Partial renovations

I often see houses which are only partly renovated, like this one in the dístrict of Ilinden in the western part of the city. I think the reason is, that the owners of the several apartments within one building don't have to decide together, if renovations will be done or not. So those who think it's necessary and (more important) who have enough money, e.g. install insulation - and the others don't.