Site Preparation Checklist: What Needs to Happen Before Breaking Ground

Why Site Preparation Makes or Breaks a Construction Project

Every successful construction project in Oregon starts with proper site preparation. Skipping steps or rushing through site work creates problems that haunt the project for decades: settling foundations, failed drainage, cracked pavement, and costly repairs.

This checklist covers every step from initial planning through the moment your site is ready for construction. Whether you are building a home, a commercial building, or a parking lot, these steps apply.

Phase 1: Pre-Construction Planning

Before any equipment arrives on site, complete these planning steps.

1. Property Survey

Hire a licensed Oregon surveyor to establish:

• Property boundaries — Know exactly where your property ends and your neighbor's begins
• Easements and setbacks — Utility easements, access easements, and building setback lines limit where you can build
• Topographic survey — Elevation data across the property shows natural drainage patterns, slopes, and grade changes
• Existing features — Trees, structures, utilities, wells, septic systems, and natural features

Cost: $500-2,500 depending on property size and complexity. Timeline: 1-3 weeks for survey and plat delivery.

2. Soil Testing and Geotechnical Report

Oregon's diverse soils require testing before construction. The Willamette Valley's clay-heavy soils behave very differently from the sandy soils near the coast or the volcanic soils east of the Cascades.

A geotechnical report includes:

• Soil classification — Clay, silt, sand, gravel, or rock. Each has different load-bearing capacity
• Bearing capacity — How much weight the soil can support. Determines foundation design
• Percolation rate — How fast water drains through the soil. Affects septic design and stormwater management
• Water table depth — High water tables require different foundation approaches and may prohibit basements
• Recommendations — Foundation type, footing depth, drainage requirements, and any soil amendments needed

Cost: $1,500-4,000 for a standard report with 3-6 bore holes. Timeline: 2-4 weeks for field work and report.

3. Environmental Assessment

Oregon has strict environmental protections. Check for:

• Wetlands — The Oregon Department of State Lands (DSL) regulates any work within or affecting wetlands. A wetland delineation may be required ($3,000-8,000).
• Riparian areas — Work within 50-100 feet of streams requires permits and setbacks
• Protected species — Surveys may be required for listed species (spotted owl, salmon habitat)
• Cultural resources — Sites with historical or archaeological significance require special handling
• Hazardous materials — Phase I environmental assessment for commercial properties identifies contamination risks

4. Permits and Approvals

Oregon construction permits vary by county and municipality. Common permits for site work include:

| Permit Type | When Required | Typical Cost | Processing Time | |---|---|---|---| | Grading permit | Disturbing >50 cu yds of soil | $200-1,000 | 2-4 weeks | | Tree removal permit | Removing trees over 6-12" diameter (varies by city) | $50-500 | 1-3 weeks | | Erosion control permit | All projects disturbing soil | $100-500 | 1-2 weeks | | Utility connection permits | New water, sewer, electric connections | $500-5,000 each | 2-8 weeks | | Stormwater permit | Projects creating >1,000 sq ft impervious surface | $200-2,000 | 2-6 weeks | | Driveway approach permit | New access from public road | $100-500 | 1-4 weeks |

Start permits early. Processing times in Portland-metro jurisdictions can extend to 8+ weeks during busy seasons.

5. Utility Locating

Call 811 before any digging. Oregon law requires utility locating at least 48 hours before excavation begins. This is free and non-negotiable.

Utilities to locate:

• Electrical lines (above and below ground)
• Natural gas lines
• Water mains and service lines
• Sewer and storm drain lines
• Telecommunications and fiber optic cables
• Irrigation lines

Private utilities (on your property but not in public databases) may need a separate private utility locator. Cost: $200-500.

Phase 2: Site Clearing

Once permits are in hand, site clearing begins. The method depends on vegetation density and site conditions. See our detailed comparison of forestry mulching vs. bulldozing for help choosing the right clearing method.

6. Vegetation Removal

• Clear all trees, brush, and vegetation from the building footprint plus a 10-foot work buffer
• Remove stumps and roots to a depth of 12-18 inches in building areas
• Chip or mulch cleared vegetation on site when possible (saves hauling costs)
• Protect trees designated for preservation with root-zone fencing

7. Demolition of Existing Structures

If existing structures occupy the site:

• Obtain demolition permits
• Disconnect all utilities before demolition
• Test for asbestos, lead paint, and other hazardous materials (required for structures built before 1980)
• Separate recyclable materials (concrete, metal, wood) from waste
• Properly dispose of all demolition debris at a licensed Oregon facility

8. Topsoil Stripping and Stockpiling

• Strip topsoil (typically 4-8 inches deep) from building and grading areas
• Stockpile on site in a designated area for later use in landscaping
• Cover stockpiles with erosion control fabric or seed with temporary ground cover
• Prevent stockpile runoff with silt fence or berms

Phase 3: Earthwork and Grading

9. Rough Grading

Rough grading establishes the general contour of the site according to the grading plan.

