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UnderwritingAugust 7, 2026·7 min read

The 9-Point Solar NOI Underwriting Checklist for Acquisitions

Solar revenue only survives diligence if it's underwritten like any other income line. Here are the nine items we check before we model a dollar.

The NOI Team, Rooftop solar revenue operators at NOI
The NOI Team
Rooftop solar revenue operators

Why a checklist beats a spreadsheet

Solar revenue is not a modeling problem — it's a diligence problem. The model is simple arithmetic. The risk lives in nine physical and regulatory facts about the asset.

The nine points

  1. Roof age and remaining life. Anything under 10 years of remaining membrane life needs a re-roof plan folded into the timeline. A panel array is a 25-year decision on a surface that may not last 25 years.
  2. Structural headroom. Most post-1990 wood-frame roofs carry a modern array without reinforcement. Older flat-roof buildings need a stamped letter before anyone signs.
  3. Utility and tariff. The same array earns wildly different revenue under different tariffs. Identify the utility, the rate schedule, and whether the state allows virtual net metering.
  4. Meter layout. Master-metered, individually metered, or a hybrid — this drives whether residents can be billed directly or whether the value shows up as a common-area offset.
  5. Interconnection queue. Some utilities clear a residential-scale application in 4 weeks. Others take 6 months. This is the single biggest timing variable.
  6. Load profile. Daytime common-area load (elevators, pumps, corridor lighting, laundry, EV chargers) is the highest-value consumption because it never touches an export tariff.
  7. Shading and usable area. Tree canopy, parapets, and mechanical equipment can remove 30% of a roof's usable footprint. Satellite estimates flatter reality.
  8. Lease language. Check whether existing leases allow utility rebilling, and whether the state requires specific disclosure language.
  9. Exit treatment. Confirm the revenue is assignable to a buyer. Non-assignable revenue does not capitalize, and uncapitalized revenue does not build value.

How to use it

Run all nine before you model. If items 3, 5, or 9 fail, the deal doesn't get a solar line. If only 1 or 7 flag, you adjust size and timing rather than walking away.

What good looks like

A clean asset: post-2000 construction, individually metered, a state with active VNEM, a utility clearing interconnection inside 60 days, and lease language that already permits rebilling. On that profile, revenue is live within a quarter of closing.


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About the author
The NOI Team, Rooftop solar revenue operators at NOI
The NOI Team
Rooftop solar revenue operators

We fund, install, meter, and bill rooftop solar for US landlords, BTR developers, and HOAs — then pay owners monthly.

Meet the team
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