Single vs Double Storey Extensions in Northampton | Which Is Best?
If you’re considering extending your home in Northampton, one of the biggest decisions you’ll need to make is whether to build a single-storey or double-storey extension. Both options can transform how your home looks and functions, but the right choice depends on your budget, property type, space requirements and long-term plans.
This guide compares single-storey vs double-storey extensions in Northampton, helping homeowners understand the costs, benefits, planning considerations and which option works best for different types of properties.
Why Home Extensions Are Popular in Northampton
Northampton has a wide mix of Victorian terraces, 1930s semis and modern family homes. Many homeowners are choosing to extend rather than move because:
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- Property prices continue to rise
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- Stamp duty and moving costs are high
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- Extensions add space and long-term value
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- Families want to stay in established areas
Both single-storey and double-storey extensions are popular solutions, but they serve different needs.
What Is a Single-Storey Extension?
A single-storey extension adds space on the ground floor only. It’s commonly used to extend:
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- Kitchens
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- Dining rooms
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- Living areas
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- Utility rooms
Single-storey extensions are often built to the rear or side of a property and are ideal for improving layout and flow.
What Is a Double-Storey Extension?
A double-storey extension adds space across two floors, typically creating:
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- Additional bedrooms
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- Extra bathrooms or en-suites
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- Larger family layouts
Double-storey extensions are often used where homeowners need more overall space but want to maximise the return on their investment.
Cost Comparison: Single vs Double Storey Extensions
Single-Storey Extension Costs in Northampton
Typical costs include:
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- £1,800 – £2,500 per m²
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- £30,000 – £60,000+ depending on size and specification
Lower overall cost and shorter build time make single-storey extensions appealing for many homeowners.
Double-Storey Extension Costs in Northampton
Typical costs include:
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- £2,000 – £2,800 per m²
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- £50,000 – £90,000+ depending on size and complexity
Although more expensive upfront, double-storey extensions often provide better value per square metre.
Planning Permission Considerations
Single-Storey Extensions
Many single-storey extensions fall under Permitted Development, meaning planning permission may not be required if size and height limits are respected.
Planning permission may still be needed if:
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- The extension is close to boundaries
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- The property is in a conservation area
- Permitted Development rights have been removed
Double-Storey Extensions
Double-storey extensions almost always require planning permission due to:
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- Increased impact on neighbours
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- Height and massing concerns
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- Visual changes to the property
This can add time to the project but also allows for more flexible design.
Space & Layout: Which Adds More Practical Living Space?
Single-Storey Extensions
Best for:
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- Open-plan kitchen-living spaces
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- Improved flow and natural light
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- Garden access via bi-fold or sliding doors
They dramatically improve how the ground floor is used but don’t add bedrooms.
Double-Storey Extensions
Best for:
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- Growing families
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- Adding bedrooms and bathrooms
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- Long-term space needs
They offer a complete transformation of the home’s layout across two levels.
Impact on Garden Space
Single-storey extensions typically take up more garden space, which may be a concern for smaller plots. Double-storey extensions can provide more internal space with a smaller footprint, preserving outdoor areas.
Build Time & Disruption
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- Single-storey extensions: 8–12 weeks on average
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- Double-storey extensions: 12–20+ weeks depending on complexity
Both involve some disruption, but single-storey extensions are usually quicker and simpler to complete.
Which Adds More Value to a Northampton Property?
Both extension types can add significant value when designed well:
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- Single-storey extensions add value by improving layout and lifestyle appeal
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- Double-storey extensions often add more value by increasing bedroom count
In family-focused areas of Northampton, double-storey extensions can offer a stronger long-term return.
Which Option Is Right for Your Home?
A single-storey extension may be best if:
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- You want a modern kitchen or living space
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- Budget is a key consideration
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- You don’t need extra bedrooms
A double-storey extension may be better if:
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- You need more bedrooms or bathrooms
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- You’re planning to stay long-term
- You want maximum return on investment
Why Use a Local Northampton Builder?
A local builder understands:
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- Northampton housing styles
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- Local planning expectations
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- Structural challenges common in the area
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- How to design extensions that add real value
Local experience helps ensure your extension is delivered efficiently, safely and to a high standard.
Final Thoughts
When deciding between a single-storey or double-storey extension in Northampton, there’s no one-size-fits-all answer. The best option depends on your space needs, budget, property type and future plans.
With careful planning and professional advice, either extension type can transform your home, improve day-to-day living and add lasting value.