Massproduction of segments
In order to make a house more affordable. I suggest making a house easier to build with mass produced (larger but very easy to handle) component, wich the production proces is optimised for so making it all cheaper. These components should be 2.5 to 3 meters tall so it can still be carried by a worker. These segments would have also some sort of snapping machenism so the worker could snap a part into place. This makes building a house faster and cheaper, but also replacing damaged components should be a cakewalk.