Clearly, anyone building a home wants to make sure it is energy efficient. The first step in designing an energy efficient home is considering the site design as it relates to solar energy. Site design includes lot orientation, location of shade trees, site grading, landscaping, and sustainable site development.
Lot orientation: the relationship between the home and the sun, including how the house faces the sun, prevailing winds, views, driveway access, and approach.
Shade trees and shading: the type and location of shade trees and their impact on temperature, wind speed, and solar access.
Site grading: analyzed for proper water drainage and runoff away from the home, driveway, garage slab, patios, and walkways.
Landscaping: considered in the initial design stage in regard to the home's market value and also in regard to limited shading and water control.
Sustainable site development: important to protect the site's natural environment and vegetation with minimal disturbance, but also to maximize solar access and light, minimize erosion and runoff, and control construction waste and follow a recycling plan for materials.
Source: http://timberframeblog.blogspot.com/2009/11/site-design.html by Jeremy Bonin, AIA NCARB LEED AP