A site visit is most important for the Building Designer so they can fully comprehend all natural and adjoining built structures at the site.

In office discussion and colaboration with owner and or client and builder if required.
Initial site visit to identify possible on site problems and design constraints, consider cooling breezes and position of setting summer sun, determine views and privacy requirements, consider best site position and critical elementA.
Research client's specific requirements as necessary.
Consider and note all adjoining natural and or built structures.
Note fencing and landscape features.
Photograph vacant site for reference.
Prepare client requirements list.