There is a lot of variance in cost and much of the total cost will depend on the design itself. For a good high quality new construction, plan on anywhere between $350 to $550+ a square foot. If you want something much more luxurious, then plan on it being maybe a little higher, maybe as high as $600 to $800 a square foot. For remodel/addition projects, you can usually count on the cost per square foot being about half as much as new construction, so about $175 to $250 per square foot for remodeled space.