Builders will just skimp where they can to improve their effective profit. Eg: - not painting the tops of doors - not grading slabs for drainage - not followin

Builders will just skimp where they can to improve their effective profit. Eg: - not painting the tops of doors - not grading slabs for drainage - not following basic instructions about hanging a door - carelessly filling the drainage channel with mortar when laying bricks - not cladding a wall properly because you can't easily see it (which then starts leaking water) I wouldn't undertake a large building project without being very well educated beforehand and allowing significant amounts of time to have your nose in things. Maybe you can get builders which will do a good job without lots of oversight, but there is no way to know this before you sign a contract. Buying something already built saves a lot of time and effort, and dramatically reduces cognitive load.