Building an upstairs extension on a single-storey house can significantly enhance your living space and increase your property’s value. However, the cost of such a project can vary widely based on several factors. Here’s a detailed guide to help you understand the potential costs and what to consider when planning your upstairs extension.

Factors Influencing the Cost

  1. Size and Scope of the Extension

The size of the extension is one of the most significant factors affecting the cost. Larger extensions require more materials, labour, and time, leading to higher costs. The complexity of the design and the number of rooms or features included will also impact the overall cost.

  1. Structural Modifications

Adding an upstairs extension often requires significant structural modifications to ensure the existing building can support the additional weight. This might include reinforcing foundations, walls, and roof structures. These modifications can add a considerable amount to the project cost.

  1. Materials and Finishes

The choice of materials and finishes plays a crucial role in determining the cost. High-quality materials and premium finishes will increase the overall expense. Considerations include the type of roofing, windows, flooring, and interior finishes.

  1. Labour Costs

Labour costs can vary based on the complexity of the project and the region you are in. Hiring experienced builders, architects, and structural engineers ensures quality work but comes at a higher price.

  1. Permits and Regulations

Obtaining the necessary permits and ensuring compliance with local building regulations can add to the cost. Fees for planning permission, building control, and any necessary inspections should be factored into your budget.

  1. Access and Logistics

The ease of access to your property and the logistics of delivering materials and equipment can influence costs. Difficult access might require additional time and resources, increasing the overall expense.

  1. Additional Features

Including additional features such as en-suite bathrooms, custom-built storage, or energy-efficient installations can raise the cost. These features enhance functionality and value but come with added expenses.

Estimated Costs

While it’s difficult to provide an exact figure without knowing the specifics of your project, here are some general estimates based on industry standards in the UK:

Basic Upstairs Extension:

  • Cost per square metre: £1,500 – £2,000
  • Example total cost (20 square metres): £30,000 – £40,000

Mid-Range Upstairs Extension:

  • Cost per square metre: £2,000 – £2,500
  • Example total cost (20 square metres): £40,000 – £50,000

High-End Upstairs Extension:

  • Cost per square metre: £2,500 – £3,000+
  • Example total cost (20 square metres): £50,000 – £60,000+

Steps to Determine Your Budget

  1. Conduct a Structural Assessment

Hire a structural engineer to assess your current building’s foundations and structure to understand the modifications needed.

  1. Get Detailed Quotes

Obtain detailed quotes from several builders and contractors. Ensure the quotes cover all aspects of the project, including materials, labour, permits, and additional features.

  1. Plan for Contingencies

Include a contingency budget (typically 10-15%) to cover unexpected costs or changes during the project.

  1. Consult Professionals

Work with an architect or a professional planner to create a detailed plan and ensure all regulations and requirements are met.

Conclusion

Building an upstairs extension on a single-storey house is a significant investment that can enhance your home’s functionality and value. The cost of such a project varies widely based on factors like size, structural modifications, materials, and labour. By understanding these factors and planning carefully, you can budget effectively and ensure a successful extension project.

Ready to explore the possibilities for your upstairs extension? Contact us today for a detailed consultation and personalised quote. Our experienced team is here to help you every step of the way.