Based on an average rear extension size of 45m², the typical cost of a ground floor rear extension in London ranges from £85,500 to £135,000. In the rest of the UK, the average costs fall between £74,250 and £117,000.
Using these averages, you can estimate the likely cost of your rear extension with the following figures:
- £1,900: Average lowest cost per m² for rear extensions in London and the South East
- £3,000: Average highest cost per m² for rear extensions in London and the South East
For example, if you’re planning to build a small rear extension of 30m², the cost in London is likely to range from £57,000 to £90,000.
So, why is there such a wide range in costs? The final price largely depends on the complexity of the build, including factors such as the type of roof and finishes you choose, the materials used, and the construction company you select to carry out your design.
We highly recommend to get in touch via our project consultant to receive a free quote for your project.
