Answer
1500 square feet
Work Step by Step
We found the area of the second floor to be 7857 square feet in problem 38. We found the area of the first level to be 10,413 square feet in problem 37. This is more than 16,500 square feet, so the firm will accept this building. The amount of additional area is:
$$ = 10,413\ ft^2 + 7587 \ ft^2 - 16,500 \ ft^2 \\ = 1500 \ ft^2$$
