Before a foundation gets poured, the site has to be dug out, shaped and ready. We handle site excavation for new homes, shops, additions and small commercial projects, working from your plans and your builder's schedule.
Site Excavation in Boise
Site excavation is the first real work on most building projects. It's everything that happens between a bare lot and a hole that's ready for footings: stripping topsoil, digging the building pad, cutting for the foundation, and trenching for utilities. Get it wrong and the rest of the job fights you. Get it right and the concrete crew shows up to a clean, level site with the right depth and room to work.
We do site excavation in Boise, Eagle, Meridian, Kuna, Star, Nampa, Middleton and Caldwell. We work for homeowners building one house and for builders with a lot or two going at once.
What Site Excavation Includes
Every lot is different, but most site excavation jobs include some mix of the following. On an open subdivision lot, it may be only the site cut, the foundation dig and backfill. On an older infill lot in Boise, it can start with tearing out a house and end with new sewer and water lines to the street.
- Demolition. On infill lots, an old house, garage or slab often has to come out first. See demolition.
- Clearing. Brush, small trees, old fences and debris get removed. See land clearing.
- Topsoil stripping and the site cut. The top layer gets stockpiled for landscaping, and the lot is cut to the plot plan elevations. See site cuts for new homes.
- The building pad and foundation cut. We dig to the depth and footprint on the plans, whether that's a crawlspace, a slab or a full basement. See foundation excavation.
- Utility trenches. Water, sewer, power and gas runs to the house. See utility excavation.
- Backfill and rough grade. After the foundation is in, the soil goes back around it and the lot gets shaped so water drains away and the driveway and landscaping areas sit at the right height.
The Site Excavation Process
1. Look at the site and the plans
We walk the lot and go through the plans with you or your builder. We're looking at the footprint, depth, access for equipment, where the spoil will go and anything that could slow the dig down.
2. Locates and staking
We call Digline (811) at least two business days before digging, as Idaho requires. The surveyor or builder stakes the building corners and elevations. Digline marks public utility lines, but private lines like sprinklers, power to a shop or an old septic tank on a rural lot aren't marked, so we ask what you know is out there. We also check the stakes against the plot plan before digging, so a bumped stake doesn't turn into a house in the wrong spot.
3. Dig
We cut the site to the plan, checking depth against the grade stakes as we go. Precision here saves the concrete crew time later. Any part of the dig 5 feet or deeper that people will be working in gets sloped, benched or shored under OSHA rules.
4. Haul or stockpile
Extra dirt is either stockpiled on site for backfill and grading or hauled off. See dirt hauling. Topsoil and subsoil go in separate piles so the good dirt can go back on for landscaping. Piles stay back from the edge of the dig and out of the way of concrete trucks, framers and material drops. On a tight lot, more of the dirt has to leave, and that adds trucking.
5. Backfill and grade
Once the foundation passes inspection, we backfill in layers and rough grade the lot. Big rocks stay off the walls and any footing drain. The rough grade slopes away from the house and sets the driveway, walks and yard close to their final heights, so the landscaper isn't moving dirt later. See backfilling.
Soil Conditions Around the Treasure Valley
Soil is the biggest unknown on any dig, and the Treasure Valley has a lot of variety. Two lots a few miles apart can dig in completely different ways. Here's what we see most often and how each one changes a job.
- Caliche and hardpan run under much of Meridian, Nampa and Kuna. It's a cemented layer that's slow to dig and can take a breaker or ripper to get through.
- Basalt sits close to the surface in parts of Southeast Boise and Kuna. Hitting rock changes the schedule and the price.
- River cobble and groundwater are common near the Boise River in Eagle and Garden City. During irrigation season, groundwater can be high enough to flood a basement dig.
- Decomposed granite in the Boise foothills digs well but needs care on steep lots, where cuts can slough and retaining walls are common.
- Clay in parts of the valley holds water and gets slick after rain.
On larger homes and commercial jobs, a soils report from a geotechnical engineer tells everyone what to expect. If you have one, we'll read it before we bid.
Weather and Scheduling
Spring and fall rains turn many Treasure Valley sites to mud, and frozen ground in winter slows digging and keeps concrete crews waiting. Summer is dry and dusty, and we water down the site as needed. Our reviews mention getting to the job before the rains came. That kind of timing matters when a builder is trying to get a foundation in before the weather turns.
Permits and Inspections
The building permit for a new home or addition usually covers the excavation. Larger grading jobs, hillside lots and projects that change drainage may need a separate grading or site permit from the city or county. Projects that disturb an acre or more generally need construction stormwater permit coverage too. Your builder or engineer usually handles the paperwork, and we work to the approved plans.
What Site Excavation Costs
The price depends on the size and depth of the dig, the soil, how much material has to be hauled, access for equipment, and whether utilities and backfill are part of the job. Rock and caliche cost more to dig than loam. We give free estimates and break out the pieces so you know what you're paying for.
If you're comparing excavation contractors, make sure each bid covers the same scope, like hauling, backfill and utility trenches. Ask for the contractor's Idaho registration number and read their reviews.
Why Hire Ultimate Excavation LLC
We're an Idaho registered contractor (RCE-65836) based in Caldwell with a 5.0 rating on Google. Customers talk about Tanner's communication, a crew that shows up on time and fair prices. For builders, that means a site that's ready when your concrete crew is. Call (208) 697-2429 or request a free estimate.
