California - Needs

Since no one needs a second home, we designed the house as if we would live there full time, but kept everything as minimal as possible.  Almost every plan we house included a separate guest house because we are so far away from everyone we know, we wanted guests to be able to stay a week with either of us feeling like we're on top of each other.  It also gave us a place for our non-vegetarian friends to eat dead animals without impacting us, and allowed us to not heat that space when no one is visiting.

Our needs for the main house were simple: a bedroom, a bathroom, ample great room space where we'll spend the most time, a small private space for each of us, and enough "mud room" type space to allow for dealing with the endless stream of wet and dirty clothes that comes from living in a very rural location.

The initial plan was for a 200SF guest house and an approximately 1000SF main house, but both grew larger: the final guest house is 325SF (about the size of a larger motel room), and the main house is 1440SF. (Note: both are floor space, not external).

In the main house, the great room is nearly 40% of the total space, and extra space ended up in the entry, much of which is occupied by a stairway.  We also have two big porches: one over the entrance for protection from the weather, and one on the view side as additional fair weather space.  Although the climate is generally conducive to outdoor living, our site is much windier, colder and wetter than in town (we get between 20 and 30 inches of rain year, and in wet years we get more than 40).

The guest house got bigger partly because we thought we'd have to live in it for six months, and partly because we wanted something that a family could really live in for a week.  The additional space went to a sitting area (which motel rooms often lack), and eating area.  The compromise is that the bed is in a separate bed alcove: its will be separated from the main area by a curtain or shoji screen, but you have to crawl over the edge to get in bed (ie the alcove is exactly the size of a king bed.)