How much will it cost to extend my house?

The cost of extending a home depends on what the addition consists of. The website CostHelper.com gives an average figure of $13,000 to $125,000, but the cost can vary wildly depending on a range of factors.

Adding a bathroom is relatively inexpensive ($3,000-$6,000) if a homeowner is using existing floor space, but it is much more expensive ($25,000-$50,000) if the work is part of an extension. The situation is similar when adding a new bedroom or family room, which can often be done for less than $5,000 as a space conversion, but could potentially cost around $50,000 when the work is performed by contractors as part of an extension.