It really depends - typically a slope facing away from the sun in the temperate zone will be more heavily forested - the sunward side can be too extreme in its variation for much beyond scrub to take hold. We chose our siting based on what was best for our environment, and on noticing how the forest didn’t frost in the winter, and kept green and lush on the floor in the summer, when all else was parched. Considerations around daylight etc., followed after choosing a site. The walls facing downhill and up/down the valley are practically all window - the bedrooms, which face the uphill slope, have small windows, which are still large by the standard for housing around us.