Extensions over a garage across Billericay
We design and build over-garage extensions for houses in Billericay, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in BillericayFrom £25,000 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsCM11, CM12
What we take care of
- Insulation, electrics, heating and finish
- Design and householder planning application
- Opening into the existing first floor
- Structural survey of garage walls and foundations
Covering Billericay
Our survey diary covers Billericay, including CM11, CM12. The same team covers Basildon (4 miles), Wickford (5 miles), Brentwood (5 miles), Stanford-le-Hope (7 miles), all within easy reach.
Just over the Greater London border, Hornchurch is about 10 miles away. The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
Will the council need to approve it?
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Guide prices for Billericay
Prices below are for Billericay, using the East of England factor of ×1.06. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Billericay: £1,910 to £3,600 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £25,000 – £31,500 | £26,500 – £34,500 | £34,000 – £43,500 |
| Over a large single garage 16 m² | £30,500 – £37,500 | £35,500 – £46,000 | £45,500 – £58,000 |
| Over a double garage 24 m² | £45,500 – £56,000 | £53,000 – £69,000 | £68,500 – £86,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Billericay home, measure up, talk through what you want and check the planning position.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Billericay
Do you cover all of Billericay?
Yes. We cover Billericay and the surrounding parts of Essex. Site visits are free and there is no obligation.
Do I need building regulations approval in Billericay?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Billericay, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How much does a room over a garage cost?
Our guide range is about £1,910 to £3,600 per m² including VAT. A single-garage room of about 12 m² usually costs £26,500 to £34,500 at standard spec, more if the garage needs rebuilding.
Can my garage take the weight of a room on top?
Some can and some cannot. Many garages have a single-skin wall or shallow foundations. Our structural engineer checks this before we give a fixed price.
Book a free site visit in Billericay
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
Tell us a little about the project and we will arrange a time.