How Commercial Solar Companies Work with General Contractors

When a commercial solar project is part of new construction or a major renovation, the solar EPC must coordinate closely with the project’s general contractor. Done right, this saves money and time. Done poorly, it creates expensive sequencing conflicts and warranty disputes. Here’s how LandAir Energy approaches GC coordination on NJ commercial solar projects.

Pre-Construction Integration

The best time to integrate solar into a commercial construction project is during the design phase — not after the roof is finished. Early integration enables:

• Roof structural design accounting for solar dead load from the start
• Electrical service sizing that includes solar interconnection capacity
• Conduit pre-runs eliminating future surface-mounted conduit
• Roof penetration coordination with the roofing manufacturer for warranty
• Inverter pad locations integrated into the building’s electrical room layout

Coordinated Roofing Specification

If solar is part of new construction, the roofing specification should match what solar attachment will work best:

• TPO single-ply (most common NJ commercial) — supports ballasted or mechanically attached
• Standing-seam metal — supports S-5 clamp attachment with no penetrations
• EPDM — supports mechanically attached with rubber boot flashings
• Concrete — supports mechanically attached with anchored bases

For warranty preservation, the roof manufacturer (GAF, Carlisle, Firestone, Johns Manville) often must approve the solar attachment method. We coordinate this during the design phase with both the GC and the roofer.

Electrical Service Coordination

Solar interconnects to the building’s main electrical service. For new construction, sizing the service to accommodate planned solar (plus any future EV charging or battery storage) avoids future expensive service upgrades. The electrical contractor and solar EPC must agree on:

• Main service capacity (typically 480V commercial)
• Backfeed breaker location (where solar interconnects)
• Disconnect placement (utility-required outside disconnect)
• Conduit pathways from solar arrays to inverters
• Inverter installation locations

Sequencing on Active Construction Sites

For renovations or expansion projects on operating facilities, the GC manages the broader construction schedule while we sequence solar install around tenant operations. Typical coordination:

• Solar install scheduled after roof completion but before final occupancy
• Equipment deliveries timed with GC’s material logistics
• Trade conflicts (roofing, electrical, HVAC) resolved through weekly coordination meetings
• Punchlist items handled jointly

Warranty Handoff

At project completion, the GC, the solar EPC, the roofer, and the property owner all have warranty obligations. Clear documentation prevents future disputes:

• Solar workmanship warranty (LandAir typical: 1 year, longer optional)
• Module manufacturer warranty (25 years typical for tier-1 panels)
• Inverter manufacturer warranty (10-25 years depending on brand)
• Racking manufacturer warranty (typically matches module warranty)
• Roof manufacturer warranty (preserved through approved attachment methods)
• GC overall building warranty

When the GC Is Also the Solar EPC

Some larger NJ general contractors are also solar EPCs. This single-vendor approach simplifies coordination but can mask sub-quality engineering or installation if the GC’s solar division is junior. For property owners, the question is: who is doing the actual solar engineering, and what are their credentials? An experienced GC with a strong in-house solar team can be ideal; an experienced GC with a marginal solar division is risky.

For NJ commercial projects, we work routinely with leading GCs — providing the solar engineering and installation while the GC manages the broader project. Coordinated handoffs at well-defined boundaries make the joint project successful.