How much will my extension cost?

At ICE Arch Ltd we will be happy to discuss your preferences and the cost implications, and we work with several quantity surveyor who will cost specific proposals, but before contacting us you may wish to do some research.

Many factors are easily understood – size and shape, the build quality, first-floor as compared with ground-floor, basement and roof-space, demolishing or knocking-through, fittings for kitchen and bathrooms, etc.

Others are less visible – relocating drains and other services, tricky trees, the size and number of doors and windows (they are expensive), party walls, steelwork, and so on.

Homebuilding and Renovating is aimed at self builders but it has useful information for the wider audience and includes the cost calculator at

Be sure to take note of their ‘Terms of Use’ and check the publication date because labour and material costs are going up all the time.

To see more photos of the extension featured in the image, visit