Site Analysis Services Across Texas and Oklahoma
A bid is only as good as what is known about the ground under it. IRONWILL Earthworks reads a site the way the people who will have to build it need it read: the public soil survey, the borings, the flood map, the utility record and the walk, assembled into what the earthwork will actually involve before a number is written down.
Short mobilization across the metroplex
Every finding tied to the document that proves it
Sites for GCs, developers, owners and agencies
The same crew can clear, grade and excavate
Every earthwork number rests on something that was either measured or assumed
A cut and fill quantity, a stabilization depth, an undercut, a haul: each one is a consequence of what the ground is. Site analysis is the work of replacing assumptions about that ground with measurements and public records before the design is fixed and the price is committed, so the surprises that move an earthwork budget are found on paper instead of under a machine.
IRONWILL Earthworks is an earthwork contractor based in Dallas. We evaluate a site as the crew that will grade it, which means the evaluation is aimed at the decisions a contractor and a design team actually make: what can be reused as fill, where the water goes, what has to be treated, what is buried, and what a permit will require before the first machine moves.
On this page: what site analysis is and is not, how it relates to the survey and the geotechnical report, the documents that make up a complete evaluation and who is licensed to produce each, the order we work in, what the metroplex's ground does to all of it, and what to send to get started. Every standard named below is linked at the end, with a note on what it governs.
What site analysis is
Site analysis is the assembly and reading of everything that decides how a parcel can be built on: the soils beneath it, the elevations across it, the way water enters and leaves it, what is buried in it, what regulates it, and what stands on it now. Some of that comes from the public record, some from licensed professionals, and some from walking the ground. The product is a set of decisions a design team and an estimator can build against, with each one traceable to its source.
The public record alone answers more than most owners expect. The USDA's Web Soil Survey carries the national soil survey, with maps and data covering more than 95 percent of the nation's counties1. Flood risk comes from FEMA's Flood Map Service Center, the official public record under the National Flood Insurance Program, which searches by address2. Both are read before anyone drives to the site.
What the record cannot answer is answered in the field and in the laboratory. The building code requires soil classification to be based on observation and tests of material disclosed by borings, test pits or other subsurface exploration in appropriate locations, with further study where slope stability, strength, moisture effects, compressibility or expansiveness are in question3. Skipping that step does not remove the risk; it moves the risk to the middle of construction, where it is most expensive to carry.
Site analysis, land survey and geotechnical report: three documents, three licenses
Each is produced under its own professional license and answers a question the others cannot. Site analysis is the reading of all three against what the earthwork has to do.
Land survey
Establishes boundaries, easements, rights-of-way and elevations. In Texas, professional surveying, which the statute defines to include locating real property boundaries and platting and laying out land, may be practiced only by a person registered or licensed under the Occupations Code4. The survey says where the property is; it does not say what the ground inside it will carry.
Geotechnical report
The engineered account of the subsurface. Under the 2021 International Building Code the scope of the investigation, including the number and type of borings, the sampling equipment and the laboratory program, is set by a registered design professional, who must have a fully qualified representative on site during all boring and sampling3. In Texas that professional is a licensed engineer whose seal must appear on the report5.
Site analysis
The contractor's reading of the site: what the survey, the soil survey, the borings, the flood map, the utility record and the walk mean for clearing, grading, drainage, stabilization, haul and sequence. We assemble the stack, coordinate the licensed work the project needs, and translate the whole into earthwork decisions.
| Document | Produced by | What it decides for the earthwork |
|---|---|---|
| Soil survey map and report | USDA Natural Resources Conservation Service, Web Soil Survey1 | Which soil series the site sits on, its clay content and shrink-swell class, and where the boring plan needs to look hardest |
| Boundary and topographic survey | A registered professional land surveyor4 | The limits of work, easements that constrain grading, and the existing surface the cut and fill is measured from |
| Geotechnical investigation and report | A licensed engineer5, to the code's required contents3 | Fill suitability, moisture and density targets, lift thickness, stabilization, undercut and the expansive-soil provisions the pad is built to |
| Flood hazard determination | FEMA Flood Map Service Center2 | Whether any of the site is a flood hazard area, which changes what grading and fill may be approved3 |
| Waters and wetlands screening | Against the Corps of Engineers' definition of waters of the United States6 | Whether a federal permit stands between the plan and the first cut |
| Existing utility investigation | To ASCE 38-22 quality levels, and the one-call system before any excavation78 | What is buried, how confidently it is located, and what must be protected, relocated or designed around |
| Phase I environmental site assessment | An environmental professional under ASTM E1527-219 | Whether recognized environmental conditions exist that change what can be excavated and where it can go |
| Stormwater permit determination | Against the TCEQ construction general permit thresholds10 | Whether the site needs coverage and a pollution prevention plan before construction begins |
What a complete site analysis covers
Soil evaluation
Series and mapping from the soil survey1, then the borings. The standard penetration test, the most frequently used subsurface exploration test in the world, returns both a sample for identification and an N-value that correlates with engineering properties11; the samples are classified under the Unified Soil Classification System by particle size, liquid limit and plasticity index12. From those tests come the questions that decide the earthwork: what is reusable as fill, what must be wasted, and what the pad will need.
