How long is a typical due diligence period in a commercial real estate deal compared to a residential one?

There's no fixed or standard length for a commercial due diligence period. It's freely negotiated between the parties based on the complexity of the specific deal, and it varies far more than the short conditional periods common in residential deals. What can be said generally is that commercial due diligence periods tend to run longer than residential ones, because there's simply more to review: existing leases and estoppel certificates, environmental history, service contracts, zoning and permitted use, financial statements, and sometimes engineering or building condition reports.

The nuance worth understanding is that "longer" doesn't mean "generous." A buyer still needs to move efficiently within whatever period is negotiated, since commercial due diligence often involves coordinating multiple professionals, such as a lawyer, accountant, environmental consultant, and engineer, rather than a single home inspector. A period that looks ample on paper can get eaten up quickly once several specialists need access and time to report back.

Rather than assuming any particular number of days or weeks is "normal," buyers should scope the actual due diligence tasks for the specific property first, and negotiate a period that realistically allows for all of them to be completed and reported on before conditions are waived.