The first day of on site construction involves putting stakes on the corners of the foundation and painting the exterior wall locations between the stakes. This will tell the excavator exactly where to dig. The site should have been surveyed before it was purchased so there should be survey pins at each of the property corners. These survey pins allow you to know exactly where the property lines are so you can determine where the house sits on the lot in relation to the property lines. Sometimes it is adviseable to hire a surveyor to also locate the corners of the foundation, especially if the property lines are not square with each other or the lot is sloping or the house barely fits on the lot.
Laying out the exterior foundation walls on the ground with paint and stakes is the first on site step in constructing a new home. You need to have the property corners staked by a licensed surveyor before laying out the home outline. This may be done by you if you feel confident or you can hire a civil engineer to do it. Either way, the end result will be a wooden stake placed at each exterior corner of the future foundation, within a few inches of the actual location. It is not critical to be perfect because the bucket of most excavators are several feet wide and they need to over excavate the hole by several feet to allow working room for the foundation form setters.