Here we'll talk about one more halacha: renting a house. If somebody rents a house from another person and that house falls down, the owner is obligated to provide the renter with another house for the same term of the lease. If he had a lease for two years and the house fell down midway through, the owner has to provide him with another house for the next year.
If the original house that fell was small, the owner can provide him with a large house instead. If the renter insists that he wants a small house, the owner has to meet the terms of what he originally agreed to. If the owner rented out a small house, he has to provide him with a small house if the renter would like that. The inverse applies as well. If the original house was large, the owner can't tell the renter, “Here, here's a small house instead,” if the renter wants a large one.
If there was one room in the house, the owner can't provide him with a house that has two rooms. If the original house had two rooms, the owner can't provide him with a house that has only one room. If the renter says he prefers the type of house that he originally agreed to, it is the owner's obligation to provide him with that type of house.
Likewise, with the windows, the owner can't give him fewer or more windows in the new house than he had in the original house if the renter insists on the same number of windows that he had in the original house. In all of these cases, a change can be made only if they both agree to it, both the owner and the renter. Otherwise, status quo: whatever was in that original house has to be provided in the second house.