Conducting site investigations is an important part of construction projects to gain valuable information that can be used during the design and planning phases. A thorough site investigation report provides key details about the existing conditions and limitations of a construction site. This sample report outlines the process and findings of a site investigation conducted for a proposed new commercial building development.
Project Details
The proposed development is located at 123 Main Street in a suburban area. The site is a vacant 0.5-acre lot bordered by Main Street to the north, residential properties to the east and west, and a small wooded area to the south. The project consists of a new three-story 30,000 square foot commercial office building with associated site work including a parking lot, landscaping, utilities connections, and stormwater management facilities.
Purpose and Scope
The purpose of the site investigation was to assess existing site conditions that could impact the design and construction of the proposed building and site work. Key aspects investigated included the following:
Topography and drainage patterns to determine adequate stormwater management approaches.
Soil conditions including type and bearing capacity to establish foundation and earthwork requirements.
Underground utilities to identify potential conflicts and relocation needs.
Existing vegetation to determine what could be incorporated into the landscaping plan.
Adjacent properties and uses to consider interface issues.
Environmental and regulatory constraints.
Field Work and Observations
The site investigation field work was conducted over two days in October. Weather conditions were sunny with temperatures in the mid-60s Fahrenheit. Observations and readings were recorded using field notebooks, surveying equipment, soil test pits, and vegetation identification guides.
Topography – The site has a gentle northeast slope of approximately 3-4% toward Main Street. Drainage currently sheet flows toward the front and sides.
Soils – Test pits excavated to 5 feet depths revealed sandy loam topsoils underlain by dense sandy clay subsoils. Standard Penetration Test blow counts ranged from 10-30 indicating medium to dense consistencies. No groundwater was encountered.
Vegetation – Mowed grass and sparse shrubs/trees currently cover the site. Adjacent woods are predominantly deciduous hardwoods. Select trees along the perimeter could remain.
Underground Utilities – Only a 4-inch water main exists in Main Street. No utilities were found on site. Nearby utilities include telephone/cable and 12-inch sanitary sewer in an easement to the south.
Adjacent Properties – Single family homes 20-40 feet from the east and west boundaries. Large yard/open space to the south behind woods. Commercial uses across Main Street.
Regulations – Site is zoned General Commercial. No wetlands, floodplains, or other environmental constraints identified based on records research.
Analysis and Recommendations
Based on the site investigation, the following analysis and recommendations were developed:
Foundation – Shallow spread footing foundations are suitable bearing the medium dense sandy clay subsoils. Allowable bearing capacity is 3000 psf.
Grading – The northeast slope can be maintained to direct drainage toward Main Street. Limited cut/fill anticipated (<3 feet). Stormwater - Best Management Practices including rain gardens and infiltration trenches along the perimeter are recommended to meet water quality treatment requirements. Detention is also needed for rate control. Utilities - Water and electric are available from Main Street. Sanitary sewer connection should be from the south easement. Phone/cable will require coordination for service extension. Landscaping - Existing perimeter trees along east and west boundaries are in good condition and can remain. Extensive new plantings are recommended to screen parking areas and enhance buffers to neighbors.
Regulatory Compliance - No wetlands or environmental permitting is anticipated. Zoning setback requirements will dictate building and parking lot placement. This site investigation provided invaluable input for the design team to consider the existing conditions and limitations at this site. The analysis and recommendations identify the key factors to address during schematic design to develop a constructible site plan that is compliant with regulations and protective of surrounding properties and natural features. Further investigations may be needed as design progresses, but this initial study lays the groundwork. This site investigation report example demonstrates the level of detail needed to document existing conditions and analyses from a construction site evaluation. Thorough investigations upfront save money and headaches down the line by surfacing potential issues that can be addressed early in the design process rather than as surprises in the field. With proper documentation, site investigations empower design and construction teams to make informed decisions from the inception of a project.