Expert Extension Design — Fixed Fee, No Surprises
Qualified architectural technicians. Fixed-fee packages from £1,350 + VAT. Full planning drawings, building regulations, and structural calculations — all included.
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What We Do
The Complete Extension Design Package
Hampshire Build provides the complete architectural design service for residential extensions. We handle everything from initial concept through to planning approval and building regulations drawings — all on a fixed fee so you know exactly what you're paying before you commit.
We are qualified architectural technicians, not builders. Our focus is design, drawings, and planning — giving you the professional documentation you need to get planning permission and instruct a contractor with confidence.
Planning Drawings & Application
Site plan, floor plans, and elevations drawn to planning authority standards. We submit the full application on your behalf.
Building Regulations Drawings
Full technical drawing set with structural calculations from a qualified engineer. Everything your builder needs to comply with building regulations.
Contractor Tender Management
Premium Package clients receive a detailed schedule of works and tender documentation sent to two vetted contractors — with a proposal comparison so you can make an informed decision.
Transparent Pricing
Three Fixed-Fee Packages
All prices exclude VAT. No hidden costs — the fee you see is the fee you pay for the specified scope.
All packages include one on-site measured survey. Council fees and third-party costs are separate. See full terms.
Why Choose Us
The Hampshire Build Difference
We produce high-quality drawings that meet planning authority requirements first time.
Your package price is fixed. No hourly billing surprises — you know exactly what you'll pay.
Design only — no build markup. We have no commercial interest in who builds your extension.
Design reviews by phone or video call — flexible, efficient, and built into the fixed fee.
We commit to completing your measured survey within 10 working days of receiving your deposit.
Hampshire, Hertfordshire, Surrey, Berkshire, Buckinghamshire, Oxfordshire, West Sussex & Wiltshire.
How It Works
Four Simple Steps
Complimentary Consultation
Discuss your project, budget, and vision. We assess feasibility and advise on the right package — no commitment required.
Measured Survey
We visit your property within 10 working days of your deposit to take full measurements and a site report.
Design & Planning
Your drawings are produced and the planning application submitted to your local authority.
Building Regulations
Full technical drawing set and structural calculations delivered — everything your builder needs to start on site.
Client Reviews
What Our Clients Say
"Thank you Mark, we have really appreciated how prompt you have been with responding to emails and calls whilst we have been going through design and planning stages. Your reassurance, reliability and professionalism have been a great help."
Sandra Trott
"Excellent service from start to finish. Our original architect continually let us down, but Mark at Hampshire Build was responsive, professional and delivered exactly what we needed for our extension project."
Andrew Stone
"Mark & his team were brilliant in helping us finish off our build — they were kind, efficient and have done a great job. Will definitely be using them again in the future for any work!"
Charlie Brenninkmeijer
Where We Work
Service Areas
We cover eight counties across South and South-East England. Click your county for local information.
Common Questions
Extension Design — FAQ
How much does extension design cost in Hampshire?
Do I need an architect for a house extension?
How long does planning permission take in Hampshire?
What is included in a fixed-fee extension design package?
Do you need building regulations drawings for an extension?
Ready to Get Started?
Book a complimentary consultation and discuss your project with us. No commitment — we'll assess feasibility and confirm which package is right for you.
Or email us at info@hampshirebuild.co.uk