Excavation is an area of construction that is unfamiliar to most owner builders. It can be a potential snag to the owner builder project as well. Estimating the costs to prepare the building pad is difficult at best and can be disastrous to the budget at worst. Even seasoned professionals underestimate lot prep costs. Be diligent when estimating and managing lot modification on your property.


It is important for the owner builder to get a thorough survey of their property. A survey will show not only property lines but also the topography of the land. Surveyors will be able to mark where the building pad is and how much modification it will need to actually be buildable.

Call Before You Dig

Before the excavation contractor can begin any lot modification, the owner builder must call “Call Before You Dig” or “Bluestake”, etc. Each region has a state regulated, non-profit service that is contacted prior to any digging work. This company notifies the necessary utilities and technicians will come out to the building site and mark the location of any underground utilities. Digging without first marking utility lines is not only dangerous, in most places, it’s illegal. Normally it is a 3-5 day process. Call a little early.

Cut and Fill

What is cut and fill? Cut is removal of excess material. Fill is importation of material to fill in voids. Sometimes this is done without bringing in outside material but simply by taking excess dirt from one area of the property and putting it where it is needed.

This area of excavation is often the one underestimated. If we look at a lot with the naked eye and say, “That’s fairly flat, there probably isn’t much excavation that must be done,” we run the risk of not budgeting enough for lot modification costs. It is better to get the survey done early and have the potential excavators all give a hard bid based on an onsite analysis and looking at the plot plan. If they bid based only on the plot plan, there is an excuse for them to raise the price later as more work is required.

Removal of Substandard or Rocky Material

If the property has extremely rocky soil, it is a good idea to remove excess material. Leftover soil, or “spoils”, has a tendency to end up as back fill material. If there are rocks and heavy debris in backfill, it can damage waterlines, waste lines and conduit. If the soil is too sandy or expansive, it may not be suitable to build on. Substandard soil should be removed from the site.

Layout and Trenching

The concrete contractor, plumber and excavator will work together to not only dig footings but also to dig and backfill underslab plumbing trenches. Sometimes, if you are able, it is easier to manage if one contractor does 2 or more areas of construction. It is not unusual for some larger concrete and plumbing contractors to include excavation in their services. This may even be included in their standard bid.


Laterals are the trenches dug that allow electrical and gas services to be connected to the house from the street. This is normally done after slab prior to framing or just after framing is complete. It is a bad idea to have laterals dug while other exterior work is going on. The owner builder runs the risk that someone may fall in a trench and be injured.

Be certain that the proper safety measures are followed while laterals are underway. The lateral trenches will be open for several days to a couple of weeks. Caution tape should be up EVERY DAY.


Excavation takes place as the first task in the construction process but also continues throughout the build. Each time digging takes place, remember to contact Call Before You Dig. Safety on the jobsite is a key component of a successful project.

After excavation, concrete is the next task in the construction process.