Find the property line at the street. This will usually be marked by stakes or will be even with the inside of the sidewalk. Measure back from this line the required set-back distance. This is often 25', sometimes more, and rarely less. It should be shown on the plot of the subdivision, or you can get the necessary information from the place where you get the building permit. If there is no exact requirement, use your own judgment, but do not get the house too close to the street. At any rate, establish the front line of the house and stretch a strong string from the points marked "A" and "B" on the accompanying sketch. Then measure back the full depth of the house, set the stakes marked "C" and "D," and stretch a second string parallel with the first one.

You now have the front and rear lines of the house. Then decide exactly where the front of the house is to be and drive the stake "E" directly under the string, driving a nail in the top of the stake to mark the exact corner. Then measure the full length of the house and set the stake "F"; you now have the front corners of the house established. Always drive a small nail in the top of a stake to fasten the string to and to give much more accuracy than is possible by just tying the string to the stake.

Perhaps the easiest way to find the rear corners is to attach a string at "E" and with the aid of a steel framing square estimate the location of the corner "H." Then you can measure from "H" along the rear line to 'T' to find the approximate location of the rear corners. Then check the diagonals to see how far you are off from the correct location. Then a little adjustment of the rear stakes can be made to get the diagonals to come out exactly even. If the opposite sides of the building are equal, the diagonals will be exactly equal when the building is square.

A more scientific method of getting the building square would be to drive a stake at "G," exactly mid­way between the front and rear building lines. Then measure the distance from "G" to the first corner at "E" and swing the tape around until the same dis­tance intersects the rear line at "H." Then measure from "H" to "I" and locate the final rear corner. Then check the diagonals to see that you have done your work correctly. This should give accurate re­sults the first time without having to move any stakes. A slight shift is, however, often necessary. The final check is always to measure the diagonals from "E" to "I" and from "F" to "H."

Any porches, projections, or cut-out corners can then easily be measured from the square which you have established for the main part of the building.

In order to preserve the corners thus found, set witness stakes at the points marked "J," "K," "L," and "M." These stakes together with the stakes first set at "A," "B," "C," and "D" will make it possible to replace any stakes that somehow get moved or rooted out during the process of excavation.

The corners are often marked with what are called batter boards. These are of two types as illus­trated. They must be set exactly level. This is most easily done with a transit or surveyor's level, but can also be done successfully with a two-foot carpenter's level. Find a straight piece of 2" x 6", attach the level to it at the center, and use this as a long level. It is a good idea to change ends with this level every other time it is used to compensate for any slight error in the level or crookedness in the 2" x 6". Strings are then stretched between the batter boards to mark the house lines for the excavation for the foundation. If the batter boards are all on the same level, the strings will be level and if stretched tightly will give the level all around the building. The exca­vation can then be made whatever distance is required below these strings.