Extension Cost Calculator
About the Extension Price Calculator
The extension cost calculator above produces approximate costs of various sizes and types of side and rear extensions with either a pitched or flat roof.
The data is based upon input from a quantity surveyor on real UK home extensions ranging in size from 3x3m to 5x8m. Extensions outside of these sizes are likely to be less accurate.
Price allows for a finished and plastered extension made of block and brick with a standard concrete floor. We’ve allowed for one UPVC door and window, electrical work and one radiator extension from an existing central heating system. Basic decoration has also been included.
Once you’ve determined the sizes and cost you can then calculate the added value of the build, this again is determined regionally to provide you a clear idea of what you can expect your house price to increase by following the build.
These extension costs exclude:
- VAT
- kitchen/bathroom equipment
- Floor coverings
- external works such as drainage, paths and drives
- removal of any obstructions such as sheds and greenhouses.
It should be remembered that the extension building costs displayed are indicative only and quotations should be obtained from reputable contractors.
