How Much Does a House Extension Cost in Norfolk? A Complete 2025 Guide
A house extension is one of the most effective ways to add space, value, and comfort to your home — without the cost and stress of moving. Whether you’re considering a rear extension, side extension, wraparound build, or even a two-storey addition, understanding the costs involved is essential for planning a successful project.
This guide breaks down the typical cost of house extensions in Norfolk in 2025, what affects those costs, and how to budget realistically.
Average Extension Costs in Norfolk (2025)
While prices vary depending on size, design, materials, and specification, the average extension prices in Norfolk are:
Single-Storey Extension
Basic finish: £1,500 – £1,900 per m²
Mid-range finish: £1,900 – £2,400 per m²
High-end finish: £2,400 – £3,200+ per m²
Two-Storey Extension
Typically 50–70% more than single-storey, but more cost-effective per m².
Rear Extensions
Usually the most straightforward and cost-efficient.
Side Extensions
Can require more structural work depending on access and layout.
Wraparound Extensions
Generally the highest cost due to combined structural complexity.
What Affects the Cost of Your Extension?
1. Size & Floor Area
The biggest cost factor is simply how much space you're adding.
More space = more materials, more labour, and higher overall cost.
2. Type of Extension
Different builds require different levels of structural work:
Rear extensions are often simplest
Side extensions may require access solutions
Wraparound extensions involve multiple structural walls
Two-storey extensions need deeper foundations and reinforcement
3. Ground Conditions
Before building begins, contractors assess:
Soil stability
Drainage systems
Access for machinery
Tree roots
Existing foundations
Difficult ground conditions increase costs.
4. Structural Engineering
Any extension that removes or alters load-bearing walls requires:
Structural calculations
Steel beams (RSJs)
Additional support
This is essential for safety and adds to the project budget.
5. Materials & Finishes
Your choice of:
Brickwork
Windows & doors
Roof style
Flooring
Kitchens & bathrooms
Insulation
Electrical & plumbing
—all heavily influence cost.
6. Utility Connections
Extensions that include:
Bathrooms
Kitchens
Heating upgrades
Electrical setups
will cost more depending on the level of work required.
7. Planning Permission & Regulations
You may need:
Planning permission
Structural drawings
Building control inspections
Most extensions also require compliance with regulations covering:
Energy efficiency
Drainage
Fire safety
Structural integrity
How to Budget Effectively
✔ Add a contingency of 10–15%
Unexpected issues can arise once work begins.
✔ Get a detailed quote
A breakdown helps you understand exactly what you're paying for.
✔ Choose a reputable Norfolk contractor
The cheapest quote usually means lower quality or hidden costs.
The best value comes from skilled contractors who deliver long-lasting results.
Do House Extensions Add Value?
Absolutely — especially when built by experienced professionals.
A well-designed, well-constructed extension can increase your property’s value by:
10% – 25% or more depending on size and design.
Kitchens and open-plan family spaces consistently deliver the highest return on investment.
Why Choose Reeve & Son Construction for Your Extension?
Based in Norfolk, we specialise in:
Rear, side, and wraparound extensions
Single- and two-storey extensions
Structural alterations & steel installation
Full project management
High-quality finishes
Transparent pricing
Reliable communication throughout
We handle every stage of your project — from groundwork to completion — ensuring a smooth, stress-free experience.
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Thinking about an extension in 2025?
Get in touch with Reeve & Son Construction today for a detailed quote and expert guidance.