How Much Does a House Extension Cost in Brighton? A Local Guide
If you’re considering a house extension in Brighton, one of the first questions you’re likely to ask is how much is it going to cost?
House extension costs can vary significantly depending on the size, type, and complexity of the build, as well as the property itself.
In this guide, we break down typical house extension costs in Brighton, explain what affects pricing, and help you understand what to budget for before starting your project.
Average House Extension Costs in Brighton
As a general guide, homeowners in Brighton can expect the following build-only costs:
- Single-storey extension: £1,800 – £2,500 per m²
- Two-storey extension: £2,000 – £2,800 per m²
- Wraparound or complex extensions: £2,500 – £3,200+ per m²
These figures cover construction work but do not usually include planning fees, design costs, or high-end finishes.
Brighton property prices mean many homeowners choose to extend rather than move, making extensions a popular long-term investment.
Cost of Different Types of Extensions
Single-Storey Rear Extensions
Single-storey extensions are the most common choice in Brighton, particularly for kitchen-diners and family living spaces.
Typical cost range:
- £35,000 – £65,000+, depending on size and finish
They are often more affordable than multi-storey builds and can dramatically improve layout and natural light.
Two-Storey Extensions
Two-storey extensions provide additional space upstairs and downstairs, making them ideal for growing families.
Typical cost range:
- £60,000 – £100,000+
While more expensive, the cost per square metre can be better value when creating multiple rooms.
Side Return & Wraparound Extensions
Side return and wraparound extensions are popular in Brighton’s period and terraced properties, where space is limited.
Typical cost range:
- £45,000 – £85,000+
These projects are more complex due to structural work and access considerations but can transform narrow or underused spaces.
What Affects the Cost of an Extension?
Several factors influence how much your extension will cost.
Size & Design
Larger extensions naturally cost more, but complex designs, large openings, and bespoke layouts also increase costs. Flat roofs, skylights, and bi-fold doors are popular but add to the budget.
Property Type & Age
Brighton has a high number of period and Victorian properties. Older homes often require additional structural work, upgraded foundations, or remedial works, which can increase costs.
Planning & Structural Requirements
If planning permission is required, there will be additional fees for applications, drawings, and possible structural calculations. Steel beams and groundworks can also significantly affect the final price.
Finishes & Specifications
Internal finishes make a big difference to cost. Kitchens, flooring, heating upgrades, and bespoke joinery can quickly increase the overall budget beyond basic build costs.
Planning Permission & Associated Costs
Some extensions fall under permitted development, while others require full planning permission. In Brighton, conservation areas and period properties may be subject to additional restrictions.
Typical additional costs may include:
- Architectural drawings
- Planning application fees
- Structural engineer calculations
- Building control fees
These costs are often overlooked early on but should be included in your overall budget planning.
Hidden Costs to Be Aware Of
When budgeting for an extension, homeowners should also consider:
- Electrical and plumbing upgrades
- Heating system capacity
- Drainage adjustments
- Temporary living arrangements if required
- Redecoration of existing areas
A contingency of 10–15% is recommended to cover unexpected costs.
Is a House Extension Worth the Cost?
In many cases, extending a property in Brighton adds significant value. A well-designed extension can increase both the usability and market appeal of a home, often outweighing the cost of the build itself.
Beyond financial value, extensions allow homeowners to stay in an area they love while adapting their home to suit changing needs.
How Long Does a House Extension Take?
Build times vary, but as a guide:
- Single-storey extensions: 10–14 weeks
- Two-storey extensions: 14–20 weeks
This does not include planning and design stages, which can add several months before construction begins.
Choosing the Right Builder in Brighton
Working with experienced local builders is key to keeping costs under control. Local knowledge helps with:
- Planning requirements
- Property styles
- Access challenges
- Realistic timelines and pricing
Clear communication, detailed quotes, and realistic expectations are essential for a successful extension project.
How to Get an Accurate Extension Quote
To receive an accurate quote, builders will usually need:
- Plans or drawings
- Property access
- Details of finishes and specifications
- Understanding of any structural requirements
The clearer the brief, the more accurate the pricing will be.
Final Thoughts on Extension Costs in Brighton
House extension costs in Brighton vary widely, but understanding typical price ranges and influencing factors makes planning far easier. Whether you’re adding a single-storey extension or undertaking a more complex build, careful budgeting and professional advice are essential.
An extension is a major investment, but when done properly, it can transform how you live in your home while adding long-term value.