VAT; your written quote after the survey replaces them.

Typical rates in Liverpool: £1,710 to £3,230 per m² including VAT, depending on specification.

SizeEssentialStandardPremium
Over a single garage
12 m²
£22,500 – £28,000£23,500 – £31,000£30,500 – £39,000
Over a large single garage
16 m²
£27,000 – £33,500£31,500 – £41,500£41,000 – £52,000
Over a double garage
24 m²
£41,000 – £50,500£47,500 – £62,000£61,500 – £78,000

Try the guide-price tool to see a range for your own size and finish.

Covering Liverpool

Postcode districts we cover around Liverpool include L1, L2, L3, L5, L69, L70. Neighbouring towns we cover include Birkenhead (2 miles), Wallasey (4 miles), Litherland (4 miles), Bootle (4 miles).

For homes towards Cheshire, Ellesmere Port is around 10 miles away. The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.

How the project works

Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.

  1. Free site visit

    First, a site visit: we look at the house, garden, access and drains and listen to what you need.

  2. Design and approvals

    Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.

  3. Fixed written price

    We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.

  4. Build and sign-off

    The build is managed from start to finish, inspected at each stage and signed off on completion.

Your questions about an over-garage extension in Liverpool

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Liverpool, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.

Do I need building regulations approval in Liverpool?

Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.

How long does an over-garage extension take to build in Liverpool?

On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.

Does building over a garage need planning permission?

In England and the rest of the UK, adding a storey over a side garage almost always needs a planning application, because two-storey side extensions are outside permitted development.

How much does a room over a garage cost?

Our guide range is about £1,710 to £3,230 per m² including VAT. A single-garage room of about 12 m² usually costs £23,500 to £31,000 at standard spec, more if the garage needs rebuilding.

Book a free site visit in Liverpool

We will measure up, check the planning position and give you honest guide figures.

  • Free, no-obligation site visit
  • Planning route checked before you spend on drawings
  • Written price once the design is agreed
  • Building control sign-off at the end

Prefer to talk? Call 0800 088 6341 or .

Book a free site visit

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