To find out how many houses were built during the housing boom, subtract the number of houses before the boom from the number of houses after the boom.
Starting number of houses: 1,790
Ending number of houses: 2,696
Number of houses built = Ending number of houses - Starting number of houses
Number of houses built = 2,696 - 1,790
Number of houses built = 906
Therefore, developers built 906 houses during the housing boom.