Topography and volumes
The existing surface, from the surveyor's topographic work and from our own drone photogrammetry where it helps. A commercial drone flight is a regulated activity: the person at the controls must hold a remote pilot certificate with a small unmanned aircraft rating, keep the aircraft in visual line of sight, and stay at or below 400 feet above ground level13. The surface is what the cut and fill takeoff and the balance are computed from.
Drainage and flood hazard
Where water enters, crosses and leaves the site now, read against the flood map2. In a flood hazard area the code will not approve grading or fill unless it is placed, compacted and sloped to resist shifting and erosion during flooding, and in a floodway not without a hydrologic and hydraulic analysis by a registered design professional showing no rise in flood levels3. Finding that out before design is a grading decision; after design it is a redesign.
Vegetation and existing conditions
Trees, brush, structures, pavement, debris and fill of unknown origin, documented so clearing and demolition are scoped against what is on the ground. Existing fill matters: where shallow foundations will bear on more than 12 inches of compacted fill, the code requires a geotechnical investigation that specifies the material, the compaction test method, the lift thickness, the field density method, the minimum density and the number and frequency of tests3.
Utilities and access
Existing utilities located to a stated quality level. Under the subsurface utility engineering practice the Federal Highway Administration describes, Quality Level D is records and recollection, Quality Level C adds a survey of visible features such as manholes and valve boxes, Quality Level B uses surface geophysics to find the horizontal position of virtually all utilities, and Quality Level A exposes them for precise plan and profile mapping7. Access, haul routes and staging are read at the same time, because they govern the equipment and the sequence.
Environmental and regulatory constraints
Waters and wetlands, screened against the federal definition: wetlands are areas inundated or saturated by surface or ground water at a frequency and duration sufficient to support vegetation adapted to saturated soil6. Recognized environmental conditions, screened under ASTM E1527-21, the standard practice for the Phase I environmental site assessment that satisfies the all appropriate inquiries requirement for federal landowner liability protections9. Both are raised with the agencies before they can become a stop.
How we work through a site
Depth varies with acreage, terrain and what is being built. The order does not. Each step narrows what the next one has to look for, and the licensed work is scoped from the desk work rather than guessed at.
Site walk and field measurement
We walk the property and measure what the paperwork did not show: wet ground, exposed rock, old fill, drainage paths, tree cover, structures, access and the neighbors. Where the surface matters we fly it, under Part 10713.
Subsurface program
Borings and laboratory testing scoped by the engineer3, with the boring plan informed by what the soil survey and the walk showed. We coordinate the geotechnical firm and make sure the questions the earthwork needs answered are on its list.
Surface, drainage and volumes
Existing and proposed surfaces compared, cut and fill computed, shrink and swell applied from the report, and drainage read with grading, because on most clay sites they are the same problem.
Findings, recommendations and handoff
We walk the results with you and the design team: what the ground will support, what has to be corrected or treated, what the earthwork involves, and what each of those does to the schedule. Every finding points at the document that proves it.
What a site analysis protects you from
The risks below do not disappear when the evaluation is skipped. They wait until construction, when a change is priced by the day rather than by the page.
Foundation performance
Bearing, moisture behavior and expansiveness determine whether a foundation stays where it was built3.
Pad design
Elevations and soil data are what building pads and grading plans are drawn against.
Drainage
Water problems found before design are grading decisions. Found after construction, they are repairs.
Quantity certainty
Unsuitable material, rock, haul distance and over-excavation are the surprises that move an earthwork budget.
Design accuracy
Architects and engineers draw to measured ground rather than assumed ground.
Excavation safety
Knowing what is buried, and notifying the one-call center before excavation, is the law and the first safety control8.
Schedule
Scope discovered mid-project moves every date behind it. Scope discovered early moves none.
