The question "What makes a good floor plan?" turns out to be very hard to answer because many subjective and mysterious issues arise. Even so, there are objective rules you should consider when planning a house (which, like all rules, are meant to be thoughtfully broken). While important, these rules only get you to first base. A really good plan reflects an attitude about living, materials, space, the human condition — all issues for another column (or book). Gather in the light. Make sure light is available where and when it is needed. In the Northeast, where I practice, spirits sag during the frequent cloudy days. South light is essential in this climate, with east light a close second. West light