What do you mean by well-built? Adding feature sometimes is just as expensive as (if not more than) replacing insulation or re-pipping. Features like 10 feet ceiling would be very expensive to add.
Well-built = built by someone or an entity who cared about more than just selling the home at top dollar and waiting the statute of limitation on lawsuits out! It can be a year old, it can be 100, and you know it when you see it.
I guess I care less about features than about quality of construction and actual location, ability to walk places, and minimal time spent in the car commuting.
