You have a very good point! I've often thought if I built a home for retirement I might have at least one bedroom and bath on a second floor just for guest use and resale value.

That's exactly what we want to do when we build in rural SC. Most of the time, it will just be the two of us, so I'm putting the master on the first floor. The upstairs will just be bonus space. I may not even finish it right away, although I'd like it to be over and done with when we move in.

A different approach to the same situation is to have a separate building on the property. My mother's house is very small, but she has a large barn, and one end of it is finished and insulated, with A/C and heat. It would be a perfect guest house, but it doesn't have plumbing. We are thinking of doing this on our property, since we have a lot of family members that are allergic to dogs and cats. Otherwise, they can't stay with us, or even visit for more than a couple hours. We plan on keeping the 'barn suite' a pet-free zone. Needless to say, we would only run A/C or heat the few times of the year we actually use the space.
The barn could also be a completely different decor than the main house, thus giving us two different styles to work with.

Here too. We built a house in the late 1980's with something similar and I bet I only went upstairs once a week, and we had 2 small children at the time.

Fantastic. My first floor has everything we need like it was a separate house. Upstairs has two suites with own baths and a storage room (that doesn't need to be heated and cooled).The 2 story design not only saves money heating and cooling because I'm just doing the 1st floor....it's the fact that the 2nd story is my first story's attic. That's significant, instead of 135 degrees, it's typical to reach 85. Much less heat load. I do have R19 insulation between floors too. In the winter the 2nd story has seen the 50s when it's like 32 outside, so it's serving as a buffer.

our old farmhouse was arranged to where we only used the upper floors for storage after our son moved out..however..we lost that house in a fire.

I thought about doing this but since we'll have a basement I don't want to live on three levels. But ask me tomorrow and I'll probably have changed my mind! :)

Thought I'd add a pic....

Here is a link that might be useful:

Beautiful house and mesquites!!! You have done a really good job!