House Extension Costs 2024/25

How much does a house extension cost in 2024/25?

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Are you considering adding more living space to your home with a house extension in 2024/25? Understanding the costs involved is crucial for proper budgeting and planning.

House Extension Cost per Square Meter

The cost of a house extension is typically calculated per square meter of new internal space. According to industry experts, the average cost per square meter in 2024/2025 ranges from £1,500 to £3,000 (excluding VAT). This means that a 30m² kitchen extension could cost anywhere between £45,500 and £90,000, plus 20% VAT.

Side Return House Extension inside view of side extension in Surrey UK

House Extension Cost: What You Need to Know in 2024/25

Wondering about house extension cost? House extension costs vary widely. The average house extension price depends on several factors. Single-storey house extension costs differ from double-storey house extensions. Your typical house extension cost might include:

House extension cost per square metre can range from £1,000 to £3,000.

Small house extension cost might start at £20,000, while a large house extension cost could exceed £100,000. Most House extension costs in the UK average around £40,000-£50,000.

New house extension interior view, simple modern room with a plant in view.

What is involved when pricing an extension?

Factors Affecting Extension Costs

While the average cost per square meter provides a general estimate, several factors can significantly impact the overall cost of your house extension:

  1. Type of Extension: The type of extension you choose will affect the cost. Single-storey extensions are generally less expensive than double-storey or wrap-around extensions.
  2. Quality of Finish: The quality of materials and finishes you select can greatly influence the cost per square meter. Basic finishes may cost £1,000 – £1,700/m², while high-end finishes can range from £1,900 – £2,200/m² for a single-storey extension.
  3. Location: Extension costs can vary depending on your location, with higher prices typically found in areas like London and the surrounding regions.
  4. Complexity of Design: Intricate designs, unique shapes, or challenging site conditions can increase the overall cost of your extension project.

Additional Costs to Consider

Beyond the construction costs, there are several additional expenses to factor into your budget:

  • Architectural and design fees
  • Planning permission and building regulation fees
  • Structural engineering costs
  • Site preparation and groundworks
  • Utility connections (e.g., plumbing, electrical)
  • Landscaping and exterior work

Cost Calculation Example

To illustrate the potential costs, let’s consider a 25m² single-storey extension with good quality finishes in an average location:

  • Construction cost: 25m² x £1,800/m² (average for good quality) = £45,000
  • Architectural fees: Approximately £3,000 – £5,000
  • Planning and building regulation fees: Approximately £1,000 – £2,000
  • Additional costs (e.g., groundworks, utilities): Approximately £5,000 – £10,000

Total estimated cost: £54,000 – £62,000 (excluding VAT)Keep in mind that these are rough estimates, and actual costs may vary based on your specific project requirements and location.

Costs Guidline for Budget Extensions to Premium Extensions

Here’s a bullet point list of house extension costs for different sizes, as well as budget and premium extension prices:

  • 20m² extension:
    • Budget: £30,000 – £40,000
    • Average: £40,000 – £50,000
    • Premium: £50,000 – £60,000
  • 30m² extension:
    • Budget: £45,000 – £60,000
    • Average: £60,000 – £75,000
    • Premium: £75,000 – £90,000
  • 40m² extension:
    • Budget: £60,000 – £80,000
    • Average: £80,000 – £100,000
    • Premium: £100,000 – £120,000
  • Budget extension costs (per m²):
    • £1,500 – £2,000 per m²
  • Premium extension costs (per m²):
    • £2,500 – £3,000+ per m²

Please note that these are rough estimates, and actual costs can vary significantly based on factors such as location, design complexity, materials used, and the specific requirements of your project.

Basement Home Extension space for your home build.
Loft Conversion for a Home Extension in the UK
Loft Conversion in the UK
Side Return House Extension inside view of side extension in Surrey UK

Contact us about your Home Extension Project

Whether you’re looking for a 30m2 extension in Hampshire, or a Wrap-around extension in Surrey, or an extensive house conversion in London, our team is dedicated to bringing your vision to life. Get in touch with us today, and let’s embark on a journey of creating spaces that reflect your style and stand the test of time. Your dream home project starts with a simple click or a call – reach out to us so we can guide you the right way.

07754 271410

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Hampshire | Surrey | London UK



07754 271410

Extending your home to fit your future

Get in touch with us at Home Build Extensions, to discuss your house extension project and guide you through the best way to gain the most from your new open space extension, or an extra bedroom for your new born.

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