The game has a budget for each city.
I think it would be right if the money placed in the local budget will be spent on the duration of the house.
Spending decisions must be made by the mayor - the player with the highest level in that city, elected to congress from this country. If city haven't so player. Place will empty.
The mayor will have the right to increase the duration of houses, as a % of the value of the house, with a maximum limit of 40%.
And will low property tax for houses