I want two basement levels (at least).

So many special things are possible in that different climate down there.

A toilet in every room.

Not so odd I guess, but a wraparound porch that wraps all the way around the house. Hidden doors, interior layout difficult to figure out. Bees in the garden. But mostly so much porch.

If apartment I'd want a top floor studio, one of those huge all one room places with loft and a ladder or staircase to the roof so the roof would be the porch. Plants, shade up there too.

Treads. Ever seen/read Mortal Engines? Being a traction city sounds very easy when there is no competition. I'm gonna be the new Oberbürgermeister of the Great Hunting Grounds

Urinal in the garage with direct back yard access. My friend has that at his dad's house. Excellent for backyard barbecues.

Cool air piped to four-poster beds so my ground source heat pump has to act on the minimum volume for maximum efficiency.

A workshop with a smithy.

A hot tub, even if I have to redneck engineer it.

An small modular reactor. Off-the-grid energy for the whole town!

Stone vaulted cellar.

A slide. I've always wanted a slide and I've been super vocal about it.

Corpses. Legally acquired corpses buried und the house, maybe some in hidden departments throughout the house. Just to fuck with whoever owns it after me

A bog ass telescope! That or a zeppelin baloon.

A water fountain (bubbler) on my fiancee’s side of the bed.

I just want the Hey Arnold! room, but with cloudy weather for life.... And reinforced glass because of third world country.

The computer and VR room would just be a huge open space. Allowing for things to have plenty of room, cooling, and rearranged on a whim. I'd have someone even make some roller sofa chairs that I can put into a giant closet when not in use on one side of the room. I'd end up spending like 90% of my nonsleeping time in this wonderful room.

Underground lab or walk in greenhouse.