Easily enough, by modeling myself in a year from now and anticipating what my most likely preferences will be at the time. It's imperfect, of course, but it's quite a bit better than nothing.

Regarding making us as humans happy, I definitely factored that into my analysis. That's why I not only compared the value of each individual part of the house (kitchen, backyard, bedroom) but also the use of that part of the house. For example, the backyard is not really usable for half the year (not counting the view question, which was a separate component of the evaluation). The original first choice house had a gorgeous back yard, and both of our attentions was drawn to it. However, then we sat down and mathed it, and realized we would only enjoy it half the year, decreasing its total value by half. This is an example of how future-oriented thinking helped avoid a problematic decision that would undermine my total happiness.