Usually building are a part of the site design. A building pad/building object would be nice that we can utilize for design.
It would need the ability to set the FF 8" (or what ever the local codes dictated) above the adjacent pavement, landscaping, or sidewalk. It will need the ability to hold the FF and allow grades of what it is adjacent to it. Sometimes the grade along the building may not be a set elevation. The FF should allow for steps in it for buildings built in hilly areas. The garage should be included in the object since pavement will usually be tied to it. The pavement and building pad object should have a pow wow and decide what elevation should be used and have the water flow away from the building or to a trech drain object in front of the garage. Sidewalk, pavement, and landscaping should also talk to the building pad to determine where it is going.
For single family lots on large subdivisions (at least in LA County) a swale should be included around the proposed building and tie into the adjacent roadway. It should allow for the minimum slope of that swale to meet the local requirements. The location of the high point should be determined parametricaly based on the slope of the adjacent roadway (it won't always be the middle of the lot.