Why the metroplex's ground makes the subsurface program non-negotiable
The Blackland Prairie's signature soil, Houston Black, is a very deep clay weathered from calcareous mudstone, 40 to 60 percent clay in its control section, with high shrink-swell potential and cracks half an inch to four inches wide that open to a foot or more deep in dry periods; its permeability is very slow14. The building code's own test for expansive soil is a plasticity index of 15 or greater with more than 10 percent passing the No. 200 sieve and more than 10 percent finer than 5 micrometers, or an expansion index above 203, and much of the region's clay clears those thresholds easily.
That is why the evaluation happens on the property and across it rather than at one point. The plasticity index, from the Atterberg limits tests, is used with other properties to correlate with compressibility, permeability, compactibility, shrink-swell and shear strength15; the expansion index is a qualitative index of swelling potential rather than a design number16. Where the code requires it, the geotechnical report must carry provisions to mitigate the effects of expansive soils and special design and construction provisions for foundations on them3. More on the regional detail in why North Texas clay soils make proper grading non-negotiable.
Shrink and swell in expansive clay, read from the record and the borings
Moisture-sensitive subgrade and lift placement
Rock and unsuitable material that change haul and handling
Wet-weather schedule risk and erosion control
Who site analysis is for
Anyone about to commit a design or a number to a piece of ground: general contractors, developers, owners, design teams and public agencies.
General contractors
Site packages where the earthwork line is the one most likely to move, and the GC wants the ground read by the contractor who will have to stand behind the quantity.
Commercial developers
Retail, office, medical and mixed-use sites where earthwork quantities drive the pro forma and a bad soil assumption becomes a change order.
Industrial and logistics developers
Large footprints where uniformity across the pad is the specification and the soil survey, the borings and the drainage have to agree before the slab is drawn.
Architects, engineers and surveyors
Design teams that need real ground conditions, elevations and constraints before drawing to them, and a contractor who can speak to constructability.
Municipal, county and federal work
Public and infrastructure projects where the investigation, the report and the earthwork are specified, inspected and documented to public standards.
Land buyers and holders
Anyone evaluating what a parcel needs before it can be built on, before the commitment rather than after it.
Have a property you’re evaluating?
Send the address and acreage, a plan set if you have one, or just tell us what you intend to build. We will tell you what the analysis needs to cover, which licensed work the project requires, and what it takes to get the site build-ready.
Site analysis across Texas and Oklahoma, from Dallas-Fort Worth
We evaluate commercial, industrial, multifamily, municipal and federal sites across Texas and Oklahoma, from infill parcels to raw acreage. Crews and equipment are based in Dallas, and the work can start the day the plans arrive.
This part of the work needs no crew on site, so ask about a parcel anywhere in or near the region.
Property address and acreage
What you intend to build
Plans, plat or survey, if you have them
Prior soil or environmental reports
Target schedule and known constraints
Site analysis FAQ
What is site analysis in construction?
The assembly and reading of everything that decides how a parcel can be built on: the public soil survey1 and flood map2, the survey, the geotechnical investigation3, the utility record7, the environmental and permit screens, and the walk, turned into earthwork decisions that each point back to a document.
How long does a site analysis take?
How is a site analysis different from a Phase I environmental site assessment?
A Phase I is one document in the stack: an environmental professional's records review, site reconnaissance, interviews and report under ASTM E1527-21, aimed at recognized environmental conditions and the federal landowner liability protections9. Site analysis reads that alongside the soils, the surface, the water and the utilities to decide what the earthwork will involve.
Do I need a site analysis before getting architectural plans?
Yes. The code requires the geotechnical report at the time of permit application, with the boring logs, the soil profile, the water table if encountered, the foundation recommendations, expected settlement and the expansive-soil provisions3. Plans drawn before that exists are drawn to an assumption, and they are revised when the report arrives.
What is the difference between a site analysis and a land survey?
A land survey fixes boundaries, easements and elevations and may be performed only by a registered professional land surveyor4. Site analysis reads that survey with the soils, the water, the utilities and the constraints to decide what building on the property will take. Each needs the other.
Is soil testing included in a site analysis?
Field evaluation is ours; laboratory testing is the geotechnical engineer's, and under the code its scope is the engineer's to set3. We coordinate the firm, feed the boring plan what the soil survey and the walk showed, and make sure the earthwork's questions are on the laboratory's list.
Can a site analysis reveal drainage problems?
Yes, and it is one of the most valuable reasons to do one. Where water enters, crosses and leaves the site is read with the flood map2, so drainage is solved with grading, swales and detention before design rather than repaired after construction.
Does site analysis cover environmental or wetland issues?
