When the house or building is very old and dilapidated the city engineer would inspect it and can be declared condemned. That means the house or building cannot be used anymore for it poses a danger to the life and limb of the occupant. The owner of a condemned building has no option left but to dismantle the structure and, if possible, build a new house or building. That is one of the reasons why the structure should be well-maintained. especially for the concrete and the wooden parts.