The cost of house extensions in London varies significantly depending on factors such as the type of extension, size, materials used, and complexity of the project. On average, a single-story house extension can cost between £1,500 and £2,500 per square meter, while more complex projects, such as double-story extensions, loft conversions, or basement conversions, can range from £2,000 to £3,500 per square meter. These estimates typically include construction costs but may exclude additional expenses like architectural designs, planning permissions, and finishes.
For kitchen extensions, costs may increase if you’re planning to install bespoke cabinetry, high-end appliances, or structural changes, such as removing walls. Similarly, loft and basement conversions may require additional investments in insulation, waterproofing, or structural reinforcement. To get an accurate estimate, it’s recommended to discuss your specific requirements with residential builders in London and request detailed quotes. This ensures transparency and helps you budget effectively for your project.