What would this cost as a per sq ft  roughly?

I would like to add a second story to my existing house and
make about 2,000 sq ft of about 4 bedrooms and bathrooms.
What would this cost as a per sq ft additional roughly?
Regards

Richard,
There is no definitive answer to your question. When it comes
to home remodeling there is no way to answer "What would it
cost per Square foot?" There are too many variables in each
second story addition. Each remodel is custom built for each
individual house & homeowner. Prices can vary thousands of
dollars for what seems to be the same addition on similar
houses.
I think you are asking the wrong question. What you really want
to know is "Can I afford to make the payments on a second
story addition to my house?"

In order for you to get the answer you would have to explore for
more information & that is going to take some effort on your
part. You will have to decide on a multitude of items to include
or exclude from your addition.
If you read my book "Confessions of a Home Remodeling
Contractor" you know that I discuss the myth of "Price per
square foot" & "Asking the right questions" among many other
topics including second story additions.
If you read my book "How to Add a Second Story Addition" you
will learn what it takes to do it correctly & get the best price
available. There is no point in trying to get a cost estimate until
you have decided on exactly what you want.

Sorry to make this sound like a commercial for the books but
letters like yours are the reason I wrote the books in the first
place.
Regards,
Bill Harbrecht