I've actually thought about this a good bit.
If I were at all able to, I'd build. Honestly, I don't trust anything made in the last 50 years to stand up under a multi-generational timeframe without it turning into the Ship of Theseus. I certainly wouldn't build with sticks, either-- what's bouncing around in my head right now is a timber-framed ferrocement construction. You don't, strictly speaking, need timber framing, or much of any framing, if you do ferrocement the right way, but it's a suspenders-and-belt thing. And I love timber framing. (For the look: think Tudor or traditional German/Swiss style, only instead of stuccoed brick/wattle-and-daub in that lovely timber framing, the wattle is steel and the daub is latex-concrete: ferrocement.)
I'd build it south-facing, with lots of glazing-- I'm in the northern hemisphere and consider solar heat a must, unless you give me a big enough woodlot. Even then, I'd rather solar: there are better uses for a woodlot than firewood. (Sugar bush, nut and fruit orchard, food forest? Go nuts!) Actually, I'd really like that woodlot.
* If urban, at least a double-lot for an Urban Farm style homestead. If by-laws are onerous, the front yard is an orchard, and they can suck it: apple blossoms are beautifully ornamental. The back yard is my business in just about any city I've heard of, fortunately.
*Rainwater harvesting off the roof, because city water will fail after a day or two without pump power, and storms happen. Besides, why pay a bigger water bill than necessary?
* A full workshop; carpentry and blacksmithing/metalwork, because those are awesome hobbies that can bring in cash for taxes. I'm sure my descendants would agree.
* A library/study. It might not be confined to one room. My apartment is practically this; there's barely a wall without a bookshelf, and I love it. Public libraries are all well and good, but! If I'm in this for the long haul, my town might get taken over by libertarians, or just go broke-- I don't want them going book-less a couple generations down the line.
* A full kitchen, pantry, root cellar. You said homestead, didn't you?
Ironically enough, I'll have no descendants to enjoy passing on this well-thought-out demesne. I'd have leave it to a collateral branch, alas.