husband I are just built a small 2 bedroom house for retirement. Space (or lack of it) was a big factor. We’ve moved in, and things I love the most:
Walk in shower with a built in tiled bench seat. so you can sit under the shower.
Over head rain- fall style showerhead, as well as hand held one.
Heating under the other bathroom floor tiles. (Husband insisted, I’m glad he did)
and a toilet that washes and dries your bum - I’m never going back.
tvs on the wall that pivot.
when putting in power points put the ones in that have the connection to charge your iphone etc..
Lights under bathroom cabinet (cabinets are wall hung so easier cleaning) - you don’t have to turn on the overhead in the middle of the night when using the loo so much gentler on the eyes.
wall lights over kitchen bench(under overhead camera or shelving) easier to see what I’m preparing etc..
I live in a hot country so fly/mosquito screens on all windows and exterior doors.
Lots and lots of insulation , in walls (Exterior and interior), in roof space. It’s the thing building companies will often skimp on as you can’t see it - but it keeps you warmer in winter and cooler in summer. And reduces noise from outside and internally. It’s not expensive, especially when compared to heating/cooling costs.
ceiling fans - v cheap to run.
An air purifier thingy - with flus, colds covid it just makes sense.
IME, it’s bullshit that light dimmers work better now. I had better ones in the 1990s - and they were shite.
Lots of great suggestions in previous posts!