Welcome to our article on the average costs for double-storey extensions in the UK. If you're considering expanding your living space, it's essential to have realistic expectations about the expenses involved.

This guide examines the average costs of double-storey extensions, providing valuable insights to help you plan your project effectively. Understanding the financial implications is crucial whether you want to add an extra bedroom, create more living space, or build a multi-functional area. Visit to discover the cost of developing your dream double-storey extension in the UK. 

But remember, costs can vary significantly based on several factors, including location, size, complexity, and materials used. By examining the average costs for double-storey extensions in the UK, we aim to equip you with the knowledge to make informed decisions and avoid unexpected financial hurdles.

So, if you're ready to explore the costs of doubling your space, let's explore what you can expect when embarking on a double-storey extension in the UK.

Factors That Affect the Cost of Double-Storey Extensions

Several factors come into play when estimating the cost of a double-storey extension in the UK. Understanding these factors can help you make more accurate financial projections and avoid any surprises along the way. Here are the key factors that influence the overall cost:

1. Location: Your property's geographical location has a significant impact on the cost of a double-story extension. Areas with higher property values and construction costs will naturally increase overall expenses. Additionally, accessibility to the site and local building regulations can affect the complexity and price of the project.

2. Size and complexity: The size and complexity of the extension also play a crucial role in determining the cost. More significant extensions require more materials and labour, directly impacting overall expenses. Complex designs or unique architectural features may require specialised expertise, leading to higher costs.

3. Materials used: The choice of materials for your double-storey extension can significantly influence the cost. Opting for high-quality materials and finishes will generally result in higher expenses. It's essential to balance aesthetics, durability, and budget when selecting materials.

4. Structural considerations: Depending on your home's existing structure, additional structural work may be required to support the double-storey extension. This can include reinforcing the foundation, adding steel beams, or making other structural modifications. The extent of these requirements can affect the overall cost of the project.

5. Plumbing, electrical, and heating systems: If your double-storey extension involves adding new rooms or relocating existing utilities, plumbing, electrical, and heating systems will incur additional costs. These costs can vary depending on the complexity of the installation and the materials used.

By considering these factors and consulting with professionals, you can better understand the cost implications of your double-storey extension project. This knowledge will help you set realistic expectations and develop a comprehensive budget.

Average Costs for Double-Storey Extensions in the UK

Now that we've explored the key factors that influence the cost of double-storey extensions let's delve into the average costs you can expect in the UK. It's important to remember that these figures are estimates and can vary depending on the factors above. However, a general idea of the average costs can be a helpful starting point for your planning process.

According to industry data and construction experts, the average cost for a double-storey extension in the UK ranges from £1,500 to £2,500 per square meter. Remember that this figure only includes the construction cost and does not account for professional fees, planning permission, or other associated expenses.

To provide a more tangible example, consider a standard double-storey extension measuring 5 meters by 5 meters and totalling 50 square meters. Based on the average cost range, the construction cost alone would be between £75,000 and £125,000.

It's important to note that this figure is a rough estimate and can vary based on the factors mentioned earlier. Additionally, prices can differ between regions within the UK, with London and the South East generally being more expensive than other areas.

By understanding the average costs, you can better assess the feasibility of your double-storey extension project and make informed decisions regarding budgeting and financing options.

Cost Breakdown: Materials and Labor

When budgeting for a double-storey extension, it's essential to understand the breakdown of costs between materials and labour. This knowledge will help you allocate your budget effectively and make informed decisions throughout construction. Let's examine the typical cost breakdown:

6. Materials: On average, materials account for around 40% to 50% of the total cost of a double-storey extension. This includes building materials such as bricks, concrete, timber, insulation, roofing, windows, doors, and finishes. The choice of materials will impact both your extension's cost and overall aesthetic.

7. Labour: The remaining 50% to 60% of the cost typically goes towards labour, including skilled tradespeople such as builders, carpenters, plumbers, electricians, and decorators. Labour costs can vary depending on the project's complexity, the expertise required, and the prevailing rates in your area.

It's important to note that these percentages are approximate and can vary depending on the specific requirements of your double-storey extension. Detailed quotes and estimates from contractors and suppliers will give you a more accurate breakdown of costs.

Tips for Saving Money on Double-Storey Extensions

While a double-storey extension can be a significant investment, there are several strategies you can employ to save money without compromising on quality. Consider the following tips to make your project more cost-effective:

8. Careful planning and design: Thoroughly plan and design your double-storey extension before commencing construction. Making changes mid-project can be costly, so having a clear vision from the start is essential. Engage with professionals to ensure your design maximises space and functionality while minimising unnecessary expenses.

9. Obtain multiple quotes: Seek quotes from various contractors and suppliers to ensure you're getting competitive prices. Be sure to compare the inclusions and exclusions in each quote to make an informed decision. However, remember that the cheapest quote may not always provide the best quality, so balance cost and expertise.

10. Consider alternative construction methods: Explore alternative methods to reduce costs without compromising quality. For instance, modular construction or timber frame systems can be more cost-effective and time-efficient than traditional brick-and-mortar methods.

11. Reuse and repurpose: Consider reusing and repurposing existing materials and fixtures. Salvaging items such as doors, windows, or flooring can reduce costs while adding unique character to your extension.

12. Timing: Consider the timing of your project to take advantage of potential cost savings. Construction demand and material prices can fluctuate throughout the year, so scheduling your project during periods of lower demand or when prices are more favourable can help reduce costs.

By implementing these cost-saving strategies and working closely with professionals, you can optimise your budget and achieve a high-quality double-storey extension without breaking the bank.

Conclusion and Final Thoughts

Expanding your living space through a double-storey extension can be a transformative and rewarding experience. However, it's crucial to have realistic expectations about the financial implications involved. By understanding the average costs for double-storey extensions in the UK and considering the factors affecting the overall expenses, you can make informed decisions and plan your project effectively.

Remember that costs can vary depending on location, size, complexity, and the materials used. Obtaining detailed quotes and estimates from professionals will give you a more accurate understanding of the costs specific to your project.

A double-storey extension offers many benefits, including increased living space, improved functionality, enhanced property value, and the ability to stay in your desired location. By carefully considering the cost implications and implementing cost-saving strategies, you can confidently embark on your double-storey extension journey.

So, whether you're looking to create a new bedroom, expand your kitchen, or build a versatile multi-functional space, understanding the average costs for double-storey extensions in the UK is crucial to making your dream home a reality.