How to Stake Out the Corners
of a Foundation

Once you have determined the frost depth and chosen a subcontractor who is knowledgeable about the soil in your building lot, you are now ready to stake out the corners of your foundation and approximate the location for your small house.

Survey Tools Say...

Surveyors have some very precise... and expensive... tools to accurately measure where your foundation corners will be. This is definitely a case where hiring a professional to do this is money well spent.

Using a measuring instrument (a 100-foot measure tape works best), some string, stakes, and a hammer or sledgehammer, simply pound in the stakes at the approximate foundation corners and connect with string. This will give you a visual idea of where you're house will sit on the site.

If your foundation will be square or rectangular it will be an easy thing to get it relatively "square" (right angles on all the corners) by measuring corner to opposite corner (there’s also the 3-4-5 method, which I’ll talk about later). Think of a parallelogram. Better yet, compare a square and a diamond shape. If you were to measure from corner to opposite corner in the square your measurements would be the same. Whereas in the diamond you can see measuring one way will always be longer than the other.

So with your four stakes of the foundation corners pounded into the ground go ahead and measure the corner to corner way. Is one distance longer? You're out of "square". Keep moving your stakes and measuring until they're equal.

Admittedly this is an over simplification of how to stake out your foundation. If all the tools you had were an accurate measuring tape and stakes you could probably spend the better part of a day getting it all staked precisely. Fortunately, your excavator has some pretty nifty measuring and surveying tools to get those foundation points in quickly and accurately. Money well spent, in my book.

So, all the excavator will need is to know the exact placement of just one corner, which orientation you want the house in, and then to look at your plans for the measurements on each side. With their surveying tools they will be able to deftly measure distances, angles, and squareness.

Your newly hired excavator will take everything from here.

Older books on building (well, not that old, really) talk about putting up batter boards to define the corners of the foundation. Truthfully, I really don’t see that anymore. Maybe somebody somewhere is doing it, but we didn’t need to do it for my house project. The modern precise laser measuring tools probably negate having to use batter boards.

By the way, there is also the 3-4-5 method of determining a 90 degree angle. It's the basic geometric principle that if you take any unit of measurement (feet, meters, cubits, etc.) and draw a triangle that is 3 units on one side, 4 units on another, and 5 units on the final side, you will always end up with a right triangle. Pretty nifty. Or, you could go to the hardware store and buy right-angled T-square or L-square.