What thing do we need to do
40 mi² is your answer
They are 4 equal rectangle.
Area rectangle = w * l
5 * 2 = 10 mi² (area 1 rectangle)
then you multiply by 4
10 * 4 = 40 mi²
or
5 * 2 * 4 = 40 mi²
Answer: the cost of the land.
To rebuild you house, you shall need to demolish it and build again from the ground, which will mean that you will have to design it, buy all the materials and construct the new house. But the land remain being the same and, if you do not have a reason to intervene it, it will not be a factor for the cost of rebuilding.
40 winds. To be exact 40.2336 winds. But that’s not really possible so I would say 41 winds.