How Much Does an Extension Cost in Norfolk? A Complete 2025 Guide
Home extensions remain one of the most popular ways for Norfolk homeowners to add space and increase property value. Whether you need a larger kitchen, an extra bedroom, or a modern open-plan living space, an extension is often more affordable than moving — and fully customisable to your lifestyle.
This guide explains the real costs of building an extension in Norfolk in 2025, what affects the price, and how to budget effectively.
Average Cost of a House Extension in Norfolk (2025)
Typical price ranges:
Small extension (10–15m²): £25,000 – £45,000
Medium extension (20–30m²): £45,000 – £75,000
Large extension (30–50m²+): £75,000 – £150,000+
These prices depend on materials, design, structural requirements, and the specification of the kitchen, bathroom, or glazing.
Types of Extensions and Their Costs
1. Single-Storey Rear Extension
Ideal for open-plan kitchens, dining rooms, and larger living spaces.
Cost: £1,800 – £2,600 per m²
Most suitable for: Semi-detached, detached, and bungalow properties.
2. Side Return Extension
Perfect for terraced homes looking to widen narrow kitchen spaces.
Cost: £2,000 – £3,000 per m²
Benefits: Transforms unused passageways into prime living space.
3. Double-Storey Extension
Allows both downstairs and upstairs rooms to be expanded.
Cost: £2,500 – £3,500 per m²
Biggest advantage: Significantly increases home value.
4. Wrap-Around Extension
Combines a rear and side return extension to create a large, flexible space.
Cost: £60,000 – £150,000+
Great for: Major renovations and full ground-floor transformation.
Key Factors That Affect Cost
1. Size & Complexity
The larger the extension, the higher the cost — but cost per m² often decreases as size increases.
2. Foundations & Ground Conditions
Clay soil, sloping ground, or drainage work can increase costs.
3. Roof Type
Flat roofs are cheaper
Pitched roofs last longer and look more premium
4. Glazing & Doors
Bi-fold and sliding doors are popular but can raise the budget.
5. Kitchen or Bathroom Installation
These can account for 30–50% of your total spend due to plumbing, electrics, and fixtures.
6. Material Specifications
Premium finishes, custom joinery, and structural steelwork can all influence final pricing.
Planning Permission in Norfolk
You may not need planning permission if your extension falls under Permitted Development, but this depends on:
Size limitations
Placement on the plot
Roof height
Proximity to boundaries
You will always need building regulation approval.
A reputable contractor will guide you through planning, drawings, and approvals.
How Long Does It Take to Build an Extension?
Typical timeline:
Design & planning: 4–10 weeks
Building regulations: 2–6 weeks
Construction:
Small extension: 8–12 weeks
Medium: 12–16 weeks
Large: 16–28 weeks
Complex structural work or custom interiors may add extra time.
How to Save Money on Your Extension
Keep plumbing fixtures in their original locations
Choose cost-effective materials
Avoid unnecessary structural changes
Consider a simple roofline
Plan lighting and heating early
Working with an experienced builder helps avoid unexpected costs.
Why Extensions Are a Smart Investment
A well-built extension can add 15–25% to the value of your home.
Homeowners in Norfolk often extend to create:
Larger kitchens
Extra bedrooms
Home offices
Open-plan living spaces
Modern garden rooms
With demand for larger, flexible homes increasing, extensions remain one of the best long-term investments.
Final Thoughts
Every home is different — and so is every extension. Understanding the costs and planning carefully ensures your project runs smoothly and stays within budget.
If you're considering a home extension in Norfolk, a professional builder can guide you through every stage, from planning and design to completion.
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Reeve & Son Construction specialise in bespoke home extensions across Norfolk.
Get in touch for expert advice, planning support, and a free consultation.