Backyard 99% effort... House 1%

My problem is I can only build houses for sims I'm actively playing and I have no idea why. I'll have a flash of inspiration for a build but when I try and build random houses it frustrates me no end and I always end up abandoning them out of rage and annoyance. But one of my sims kids is ready to move out out home and I'll be in build mode for hours creating the perfect home for them 😂