Quick answer
Drawings recording the installed solar configuration and documented changes from the approved design. Submission and verification requirements depend on the project; records do not replace required approvals.
What Are As-Built Drawings?
Answer: As-built drawings record a solar installation’s final configuration, including documented changes from the approved design. They help owners and maintenance teams locate equipment, trace circuits and plan modifications. Requirements for submission, verification and signatures depend on the project and jurisdiction. Recording a change does not approve it: required design revisions and acceptance must be handled separately.
Permit drawings show the proposed work submitted for approval. As-built or record drawings describe the installed work using field records. Confirm what those terms mean in your contract: a drawing compiled from installer markups is not necessarily an independently measured survey. Identify unverified or concealed details rather than presenting them as known precisely.
The NREL operations and maintenance guide, third edition, includes as-built drawings within the documentation maintained for PV operations. Its document-management guidance also calls for equipment records, inspection records and version control. This is an operational reference, not a universal permit or warranty rule.
When the Records Are Needed
Use the project requirements to define the handoff, not a blanket deadline:
- During construction: capture field changes while dimensions and equipment labels are accessible. Photograph concealed work before it is covered, subject to site safety and access rules.
- Inspection and permit closeout: confirm with the authority having jurisdiction which revisions and final records it requires. A changed installation may require a separate approval process.
- Utility interconnection: check the serving utility’s required final configuration and supporting documents. Do not assume a record drawing or passed inspection alone provides permission to operate.
- Owner and O&M handoff: supply the agreed drawings alongside manuals, equipment records, commissioning results and outstanding items.
- Later modifications: establish the current baseline, then verify affected equipment and conditions before designing an expansion.
DOE’s rooftop permitting guidance distinguishes local permitting and inspection from utility grid connection. Confirm both workflows for the actual site.
What a Solar As-Built Package Can Include
Agree the drawing scope, level of verification and delivery formats before installation. These drawing types retain different kinds of information:
| Drawing type | Installed information to record | Changes to reconcile |
|---|---|---|
| Site plan | Equipment locations and connection points | Equipment moved from planned locations |
| Roof or array layout | Module positions, row spacing and orientation | Modules added, removed or shifted |
| Electrical single-line | Circuit topology, conductor and protection details | Changed equipment, conductors or protection |
| String map | Module-to-input assignments and identifiers | Re-stringing or module-level equipment changes |
| Conduit routing | Routes and accessible junction locations | Rerouted conduit and added junction boxes |
| Grounding and bonding drawings | Installed grounding and bonding arrangement | Changed paths, connections or electrodes |
| Equipment schedule | Installed models, ratings and required serial numbers | Substitutions and actual installed identifiers |
Concealed routes deserve particular attention. Record dimensions from stable reference points and associate photographs with a drawing location. A photo without a location or an unscaled sketch may leave the maintenance team unable to identify the route. If a detail remains uncertain, record that uncertainty and the verification needed.
A Field Change Is Not an Approval
Keep the approved plan baseline, field-change record and final drawing revision distinguishable. A useful change-log row contains:
| Field | What to enter |
|---|---|
| Original reference | Drawing number, revision and affected detail |
| Installed detail | Actual configuration, dimensions and equipment identifiers |
| Reason | Site obstruction, substitution or other documented cause |
| Evidence | Field measurement, labeled photograph, installer report or verification record |
| Design review | Responsible reviewer and affected calculations or drawings |
| Approval status | Applicable authority or utility decision, reference and outstanding action |
| Record update | Final drawing revision, date and responsible person |
Ask the responsible designer and authority how to handle a change before treating it as accepted. A clean CAD drawing cannot establish code compliance, structural suitability or electrical compatibility by itself. Nor does updating a 3D model automatically recalculate every affected design result correctly.
Illustrative Equipment Substitution
Suppose a design specifies four 50 kW AC-rated inverters, and a proposed substitution uses two 100 kW AC-rated inverters:
4 × 50 kW = 2 × 100 kW = 200 kW aggregate AC rating.
The totals match, but the designs are not automatically interchangeable. Exact input voltage and current limits, MPPT assignments, output circuits, protection, manufacturer instructions, locations and interconnection requirements still need review. If accepted and installed, reconcile the single-line diagram, string map, equipment schedule and routes with the approved revision and field evidence. This is a hypothetical documentation example, not a reported project or an approval recommendation.
For a conduit reroute around an obstruction, retain the same traceability: identify the original route, measured new route, added junction box and associated decision. Do not silently overwrite the original plan or invent a length from a photograph.
Formats, Responsibilities and Handoff
Designers: use the approved drawing set as a baseline, reconcile field evidence and identify unresolved details. Deliver a clear revision history. If CAD exports are required, agree file versions, layers and a readable PDF copy; file format alone does not prove accuracy.
Installers: record deviations as they happen, including required model and serial identifiers. Capture concealed work while it is accessible. Route changes and substitutions through the project’s review process rather than leaving the reviewer to discover them at closeout.
Sales and project managers: define the documentation deliverable in the agreement, allocate responsibility and explain the handoff to the customer. Do not promise a universal approval timeline, warranty entitlement or automated as-built generation.
Paper redlines, CAD updates and field documentation apps can all contribute to the record. Whichever method is used, distinguish source observations from inferred details, keep the previous revision and control access to project data. Retain current records for ongoing operation and follow applicable contract, legal and owner retention requirements. There is no single retention period applicable to every solar installation.
When preparing a permit package, agree how approved plans, revisions and final records will be connected. Discuss your documentation workflow with SurgePV to evaluate the demonstrated product functions and the deliverables your project requires.
Frequently Asked Questions
What is the difference between permit and as-built drawings?
Permit drawings describe work proposed for approval. As-built drawings record the installed configuration and documented deviations. Keep approval status separate from the record of what was constructed.
Are as-built drawings required for every solar installation?
Requirements vary by authority, utility, agreement and project. Confirm the applicable submission and verification requirements. Accurate final records also serve a useful maintenance purpose when no specific submission requirement applies.
Do as-built drawings approve an equipment substitution?
No. Recording installed equipment does not replace required design review, revised approvals, inspections or utility authorization. Matching aggregate power ratings does not establish compatibility.
How long should the drawings be kept?
Keep current records available for operation and future modifications, with backups and revision history. Follow the actual legal, contractual and owner retention requirements rather than assuming a universal number of years.
Related Glossary Terms
About the Contributors
Solar-industry contributor
Nimesh Katariya contributes to SurgePV content concerning solar project workflows. This profile intentionally does not assert certifications, project totals, seminar counts, or technical-review authority without retained verification evidence.
Editorial contributor · SurgePV
Rainer Neumann is credited as an editorial contributor on SurgePV content. This profile does not assert engineering credentials, project totals, software-testing experience, education, speaking engagements, or media citations because independent verification evidence is not retained in the publication record.