We screen for them: waters and wetlands against the federal definition6, flood hazard against FEMA's maps2, recognized environmental conditions under the Phase I standard9, and the stormwater threshold under the TCEQ construction permit, which begins at one acre disturbed or a larger common plan of development10. Findings go to the appropriate professional or agency before they can affect the schedule.
Do you handle the grading and excavation after the analysis?
Yes. IRONWILL Earthworks can take a project from evaluation through clearing, grading and excavation to build-ready land, so the crew doing the work already knows the site.
What information should I send to get started?
The property address and acreage, what you intend to build, any plans, plat or survey you have, prior soil or environmental reports, and your target schedule. An address alone is enough to start the desk work.
Sources
Every number and every rule on this page is cited here. Reviewed September 17, 2026.
- Web Soil SurveyUSDA Natural Resources Conservation ServiceThe single authoritative source of soil survey information, produced by the National Cooperative Soil Survey, with maps and data for more than 95 percent of the nation's counties.
- FEMA Flood Map Service CenterFederal Emergency Management AgencyThe official public source for flood hazard information produced in support of the National Flood Insurance Program, searchable by address.
- 2021 International Building Code, Chapter 18, Soils and FoundationsInternational Code Council, as published in the UpCodes Texas library, 2021Section 1803.3 (classification from borings and test pits, and the conditions that require further study), 1803.3.1 and 1803.4 (the registered design professional sets the scope and keeps a qualified representative on site), 1803.5.3 (the four-part definition of expansive soil), 1803.5.8 (what an investigation must specify where foundations bear on more than 12 inches of compacted fill), 1803.6 (the report's required contents), 1804.4 (site grading) and 1804.5 (grading and fill in flood hazard areas).
- Occupations Code Chapter 1071, Land SurveyorsTexas Constitution and Statutes, Texas Legislative CouncilSec. 1071.002 (professional surveying includes locating real property boundaries and platting and laying out land) and 1071.251 (registration, license or certificate required).
- Occupations Code Chapter 1001, Texas Board of Professional Engineers and Land SurveyorsTexas Constitution and Statutes, Texas Legislative CouncilSec. 1001.301 (license required to practice engineering) and 1001.401 (the seal on every plan, specification or report issued for a project).
- 33 CFR 328.3, Definitions (Definition of Waters of the United States)Code of Federal Regulations, U.S. Government Publishing Office, 2023The Corps of Engineers' definition of waters of the United States and of wetlands.
- Subsurface Utility EngineeringFederal Highway Administration, U.S. Department of TransportationThe four utility quality levels, D through A, and the reference to ASCE/UESI/CI 38-22.
- Utilities Code Chapter 251, Underground Facility Damage Prevention and SafetyTexas Constitution and Statutes, Texas Legislative CouncilSec. 251.002 (excavate includes grading, scraping and ripping) and 251.151 (notice to the notification center not earlier than the 14th day and not later than the 48th hour before excavation, excluding weekends and legal holidays).
- ASTM E1527-21, Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment ProcessASTM International, 2021Records review, site reconnaissance, interviews and report; recognized environmental conditions; the all appropriate inquiries requirement for CERCLA landowner liability protections.
- Stormwater General Permit for Construction Activities (TPDES General Permit TXR150000)Texas Commission on Environmental QualityCoverage for sites disturbing one acre or more, or part of a larger common plan of development that will, and the pollution prevention plan required before construction begins.
- ASTM D1586/D1586M-18e1, Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of SoilsASTM InternationalThe most frequently used subsurface exploration test worldwide; the sample for identification and the N-value used for design.
- ASTM D2487-17e1, Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)ASTM InternationalClassification by particle-size characteristics, liquid limit and plasticity index.
- 14 CFR Part 107, Small Unmanned Aircraft SystemsCode of Federal Regulations, U.S. Government Publishing Office, 2023Sec. 107.12 (remote pilot certificate with a small UAS rating), 107.31 (visual line of sight) and 107.51 (operating limits, including 400 feet above ground level).
- Official Series Description: Houston BlackUSDA Natural Resources Conservation ServiceVery deep clay from calcareous mudstone; 40 to 60 percent clay; high shrink-swell potential; cracks 0.5 to 4 inches wide to 12 inches or more; very slow permeability; the Blackland Prairies.
- ASTM D4318, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of SoilsASTM InternationalThe Atterberg limits and their use to correlate with compressibility, permeability, compactibility, shrink-swell and shear strength.
- ASTM D4829-21, Standard Test Method for Expansion Index of SoilsASTM International, 2021The expansion index as a qualitative index of swelling potential rather than a design parameter.