This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
Note to Student. - For this part of the work, it is of advantage to draw a lot plan. This should show the system of drainage, which, if not included in the Architect's drawings, is often not very satisfactorily studied or understood. This part of the work, however, often depends on local conditions or customs in different towns, and for that reason is not made a part of the general contract. The drainage and water supply are often taken care of by the city or town authorities, the pipe being carried either to the lot line or to the outside of the building wall. The Architect has to ascertain what the system is, and to write his specification accordingly.
A datum* line (if not already given) should be established by the Engineer's level, at the sidewalk curb. This should be obtained for use in making the sketches and plans, and should be referred to frequently. If the first-floor level is determined in the studies with relation to this datum line - or "bench mark," as it is often called - the location of the building will be much more easily determined. If the lot plan is kept separate from the drawings, it can be contoured to show the different levels; and sections can be drawn on the margin to show the slope of the land. This plan can also be used for locating drainage and water and gas supplies.
The parts of the drawings referring to the excavator's work should be as carefully studied as those relating to any other part of the building operations. If possible, borings should be made on the lot before commencing the drawings, so that the character of the soil can be determined.
A few dollars spent by the Owner for borings on the lot and for a careful survey, will be more than repaid by certainty in the excavator's estimate.