Understanding Build Costs: Where Your Money Really Goes

Planning a home extension, renovation or new build is exciting — but understanding how your budget is spent is just as important as the design itself.

At Home Architecture, we often help clients make sense of build costs so they can plan realistically and get the most value from their investment.

1. The Real Cost of Building a Home

Every project is unique, but as a guide, typical build costs in Berkshire and the surrounding counties range from:

• £3000 per m² for a good-quality house extension + any remodelling cost
• £3,000 per m² for new builds with high-quality finishes

These figures vary depending on design complexity, materials, access, specification, and site conditions and the type of rooms your are creating, for example kitchens and bathrooms are more expensive to fit out then living areas or bedrooms. Please don't rely on these simple rules of thumb but they can provide a useful starting point when setting your budget and until we can analyse your project in more depth.

2. Where the Money Goes

Your build cost is made up of several key elements. Understanding these helps you prioritise and control spending:

a. Foundations and Groundworks

These are the hidden essentials. Excavation, drainage, and concrete foundations typically account for 10–15% of the total cost.

b. Structure and Shell

Walls, floors, and roof construction can make up 25–30% of the budget. The type of construction — timber frame, brick, block or steel — will influence the cost and build time.

c. Windows, Doors & External Finishes

Glazing and cladding choices have a big impact on both appearance and performance. High-quality windows may increase upfront cost but reduce energy bills long-term.

d. Internal Finishes

Plastering, flooring, kitchen and bathroom fittings, joinery, and decorations usually account for 30–40% of total costs — where much of your personality shows through the design.

e. Services & Energy Systems

Heating, plumbing, electrics, lighting, and renewables (like heat pumps or solar panels) typically use 10–15% of the budget, depending on efficiency goals.

f. Professional Fees & VAT

Architectural design, planning, structural engineering, and other consultants normally add 10–15% to the build cost, while VAT (if applicable) can be significant on renovation projects.

3. Planning for Contingency

Even with careful planning, unforeseen issues such as ground conditions or material price changes can arise. We recommend setting aside a 10–15% contingency in every budget — this keeps your project on track without stress.

4. How Home Architecture Helps You Stay on Budget

At Home Architecture, we guide clients through each stage — from concept design and planning to detailed drawings and project management. Using 3D visualisation and accurate cost modelling, we help you understand where your money goes before you start building, avoiding costly surprises later.

Our goal is to design spaces that look beautiful, perform efficiently, and fit your budget — so you can enjoy the journey as much as the result.

Ready to Start Planning Your Project?

If you’re considering an extension, remodel or new build in Newbury, Berkshire, Hampshire, Wiltshire or South Oxfordshire, get in touch with Home Architecture.

We’ll help you design with confidence and make sure every pound is well spent.

📞 01635 820814

📧 info@home-architecture.co.uk

🌐 www.home-architecture.co.uk