How Many Square Feet?

[J Scott]

Okay, this question really isn't that important in the grand scheme of things, but I was thinking about it today, and I'm curious what other people in the business think...

I'm in the process of building my personal residence. I have a lot of people ask what I'm paying per square foot to build in my area. Well, while I'm in the process of nailing down the costs, I don't really know how to calculate a price/sf estimate using those costs.

Let me explain:

- My house has 3 levels (basement, main level, second floor). The *footprint* of each level is 1333 sf (about 12 sf bigger on the second level due to a bump-out). So, you *could* say I'm building a 4000 sf house.

- BUT, the basement only has 700 square feet of finished space. So, does that mean I'm actually building a 3300 sf house?

- AND WAIT, I'm building a 560 sf garage. Does that count as part of the house?

- And what about the fact that my architect says that stairs only count towards the square footage of one level? Given we have 50 sf of stairs going both up and down, does that mean we should or shouldn't count that 100 sf of space in the total?

Since we'd incur 50% of the cost even for unfinished space (grading, permits, foundation, framing, siding, roof, etc), I can't imagine we ignore that cost. But given that unfinished space is a lot less costly than finished space, I can't imagine we give it the same amount of "clout" as finished space.

Yes, it certainly isn't a life-or-death concern...but given that I could argue that my square footage is under 3400 (only finished space, not including garage, not double counting stairs) or I could argue that my square footage is nearly 4500 square feet (including all space plus garage), it makes it pretty tough to analyze my price-per square foot building cost.

For example, if my true costs to build this house is $325K, that means my cost per square foot could range from $72/sf to $96/sf! Not very helpful when someone asks...

So, how does everyone else who builds new construction calculate this out?