House Extensions and New Builds in Thames Valley
Asuka247 builds extensions and new homes across the Thames Valley. You get single-storey rear, double-storey side, wrap-around, loft conversions, and full new builds. We coordinate design, structural work, and building control sign-off. 15+ years trading. Fully insured.
What you get
- •Single-storey rear extensions
- •Double-storey side and rear extensions
- •Wrap-around and corner extensions
- •Loft conversions (dormer, hip-to-gable, mansard)
- •Full new builds and self-build support
- •Architectural drawings and planning coordination
- •Structural, first fix, second fix, and finishing under one contract
- •Building control sign-off managed on your behalf
Planning and design coordination
Most extensions need planning permission or work under permitted development rights. Asuka247 coordinates with architects, structural engineers, and party wall surveyors. We supply drawings for planning submission and building regulations. You get a single point of contact across design and build.
Construction phase
Once approvals land, we run the site. You get a weekly update, a signed-off payment schedule, and a named site manager. Trades arrive in sequence. Groundworks, brick and block, carpentry first fix, mechanical and electrical first fix, plasterboard, plaster, second fix, decoration, snagging.
Building control and warranties
Every stage is inspected by building control. Foundations, superstructure, insulation, drainage, airtightness. Asuka247 books inspections and handles sign-off. You get a completion certificate and a structural warranty for new builds. Workmanship warranty covers our extension work.
Typical timelines and costs
A single-storey rear extension takes 10 to 14 weeks on site. A double-storey takes 14 to 20 weeks. A loft conversion takes 8 to 12 weeks. New builds vary by size. We quote fixed prices with an itemised breakdown. Extras are agreed in writing before work starts.
How it works
- 1
Initial consultation
We walk the site and understand your brief.
- 2
Drawings and planning
We coordinate architectural drawings and planning submission.
- 3
Quote and contract
You get a priced itemised quote, written contract, and payment schedule.
- 4
Build
We run phased site work with weekly updates.
- 5
Handover
You get building control sign-off, snagging, and warranties.
Coverage
We cover Slough, Maidenhead, Windsor, Reading, Bracknell, Wokingham, Ascot, Newbury, High Wycombe, Marlow, Beaconsfield, Amersham, Henley-on-Thames, Staines, Egham.
Frequently asked questions
Do I need planning permission for an extension?
Some extensions fall under permitted development and do not need planning permission. Others need a full application. Asuka247 checks your boundary, property type, and conservation status before quoting.
What is a party wall agreement?
A party wall agreement is a legal document between you and your neighbour when you excavate near or build onto a shared wall. The Party Wall Act 1996 sets out the process. We coordinate surveyors when the Act applies.
How long does a single-storey rear extension take?
Most single-storey rear extensions take 10 to 14 weeks on site once planning and building regulations are cleared. Complex groundworks or bespoke joinery can extend the programme.
How much does an extension cost per square metre in the Thames Valley?
Thames Valley single-storey extensions sit in the 2500 to 3500 GBP per square metre range for standard finishes. Double-storey is usually 2000 to 2800 per square metre. Loft conversions sit at 1800 to 2600. These ranges apply in April 2026 and move with material costs.
Do you provide architectural drawings?
Yes. Asuka247 works with trusted local architects and supplies a full drawings package for planning and building regulations as part of the contract.
Do you handle building control sign-off?
Yes. We book every inspection, attend each visit, and hand you a completion certificate at the end.
What guarantees do you provide on new build work?
New builds ship with a structural warranty through an approved warranty provider. Asuka247 also provides a workmanship warranty on our contract works.
Which Thames Valley areas do you build in?
Slough, Maidenhead, Windsor, Reading, Bracknell, Wokingham, Ascot, Newbury, High Wycombe, Marlow, Beaconsfield, Amersham, Henley-on-Thames, Staines, and Egham.
Start your project
Call 07931 118 247, WhatsApp +44 7931 118 247, or book a 30-minute consultation online.
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Last updated: 2026-04-17