Although it would be great to have a certain number, the construction cost per square foot is not even a general number. There is so much to be taken into consideration like the quality of work, and the type of things being included in the price. To give you a number would be very subjective and not realy help you move forward.
My guess is that you are looking to get an idea of what a job would cost. My suggestion would be to get several quotes from some qualified contractors so you have an idea of where they fall based on the same specs being quoted with everything being broken down and itemized. I have a few contractors that I refer business to and they are wonderful at giving you an idea of what the job would cost with everything broken down so that you can decide based on cost if you want something specific. Things are somewhat slow and there is some good competition on prices to bring them down a bit.