Rear Extension, Farnham, Surrey GU9

How much does a rear extension in Farnham, GU9 cost?
A single-storey rear extension in Farnham, GU9 like this one came in at around £67,000 including VAT, delivered in an eight-week build programme on a fixed-price contract with a staged payment plan. That covered the 16m² extension itself — foundations on ground screws, structural steel frame, insulated external walls, silicone render, flat roof, painted walls and ceilings, electrics, lighting and flooring — plus two 1m × 1m flat-roof skylights, a high-level clerestory window, a new rendered blockwork wall between the existing conservatory and the new extension, the careful re-use of the home's existing french doors in the new build, design fees for the planning application and building control drawings, and the variations agreed during the works. Every project is priced individually against survey and specification.

How long does a rear extension in Farnham take to build?
This 16m² Farnham, GU9 rear extension was delivered in an eight-week build programme on site. Because Vita Modular builds on ground screws and a structural steel frame rather than mass concrete foundations, the build gets out of the ground quickly, with fewer wet trades and less waiting — and the staged payment plan is tied to visible milestones like watertight completion, so progress is easy to track. Every programme is confirmed at contract stage with a committed start date.

Can you build an extension on ground screws instead of concrete foundations?
Yes. This Farnham extension was carried on ground screws supporting a structural steel frame, following a reduced-level dig across the footprint. Ground screws avoid mass concrete, dramatically reduce spoil and wet trades, and get the build out of the ground quickly — with a ground test completed as part of the design process to confirm they were suitable for the site, and a costed concrete fallback agreed in advance so there were no surprises either way.

Can existing french doors be re-used in a new extension?
Often, yes. On this Farnham, GU9 project the home's existing UPVC french doors were carefully removed and re-installed in the rear elevation of the new extension in place of a new door set — a more sustainable outcome, with one less door set going to waste.

Can you build an extension next to an existing conservatory?
Yes. On this project a new blockwork wall was formed between the existing conservatory and the new extension, giving the new build a proper masonry structure to build against while the conservatory stayed in place and in use. The wall was rendered on completion with an aluminium capping to match the extension, so the junction reads as one considered piece of design rather than an afterthought.

How do you bring natural light into a single-storey rear extension?
This Farnham extension used a three-part daylight strategy: two 1m × 1m skylights in the flat roof pulling light deep into the plan, a 1.2m × 0.4m high-level clerestory window along the neighbour's side — daylight without overlooking — and the re-used glazed french doors opening the rear elevation to the garden. High-level glazing is a particularly useful move on tight suburban plots where a full-height window would face directly into the property next door.

Do I need planning permission for a rear extension in Farnham?
It depends on the size and position of the extension — some single-storey rear extensions fall within permitted development rights, while others need a full planning application. On this Farnham, GU9 project, Vita Modular prepared the drawings for the planning application and produced the technical building control package as part of the project, with the design fee built into the account. Every property is different, so we confirm the planning position for your home at design stage.

What happens if extra works are needed during the build?
Extra works are priced, agreed with the client and issued as formal variations, so the account stays transparent from first quote to final account. On this Farnham project the variations included forming reveals and finishes to an existing window and works to the existing manhole carried out to the water authority's directions. This is exactly why Vita Modular works to a fixed-price contract with a transparent variations process rather than a handshake and a verbal price.

How is a Vita Modular extension paid for?
Through a staged payment plan tied to progress on site. On this Farnham project the stages were: the design fee at the start, a deposit, an instalment on main delivery and commencement of works, a payment at watertight completion — when the external walls and roof covering are finished — and a final payment on the completion certificate. Nothing is due in full up front, and each stage is linked to something you can see.

Who builds house extensions in Farnham and West Surrey?
Vita Modular is a design-and-build extension company working across Farnham, Wrecclesham, Hale, Heath End, Badshot Lea, Rowledge and the wider Waverley and West Surrey area — and nationwide. One team handles the whole project: survey, design, structural design, fixed-price contract, construction and completion, backed by a 10-year warranty. This GU9 case study — a 16m² rear extension with twin skylights, a clerestory window and re-used french doors, delivered in eight weeks — is a typical example of the work.