A transit level can be used to locate building lines. See figure 2. Use a plumb bob to set the transit exactly over a survey point at one of the corners of the lot. Adjust the vertical angle of the transit so the cross hairs are aimed at the opposite survey point nail. Adjust the vertical angle until the transit is horizontal and zero the transit. Turn the transit 90 degrees horizontally to another survey point. By adjusting the vertical angle you should be able to aim the cross hairs at that point. Do this each time the transit is moved to a new point. Use a tape measure and a transit to measure the setbacks of the building lines from the property lines. Place a transit over one of the survey points so it is in line with one of  the property lines. Use a tape measure to measure the distance from the survey point to the first setback. Rotate the transit vertically downward and adjust the tape measure so the cross hairs of the transit are aligned with the measured distance. Drive a stake in to the ground at this point. Drive a nail into the stake at the precise location where the cross hairs line up with the top of the stake and the measured distance on the tape measure. This stake will be in line with one off the walls of the building. Record the setback on the stake. Adjust the transit so the cross hairs and tape measured distance coincide at the setback of the opposite wall along the property line. Drive in a stake at that point, nail it and record the setback. Place the transit at each setback point established on the property line. Use the transit and tape measure to locate and stake all of the corner points of the building. Depending upon the complexity of the building, setback points may need to be established on more than one property line to locate the building corner points.