If you’re looking to add extra space to your home in the UK, building a house extension can be a smart investment. However, the costs can vary significantly depending on several factors, including the size, type of extension, materials, and location. This guide breaks down the average costs, so you can plan your project and budget effectively.
Key Factors Affecting the Cost of a House Extension in the UK
- Size of the Extension
- One of the main factors determining the cost is the size of the extension. A larger extension will naturally require more materials, labour, and time, pushing up the overall price.
- Type of Extension
- Single-storey extensions are typically cheaper than double-storey extensions. The average cost for a single-storey extension ranges between £1,200 and £2,500 per square metre.
- Double-storey extensions may cost slightly less per square metre but involve additional expenses for foundations and roofing, so the price typically ranges from £1,500 to £2,800 per square metre.
- Location
- The cost of building a house extension can vary significantly depending on where you live in the UK. London and the South East generally have the highest prices, while costs tend to be lower in the North and the Midlands.
- In London, you may pay anywhere from £2,000 to £3,500 per square metre due to higher labour costs and demand.
- Type of Materials
- The choice of materials can significantly affect your extension costs. For instance, using high-end materials like premium timber or imported stone will increase the price compared to standard brick or blockwork.
- Sustainable and eco-friendly materials may also have higher upfront costs but can save you money in the long run by reducing energy consumption.
- Labour Costs
- Labour costs can vary depending on your contractor’s experience, the complexity of the job, and your location. In some cases, you might also need to hire specialists such as architects or structural engineers, which adds to the overall cost.
Average House Extension Costs
Here’s a general breakdown of house extension costs in the UK:
- Small single-storey extension (15-20m²): £18,000 to £50,000
- Medium single-storey extension (20-30m²): £35,000 to £70,000
- Large single-storey extension (30-50m²): £50,000 to £100,000+
- Double-storey extension (30-40m²): £40,000 to £90,000
- Loft conversions or conservatories: £15,000 to £50,000
Additional Costs to Consider
- Planning Permissions and Building Regulations
- Depending on the size and type of your extension, you may need planning permission. The cost of applying for planning permission in the UK typically starts at £206. Building regulations approval is also necessary, and fees vary depending on your local authority.
- Architectural Fees
- Hiring an architect is often recommended for larger or more complex projects. Architectural fees generally range from 5% to 15% of the total project cost.
- Structural Engineer
- If your extension requires significant structural changes, such as removing a load-bearing wall, you may need to hire a structural engineer. The cost can range between £500 and £2,000 depending on the complexity.
- VAT
- Don’t forget to account for VAT (Value Added Tax) in your project costs. Most building work will be subject to 20% VAT unless you qualify for reduced rates, such as on renovations of buildings over 10 years old.
How to Save Money on Your House Extension
- Opt for a Simpler Design
- Simpler designs without complex architectural features will cost less. Consider using standard materials like brick or block, which are often more affordable.
- Manage the Project Yourself
- If you’re confident in your organisational skills, consider managing the project yourself to save on the costs of hiring a project manager. However, make sure you have the time and knowledge to oversee the build properly.
- Shop Around for Quotes
- Always get multiple quotes from contractors to ensure you’re getting a competitive price. Make sure to check reviews and references before hiring anyone.
- Consider Prefabricated Extensions
- Prefabricated extensions, which are built off-site and then assembled on your property, can often be more affordable and quicker to install than traditional builds.
Final Thoughts
The cost of building a house extension in the UK can range from £18,000 for a small single-storey extension to over £100,000 for a large or double-storey extension. The exact price will depend on factors such as size, materials, location, and labour costs. Always budget for additional expenses such as planning permissions, VAT, and professional fees to avoid any surprises down the line.
Before starting your project, it’s crucial to carefully plan and get detailed quotes from reputable contractors. With the right approach, a house extension can significantly increase your living space and add value to your property.
Looking to start a house extension project? Get in touch with experienced professionals in your area to get the best rates and advice for your home.
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