We visit every site four times in one day: an hour after sunrise, mid-morning, late afternoon, and the last twenty minutes before the sun goes. It is the single most useful day of the entire project, and it happens before anything is drawn.
What the light tells you
Orientation decides where the living space goes, and orientation is not a compass reading — it is a record of when the sun actually clears the ridge, which on a mountain site can be two hours after sunrise. A plan drawn from a survey and a compass will put the kitchen in the wrong place on half of the sites we work with.
What the wind tells you
The second reading is prevailing wind, which determines whether a terrace is usable in the evening. On the Aegean sites this is the difference between a terrace that gets used every night and one that gets used twice a year.
If a room is in the wrong place, no amount of specification will rescue it.
By the end of the day we know where the house wants to sit, which is usually within a few metres of where it eventually does.