As-Built Drawings

As-Built Drawings are the final, accurate documentation of a solar project as it was actually installed in the field. Unlike design drawings or permit plan sets—created before construction—As-Builts capture the real-world installation, including all adjustments made during construction, field changes, rerouting of conduits, final equipment locations, and any deviations from the original design.

In the solar industry, As-Built Drawings are essential for project closeout, AHJ inspections, O&M planning, warranty claims, and long-term system maintenance. EPCs, installers, and engineering teams rely heavily on precise As-Builts to validate system performance, support interconnection requirements, and maintain compliance with NEC, AHJ regulations, and utility specifications.

Solar businesses often use design and documentation platforms like Solar Designing or digital field-reporting workflows to streamline As-Built creation.

Key Takeaways

As-Built Drawings represent the final installed configuration of a solar project.
They are critical for inspections, interconnection, O&M, and warranty documentation.
As-Builts reflect real-world adjustments that occur during installation.
They include updated layouts, string maps, conduit paths, equipment locations, and electrical diagrams.
Precise As-Builts improve long-term system performance, troubleshooting, and regulatory compliance.

What Are As-Built Drawings?

As-Built Drawings are revised construction documents that reflect exactly what was installed—not what was originally designed. They include final measurements, equipment locations, labeling, conductor routing, trenching paths, mounting details, and electrical system updates.

In a solar project, these drawings often document:

Final module layout
Updated array boundary or roof plane changes
Revised string maps
Inverter & combiner box locations
Conduit paths and junction boxes
Grounding and bonding points
Utility meter & disconnect placements
Structural changes (rail spacing, mounting hardware adjustments)

They serve as the “official record” of the completed solar installation—critical for operations, inspections, and future system expansions.

How As-Built Drawings Are Created

1. Field Verification

Installers walk the site and document any changes from the original design:

Equipment moved due to obstructions
Roof pitch differences
Changes in racking layout
Updated wire paths

2. Redline Markups

Notes are added directly to printed or digital plan sets to indicate:

“Installed here”
“Moved 6 ft east”
“Conduit rerouted”
“String 4 combined with String 5”

3. Engineering Review

Engineers confirm all changes comply with NEC, AHJ rules, and utility interconnection requirements.

4. Updated CAD As-Builts

CAD designers revise plan sets to match final installation, including:

Updated one-line and three-line diagrams
Revised array layouts
Updated load calcs and voltage drop if needed

5. Final Approval

The As-Built package is submitted to:

AHJs for final inspection
Utilities for interconnection approval
Owners for project closeout documentation

Types / Variants of As-Built Drawings

1. Electrical As-Built Drawings

Includes updated one-line diagrams, conduit paths, breaker sizes, and grounding details.

Related: Solar Inverter

2. Structural As-Builts

Document final mounting configuration, rail spacing, load distribution, and attachment points.

See: Mounting Structure

3. Mechanical / Layout As-Builts

Final panel placement, setbacks, walkways, and obstruction avoidance zones.

Related: Array Boundary Tool

4. Civil / Trenching As-Builts (Ground Mount)

Includes trench depths, conductor routing, combiner box locations, and equipment pads.

5. Utility Interconnection As-Builts

Final utility meter, disconnect, transformer, and point-of-interconnection details.

What As-Built Drawings Typically Include

Final PV module layout
Final stringing configuration
Updated conduit paths
Junction box & combiner positions
Inverter and battery locations
Grounding & bonding points
Labeling & identification numbers
Revised POI diagrams
Equipment serial numbers
Microinverter or optimizer maps
Mounting structure details

Typical Values / Ranges & Technical Considerations

Conduit & Wiring Changes

Often differ from initial design due to field routing.

Installers must follow NEC Articles 690, 310, and 250.

Array Layout Adjustments

Fire setbacks, parapet changes, and unexpected obstructions may shift panel placement.

Voltage Drop Updates

After rerouting AC or DC conductors, updated calculations may be needed.

Use: Voltage Drop Calculator

String Map Revisions

Sometimes strings are rebalanced due to shading or roof geometry updates.

See: Stringing & Electrical Design

Practical Guidance for Solar Designers & Installers

1. Document changes immediately in the field

Avoid relying on memory—take photos, videos, and measurements.

2. Always maintain NEC & AHJ compliance

Even minor deviations must meet updated code requirements.

3. Coordinate closely with engineering teams

Ensures structural and electrical safety remain intact.

4. Use digital tools for consistency

SurgePV supports accurate and traceable design workflows using Solar Designing.

5. Verify shading and performance impacts

Any array layout change should be re-evaluated with Shadow Analysis.

6. Deliver As-Builts before inspection

Most AHJs require them for the final sign-off and interconnection approval.

7. Archive drawings for long-term O&M

They are essential for troubleshooting, expansions, and warranty claims.

Real-World Examples

1. Residential Rooftop Solar

Installers move an inverter and adjust conduit routing due to a structural beam.

As-Builts document the final conduit path, updated inverter location, and NEC labeling.

2. Commercial Flat Roof

A mechanical unit unexpectedly blocks a design pathway.

Array layout is adjusted, walkway spacing is updated, and the As-Built reflects the final layout for AHJ inspection.

3. Utility-Scale Solar Farm

Trenching routes shift to avoid underground rock.

As-Builts document new trench locations, combiner box placements, and updated AC collection system pathways.