I'd design and build concrete shell homes with basalt reinforcement bars and transverse light-transmitting fibers, for the rural and suburban markets, and factory-manufactured home modules that are rack-mounted and transportable via intermodal shipping containers and forklifts, for the urban market.
One of the disappointing things I have learned is that many municipalities limit the visible height of residential buildings from the average grade level to its highest point to only 30 or 40 feet. That means, in combination with the depth of the frost-heave line, that spherical shells are not possible for a family-sized home, and the only feasible tornado-resistant shapes would be severely-flattened ellipsoids and toruses. I had a hypothesis that I really wanted to test regarding the humidity problems experienced with geodesic dome homes, but that one zoning issue makes testing it pretty much impossible.
I have been pretty disappointed with all of the stick-built homes I have ever lived in, with regard to maintenance and infrastructure issues. In short, I'm sick of paying through the nose for cheap, slipshod crap. If I'm going to pay through the nose anyway, I'd rather get something that could survive a nuclear strike on the nearest strategic asset, where I would never have to use a plunger in any toilet because the architect never talked to a master plumber, and never need to tack up visible wires because the existing wiring plan stinks, and also never have to carry the laundry up and down two flights of stairs because no one bothered to minimize the distance between that particular appliance and all the bedroom closets.
I just want to rebel against the existing market conditions in housing. Realistically, I would likely be an abysmal failure in that sector, and would have to return to software development--with my tail between my legs--in less than 5 years. But I'd also get a kickass house out of it, which would slowly reveal its agonizingly severe problems over the following 10 years, which would have bankrupted my company anyway, had it succeeded. Then I'd write a book about my experience, which would sell 30 copies. I'd become a bitter old geezer, and none of my co-workers would talk to me unless they had a question about our crufty, legacy C++21 module that everyone else is afraid to touch. My best friend would be a red Swingline stapler. I would be buried with it. Then concrete shell homes would sweep the nation in a flurry of unexpected popularity. I would get frequent reports about it in "The Special Hell for People Who Don't Really Deserve It, But We Torment Them Anyway, Just for Fun", which would be effectively indistinguishable from my pre-demise existence as a software professional, except Special Hell gets 3.5 weeks of PTO, and Columbus Day off, because even pure evil has limits.~