There are many national averages quoted that seem to range from anywhere in the range of $30K to $70k to finish a standard 1000sq feet basement. However there are many reasons for this wide variation and the first most obvious one is the current state of your existing basement. Older houses with unfinished basements may consist of just damp walls and concrete floors and nothing else. Whereas some modern houses have basements that are partially finished so already have power and plumbing installed and they may even have some framing in place. Therefore there is a lot less work for the contractor to do.
The first thing that the contractor must do is check for moisture and leaks in the basement and foundations. This can cost around $700 to $3,000 depending on what they find and have to repair. They might also have to clear the external terrain if there is any gradient that would encourage water flow into the basement.
Whether you are installing plumbing and electricity can add significantly to the contractor’s bill. Electrical work is going to set you back between $1000 to $1500 for the work and fitments. However where it gets really expensive is when you start adding plumbing for a bathroom.
This is simply because the cost of work below ground is significantly more expensive than it is upstairs where installing a bathroom would be far cheaper. The reason for this are that once you get down beneath the floor you may then be below the sewerage level so gravity will no longer work. In that case you will need some pumps or other techniques to flush the toilet or empty the bath. This makes plumbing bathrooms in basements very expensiveas a toilet alone can cost $3,500 and a bath and sink another $3,000. However remember if you have a sink in the wet bar or the kitchen then these costs will also apply. Furthermore, should you need to clear seasonal flooding by using a sump pump then these can be an additional $10,000.
But it’s not just electrical and plumbing work that is expensive as it will often need to be sub-contracted to licensed specialists that have or can get the required permits to work under the building regulations. All those other bits and pieces also mount up. For example, if you consider the flooring this can be anything from $1,500 for standard carpet to $4,000 for hardwood and that’s not including the moisture barrier underlay.
Interior walls and framing can also cost around a $1,000 and ever door and trim another $150 so it can all start to mount up. However new fire and safety regulation now stipulate that there must be an egress window in every living area especially in bedrooms so this will mean another $3,000 per egress windows as the parts alone are $2,000 and the labor required to make the hole for the window and dig and install the well for the egress window will not be cheap.
