Kinda like the real estate mantra: location, location, location.
Foundation, foundation, foundation: the most important thing to having a well-built, structurally sound house.
Today, the workers checked the foundation forms for squareness using the 3-4-5 rule. Of course, the forms were also built so that when the concrete is poured, it's level with the existing foundation.
Everything is so much more involved and detailed than I ever had a clue. The bottom of the footings ditch has to be clear of debris and loose dirt. So the workers had to take a big wet/dry vac and suck out all the dirt, rocks, etc. Then, the foundation pad must have a layer of gravel, followed by a vapor barrier (thick plastic), followed by a layer of builder's sand. Besides tying all the rebar, they also needed to hang anchor bolts prior to the pour.
Everything gets inspected at this point and if the inspector signs off, then we can call in the concrete trucks to pour the foundation.