Is a north-south facing lot better for energy efficiency in Arizona?

Lot orientation does affect energy efficiency in Arizona. A north-south facing lot, where the long side of the house faces east or west, exposes more wall and window area to intense morning and afternoon sun, increasing cooling costs. An east-west orientation, where the home's longest walls face north and south, minimizes direct sun exposure and is generally more energy efficient. However, many factors matter more or equally, including roof overhangs, window placement and quality, insulation, shade trees, and HVAC efficiency. Builders in planned communities often don't offer lot orientation choices. When viewing homes, note which rooms get direct sun and when, and consider window coverings and landscaping.