How Much Does a Home Extension Cost in Winchester? | 2026 Local Pricing Guide
With property prices remaining strong and limited opportunities to move within desirable neighbourhoods, many homeowners in Winchester are choosing to extend rather than relocate. A home extension can provide valuable extra space, improve layout and significantly increase property value — but understanding the likely costs is essential before you begin.
This guide explains how much a home extension costs in Winchester, what affects pricing, the different extension types available, and how to budget realistically in 2025.
Average Home Extension Costs in Winchester
Extension costs vary depending on size, complexity and finish. As a general guide, typical home extension costs in Winchester include:
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- Single-storey extension: £1,900 – £2,600 per m²
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- Double-storey extension: £2,100 – £2,900 per m²
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- Rear extension: £35,000 – £65,000+
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- Side extension: £40,000 – £75,000+
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- Wrap-around extension: £60,000 – £110,000+
These figures provide a useful starting point, but final costs will depend on your property, design choices and specification level.
What Affects the Cost of a Home Extension in Winchester?
1. Size and Layout
Larger extensions cost more overall, but layout also plays a key role. Simple, open-plan designs are generally more cost-effective than layouts with multiple rooms, bathrooms or complex structural changes.
2. Type of Extension
Different extension styles come with different cost implications:
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- Single-storey extensions – Lower overall cost and quicker build time
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- Double-storey extensions – Higher upfront cost but better value per square metre
- Wrap-around extensions – Maximum space and transformation, but higher complexity and cost
3. Ground Conditions and Foundations
Groundworks can significantly impact costs, especially if:
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- Deeper foundations are required
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- Drainage needs relocating
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- Ground conditions are poor
A site survey helps identify these issues early and avoid surprises.
4. Structural Alterations
Most extensions involve some structural work, such as:
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- Removing load-bearing walls
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- Installing steel beams (RSJs)
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- Altering roof structures
These works add complexity but are often essential for modern, open-plan living spaces.
5. Specification and Finishes
Internal finishes can greatly affect the final price, including:
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- Flooring and tiling
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- Kitchen units and appliances
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- Bathroom fittings
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- Windows, doors and glazing
Choosing mid-range finishes is a common way to balance quality and budget.
Do You Need Planning Permission for an Extension in Winchester?
Many home extensions fall under Permitted Development, meaning planning permission may not be required if size and design limits are met.
Planning permission is more likely to be required for:
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- Double-storey extensions
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- Extensions close to boundaries
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- Side or front extensions
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- Properties in conservation areas
Winchester has several conservation areas, so it’s particularly important to check local planning constraints early.
Regardless of planning permission, Building Regulations approval is always required.
Single-Storey vs Double-Storey Extensions: Cost Comparison
Single-Storey Extensions
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- Lower overall build cost
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- Shorter construction time
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- Ideal for kitchens, dining areas and family rooms
Best suited to homeowners improving layout rather than adding bedrooms.
Double-Storey Extensions
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- Higher initial cost
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- Better value per square metre
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- Adds bedrooms and bathrooms
Often the better long-term solution for growing families.
How Long Does a Home Extension Take?
Typical build times include:
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- Single-storey extension: 8–12 weeks
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- Double-storey extension: 12–20 weeks
Timescales depend on complexity, weather and material availability.
How Much Value Can an Extension Add in Winchester?
A well-designed extension can add 15–25% to a property’s value, particularly when it:
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- Improves layout and flow
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- Adds bedrooms or bathrooms
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- Creates open-plan living space
In Winchester’s strong property market, extensions are often viewed as a solid long-term investment.
Budgeting Tips for Your Extension Project
To keep your project on track:
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- Define your requirements clearly from the outset
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- Allow a 10–15% contingency for unexpected costs
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- Prioritise structure and layout over high-end finishes
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- Request detailed, itemised quotes
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- Work with an experienced local builder
Good planning reduces the risk of delays and cost overruns.
Why Use a Local Winchester Builder for Your Extension?
A local builder offers:
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- Knowledge of Winchester housing styles
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- Familiarity with local planning expectations
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- Reliable project management
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- Access to trusted local suppliers and trades
Local experience helps ensure your extension is delivered efficiently, safely and to a high standard.
Final Thoughts
Understanding home extension costs in Winchester is a crucial first step before starting any building project. While prices vary depending on size and specification, careful planning and professional advice can help you achieve excellent results within your budget.
Whether you’re extending to create more living space, improve functionality or add long-term value, a well-planned home extension with a local builder remains one of the most effective property improvements in 2025.