Extension Cost


Extensions can vary greatly in shape, size and therefore budget. Whether you are planning a simple pitched roof extension or a larger project, costs can start to add up very quickly.
Velux offer advice on typical extension costs, which can help you gain an approximation of the build cost: -
'A basic single storey extension would typically cost around £1,000 per square metre but it could be up to £1,600 or more for a more premium two storey extension.
So a 3 x 5 metre extension would cost from £15,000 and from £50,000 for a two storey extension. These costs are just to create a room, they would not typically include the cost of a kitchen or bathroom.
This average cost should cover design through to decorating of standard rooms, but it is worth having a 10-15% contingency to cover unexpected costs.'
There is also a third party Extension Cost Calculator below: -
Here at Extension Drawings Ltd, we can design your extension to meet your budget, whilst suggesting design ideas to maximise your layout.

FIXED PRICES - NO VAT
Our service is high quality yet affordable, with all services priced between £350 and £550.

SURVEY INCLUDED
We will visit your home, take laser accurate measurements and create your drawings on CAD.

FREE DESIGN CHANGES
We include unlimited changes to all our projects to ensure your extension design is perfect for your needs (see T&C's)