House Extension Builders in Surrey & Hampshire
BFR Construction designs and builds house extensions across Surrey and Hampshire, from our base in the Farnborough and Camberley area. We manage the whole project: design advice, planning permission, building regulations, construction and finishing. You get one fixed quote and one team from start to handover.
Types of Extension We Build
Single-Storey Extensions
Double-Storey Extensions
Kitchen Extensions
Wrap-Around Extensions
Garage Conversions
How We Price Your Extension
Every extension is priced individually, because no two houses or briefs are the same. Here's how you get your number:
What affects the cost of an extension: the size in square metres, the groundworks your plot needs, the amount of glazing, and the finish you choose. A garage conversion is the most affordable way to add a room because the structure already exists, and a double-storey extension can work out better value per square metre than a single storey because the roof and foundations are shared.
Our Extension Process
House Extension FAQs
Do I need planning permission for a house extension?
Many single-storey rear extensions fall under permitted development. The standard limit is 3m deep for a semi-detached or terraced house and 4m for a detached house, under 4m high. Larger single-storey extensions (up to 6m and 8m respectively) can often still avoid a full planning application through the neighbour consultation scheme, where the council notifies your neighbours and allows a short objection window. Double-storey extensions have their own tighter limits, and conservation areas have extra rules. We confirm exactly what applies to your house at the free site visit. (Rules correct as of July 2026.)
How long does a house extension take?
A single-storey extension takes around 10–14 weeks on site. A double-storey extension takes 12–16 weeks. Planning permission, where needed, adds around 8 weeks before the build starts.
Can I stay in my house during the build?
Yes, almost all our clients do. We keep the existing house weathertight and separate the work area from your living space. The disruptive stage is the final knock-through, which we schedule with you in advance.
Will an extension add value to my home?
A well-built extension usually adds more value than it costs in Surrey and Hampshire, where space commands a premium. We'll give you a realistic view for your street at the site visit rather than quote a generic percentage.
Let's Work Together
Contact our team today to discuss your requirements.
