What as-built documents does an EPC contractor need for solar? This guide breaks down every document in a complete solar EPC as-built package — pile elevation data, tracker row conformance, block-by-block sign-off records, and the common reasons packages get rejected and sign-off stalls.
What as-built documentation does an EPC require for solar construction?
EPCs typically require pile-by-pile elevation data, block conformance summaries, tracker row verification, GPS coordinates for each pile, re-drive documentation, and a final acceptance statement. Documentation must match the EPC Pile Installation Specification. Packages are submitted block-by-block as racking installation proceeds.
The specific documents required for solar EPC as-built submission vary by EPC, project, and racking manufacturer — but the core package is consistent across most utility-scale projects in North America. Here is what contractors need to submit for EPC sign-off at the pile installation stage:
The primary conformance document. Lists every pile in the block with: pile ID, design cutoff elevation, actual measured cutoff elevation, variance (design minus actual), tolerance threshold, and pass/fail determination. Must match the design file pile ID naming convention exactly. Missing pile IDs or naming inconsistencies result in automatic rejection.
A single-page aggregate report for the block showing: total pile count, piles within tolerance, piles outside tolerance (failed), corrective actions open, corrective actions closed, and overall block conformance status. This is the document the EPC engineer uses to issue racking authorization. Without a clean block conformance summary, racking cannot start regardless of how clean the detailed report is.
For every pile that initially failed tolerance: the failure date, original elevation, deviation amount, corrective action taken (re-drive, extraction, deviation request), corrective action completion date, post-correction elevation measurement, and post-correction pass/fail determination. Every failed pile must have a closed corrective action record. An open corrective action in a block's log will hold up the entire block.
Calibration verification records for the GPS rover(s) used to measure pile elevations. Typically required for each day of measurement activity. The calibration record shows the known benchmark elevation, the GPS-measured benchmark elevation, and the difference (verification that the equipment is performing within its rated accuracy).
A signed certification from the contractor's QC Manager stating that the data in the package is accurate, complete, and represents actual field conditions. This certification block is required by most EPC contracts and shifts liability for documentation accuracy to the contractor. The QC Manager's name and license number are typically required.
Pile elevation data in a solar as-built package is referenced to a project datum — typically NAVD88 vertical datum tied to a CORS network or a project-established benchmark. The design elevation file provided by the EPC contains the target cutoff elevation for every pile ID, in decimal feet referenced to the same datum.
The measurement process is straightforward: the GPS rover operator places the rover tip at the pile cutoff (the cut or sawed top of the steel pile) and records a single observation. RTK GPS rovers provide ±0.05 ft (2-sigma) vertical accuracy on a good network connection, which is within the typical pile tolerance requirement of ±0.02 ft only when the network RTK solution is fixed — not float. Always confirm fixed RTK solution before logging pile elevation measurements. A float solution can introduce 0.1-0.3 ft of error, which will cause piles to be reported as failed when they are actually within tolerance.
Beyond pile elevation, single-axis tracker systems require conformance documentation for the tracker row itself after racking installation. This is a separate documentation deliverable from pile elevation and is typically required before the electrical subcontractor can begin module installation on that row.
Tracker row conformance documentation records: tracker row ID, design azimuth (the compass bearing of the row), measured azimuth (verified with a digital compass or GPS bearing measurement), torque tube slope along the row length, tracker motor and sensor calibration records, and commissioning test results showing that the tracker moves through its designed rotation range without obstruction.
Contractors who track pile elevation data and tracker row conformance data in the same system — rather than maintaining separate paper logs for each — dramatically reduce the total number of distinct documentation deliverables and eliminate the risk of submitting pile data for one block with tracker data from a different block.
Based on patterns across utility-scale solar projects, these are the most frequent reasons EPC engineers reject as-built packages on first submittal:
The design file has 412 piles in the block. The as-built report has 409. The EPC engineer counts the piles and finds 3 missing. The entire package is returned with a request to account for the missing piles. Finding 3 missing piles in a 409-row spreadsheet takes hours.
A pile was marked failed in the field. The re-drive was performed the next day. But the post-drive elevation measurement was never logged. The corrective action record is open. The EPC cannot accept the block.
The EPC issued a design revision after pile driving began. The field crew was not notified. The as-built compares actual elevations to the original design file — causing piles to appear failed when they are actually within tolerance of the current design.
The EPC's design file uses "B01-T01-P001" format. The contractor's as-built uses "Block1-Row1-Pile1" format. The EPC engineer cannot cross-reference the two files without a manual lookup table. The package is returned for reformatting.
GPS equipment calibration records are required for each measurement day. The as-built package includes calibration records for 4 of 6 measurement days. The package is returned.
Every common rejection reason listed above is a data management problem, not a field execution problem. The piles are driven correctly. The measurements are taken. The re-drives are done. But the documentation fails because manual processes — paper to spreadsheet, spreadsheet to report — introduce gaps.
Sitemark's solar farm grade verification software addresses each failure mode at the point of data entry. Pile IDs are pre-loaded from the EPC's design file — no manual entry, no missing piles possible. Corrective actions are required before a block can be closed. Design file updates are pushed to all field devices simultaneously. Calibration records are linked to measurement sessions automatically.
The result is a conformance package that is structurally complete — every pile, every corrective action, every calibration record — before it is ever submitted to the EPC. First-time acceptance rates for Sitemark-generated packages are significantly higher than manual documentation processes.
For a practical guide to executing pile elevation verification in the field, see our pile elevation verification workflow for solar construction.
Sitemark builds the full as-built package from field data — pile report, block summary, corrective actions, calibration records — with zero manual compilation.
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