Key objectives:

• Establish building pad elevation — Level area where the structure will sit
• Create drainage slopes — Minimum 2% slope away from buildings, 1% minimum for parking areas
• Balance cut and fill — Minimize soil import/export by using on-site material where possible
• Compact fill areas — Fill material must be placed in 6-8 inch lifts and compacted to 95% standard Proctor density

Oregon-specific consideration: Do not grade during or immediately after heavy rain. Wet clay soils will not compact properly and will create weak spots in the subgrade.

10. Drainage Infrastructure

Install drainage systems before fine grading:

• Storm drains and catch basins — Sized for Oregon's rainfall intensity (typically 2-4 inches per hour design storm)
• French drains — Subsurface drainage around building perimeters and in low areas
• Retention/detention systems — Many Oregon jurisdictions require on-site stormwater management for new impervious surfaces
• Culverts — Where drainage crosses roads or driveways
• Swales and bioswales — Natural drainage channels increasingly required by Oregon building codes

11. Erosion Control

Oregon DEQ requires erosion control measures for any project disturbing 1 acre or more (and many local jurisdictions require them for smaller projects).

Required measures typically include:

• Silt fencing around the site perimeter
• Construction entrance with rock to prevent mud tracking
• Inlet protection for all storm drains
• Seeding or mulching of exposed soil within 7 days of final grading
• Sediment basins for larger projects
• Regular inspection and maintenance logs

Phase 4: Utility Installation

12. Underground Utilities

Install all underground utilities before paving or building:

• Water service — Main line from the street to the building meter
• Sanitary sewer — Gravity-flow pipe to the municipal sewer or septic system
• Storm sewer — Connection to the municipal storm system or on-site management
• Electrical conduit — Underground service from the transformer to the building
• Communications conduit — Fiber, cable, and telephone lines
• Gas line — Natural gas service to the building

Trench specifications: Oregon plumbing and electrical codes specify minimum depths and separation distances between utilities. Water lines must be minimum 30 inches deep (below frost line). Sewer lines vary by slope requirements.

13. Utility Testing

Before backfilling trenches:

• Pressure test water lines
• Camera inspect sewer lines
• Verify electrical conduit is continuous and undamaged
• Document all utility locations with GPS coordinates and depth measurements
• Schedule inspections with the local building department

Phase 5: Final Site Preparation

14. Fine Grading

Fine grading brings the site to final design elevation within 0.1-foot tolerance:

• Final building pad elevation confirmed by survey
• Parking and driving surface grades verified for drainage
• Landscape areas graded to final contour
• Topsoil replaced in landscape areas

15. Subbase Preparation for Paving

If the project includes paved surfaces (driveways, parking lots, roads):

• Proof roll the subgrade with a loaded truck to identify soft spots
• Repair any soft spots with geotextile fabric and additional aggregate
• Install and compact aggregate base material (typically 6-12 inches of 3/4-minus crushed rock)
• Verify compaction with nuclear density testing (95% minimum)
• Confirm grades and slopes before paving begins

16. Final Pre-Construction Checklist

Before vertical construction or paving begins, verify:

• [ ] All permits posted and inspections current
• [ ] Survey stakes mark building corners and property lines
• [ ] Rough grading complete and approved
• [ ] All underground utilities installed and tested
• [ ] Drainage systems installed and functioning
• [ ] Erosion control measures in place and maintained
• [ ] Subbase compacted and tested (for paved areas)
• [ ] Temporary construction access route established
• [ ] Material staging and laydown areas designated
• [ ] Safety measures in place (fencing, signage, protective barriers)

Common Site Prep Mistakes in Oregon

1. Starting without a geotech report — Oregon's clay soils are unpredictable. Guessing on soil conditions leads to foundation failures.

2. Grading during wet weather — Wet clay compacts poorly and traps water in the subgrade. Wait for dry conditions or budget for soil stabilization.

3. Ignoring erosion control — Oregon DEQ takes violations seriously. Fines start at $1,000 per day and can reach $25,000 for significant discharges to waterways.

4. Underestimating permit timelines — Portland-area permits can take 8+ weeks. Start the permit process 3-4 months before your planned start date.

5. Skipping utility locating — Hitting an unmarked gas line or fiber optic cable creates delays, costs, and safety hazards. Call 811 every time.

Get Your Site Ready the Right Way

Cojo handles complete site preparation for residential and commercial projects across Oregon. From initial clearing through final grading, we manage every phase so your construction project starts on solid ground — literally.

Contact us for a free site evaluation. We will assess your property, outline the preparation work needed, and provide a detailed estimate and timeline.

See our commercial project gallery for examples of site preparation and excavation work.