1 Average salaries graph: This graph shows average salaries for this role based on the salaries of jobs posted to reed.co.uk in the last three months. 2  Salary trends graph: This graph shows average salaries over the last 6 months based on a snapshot of jobs advertised on reed.co.uk in the last week of each month. Average salaries graph: This graph shows average salaries for this role based on the salaries of jobs posted to reed.co.uk in the last three months. 2  Salary trends graph: This graph shows average salaries over the last 6 months based on a snapshot of jobs advertised on reed.co.uk in the last week of each month.
1 Adding a basement to an existing house can cost $30,000-$70,000 or more, depending on the size of the existing crawlspace or half-basement or if the house is on a slab foundation, and how much of the work is do-it-yourself and how much is done by contractors. In warmer climates where the foundation does not have to be as deep (typically 18-20 for a crawlspace or a few inches for a slab foundation), including a basement adds more to the total cost of the house because it requires a lot more additional excavation, far beyond what would be done without a basement.
The most cost effective way to add space to a home is to finish the basement. Finished basements can cost anywhere from $10 to $30 per square foot depending on the finishes, mechanicals required, and whether you take on the role of the owner-builder/general contractor.