While I enjoy working on house projects at times, I voted it my most hated because without fail, almost every repair or project is 5x the work to fix the fuckups from the asshat that owned this house before me. The vehicles do not have that issue as the current (old) stable was all purchased new.
Case in point. All the wood and tile flooring was fitted around the door casings, instead of undercutting the casing. So I put in new 6-panel oak doors and the bottom detail looks like shit.