Commercial vs. Residential Inspections: What's Actually Different

Over the years, I've had a lot of conversations with business owners and investors who are buying their first commercial property. Most of them come in expecting something close to what they experienced when they bought their house: a few hours, a checklist, a PDF report. And they're surprised when I explain that what we're doing is a different animal entirely.

That's not a knock on them. Nobody tells you this stuff until you need to know it.

The Scope Is Bigger

A residential inspection is structured around a single-family living space. I'm looking at the same categories in basically every house: roof, foundation, HVAC, plumbing, electrical, insulation, windows, doors, and so on. The scope is well-defined.

Commercial properties don't work that way. You might be inspecting a 3,000 square foot retail strip, a 15,000 square foot warehouse, a mixed-use building with apartments above a storefront, or an office building with multiple HVAC systems and a flat roof. The inspection scope gets defined based on what the building actually is.

A flat roof is a completely different inspection than a pitched residential roof. Commercial electrical panels, especially in older buildings, can be complex enough that I involve a licensed electrician in the evaluation. Elevator systems, loading docks, fire suppression systems, commercial kitchen exhaust - these are components that just don't come up in residential work.

The Standards Are Different

For residential inspections, I follow InterNACHI's Standards of Practice. For commercial, the standard that most lenders and sophisticated buyers expect is ASTM E2018, which defines a Property Condition Assessment (PCA).

A PCA is more formalized than a residential inspection. It typically includes:

• A Property Condition Report (PCR) that documents observed conditions in detail
• A cost table that estimates deferred maintenance and capital expenditures over a defined period (often 12 months and 10 years)
• Document review, including any available maintenance records, prior inspection reports, and permits

If you're financing a commercial purchase through a bank, there's a good chance the lender will require a PCA. It's worth knowing that upfront so you're not scrambling during due diligence.

What I'm Actually Looking At

Here's the honest version of what goes into a commercial inspection in Central Wisconsin:

The roof gets serious attention. Flat and low-slope roofs are common on commercial buildings in this area, and they have a finite lifespan. TPO, EPDM, built-up roofing. I check for ponding water, membrane deterioration, flashing conditions around penetrations, and drainage. A failed commercial roof is not a small repair.

The HVAC is often multiple systems serving different zones. I'm checking rooftop units, split systems, unit heaters, exhaust fans, and whatever else the building runs. In Wisconsin, heating reliability isn't optional. A commercial tenant whose space drops below 50 degrees in January has a real problem.

The electrical in older commercial buildings can be genuinely surprising. I've found Federal Pacific panels, undersized service entrances, and amateur wiring that happened over decades of build-outs. I document what I see and flag what needs licensed evaluation.

The structure - this is where local experience matters. Older Wisconsin commercial buildings were often built on piers, crawlspaces, or slabs that have been through 40 or 50 freeze-thaw cycles. I'm looking at the foundation, the load-bearing walls, the floor system, and anything that suggests the building has moved or settled unevenly.

ADA accessibility is documented as an observation item, not a code compliance opinion, but buyers need to understand what's there.

The Timeline Is Longer

A residential inspection takes me 2.5 to 4 hours and you get a report within 24 hours. A commercial inspection might take a full day on-site, and the report, especially if it includes a cost table, takes longer to prepare properly.

If you're in due diligence on a commercial purchase, build in at least two weeks for the inspection process. If the building is large or complex, plan for more. Trying to rush a commercial inspection to hit a deadline is one of the more reliable ways to miss something expensive.

What to Ask Before You Hire an Inspector

Not every home inspector should be doing commercial inspections. The skill sets overlap, but they're not identical. Before you hire someone, ask:

• Are you CCPIA certified or do you have equivalent commercial inspection training?
• Have you inspected this type of property before (retail, industrial, office, mixed-use)?
• Will your report include a cost table for deferred maintenance?
• Will you coordinate with specialists (structural engineer, electrician) if something warrants it?

I'm CCPIA certified and have inspected a range of commercial properties throughout Central Wisconsin. If you're looking at a commercial purchase in Wood, Marathon, Portage, or the surrounding counties and want to talk through what an inspection would look like for your specific property, reach out.

Commercial real estate is a significant investment. You want to know what you're buying before you close, not after.

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Eric Bjorkquist is a CCPIA Certified Commercial Inspector and InterNACHI Certified Professional Inspector serving Central Wisconsin. Reach out at 715-213-4554 or schedule at eandrinspections.com.