The zoning question is sitting on my desk and I cannot figure out where a buyer's agent's job ends

The piece this thread has not landed on yet is what "reasonable care" actually looks like when the income is the whole purchase thesis. If the buyer is paying a duplex price for what is legally a single-family house, the income stream is not a bonus feature, it is the collateral for the loan and the justification for the price per square foot. That makes the permitted use a pricing assumption, not a disclosure footnote, and an agent who understood how the client underwrote the deal had enough information to know the question was load-bearing.

The one number I want is the cap rate the buyer used to arrive at their offer price. If they backed into value from two rent streams, then a permitted-use question is not a zoning technicality sitting off to the side, it is the variable that makes the entire valuation valid or fictional. That changes how a court or an arbitrator reads "reasonable care," because the agent's file would show they knew the income mattered to the price, which makes ignoring its legal basis harder to defend as an oversight.

What was the buyer's stated reason for the price they offered?

The division of labor question is the right one to be asking, and the gap you are describing is real.

In my understanding of how agency duty works, the buyer's agent is not expected to interpret zoning code, but they are generally expected to recognize a fact that a reasonable person would find significant to the purchase decision. A property marketed as income-producing in a single-family zone, with six years of rent history and no mention of permits, is that kind of fact. Most agency law frames it as a material fact, meaning something that would affect a reasonable buyer's decision. Courts in several states have found that visible red flags create a duty to investigate further, even when the purchase agreement includes a "buyer to satisfy themselves" clause.

The practical answer you laid out, calling the building department, asking for the certificate of occupancy, confirming the stated use matches the zoning classification, and documenting the result in writing to the client, covers the agent's obligation without requiring them to become a zoning attorney. It surfaces the question. The attorney or inspector then carries it from there.

Where the gap tends to open is exactly where you named it: the agent assumes the inspector will catch it, the inspector assumes the attorney reviewed title and use, and the attorney assumes the agent confirmed the operational setup. Nobody made the fifteen-minute call.

One thing worth confirming with your broker's E&O carrier: some professional liability policies treat undisclosed zoning violations differently depending on whether the agent documented that they raised the question. That distinction can matter a lot if a claim comes later.

For agents reading this who are newer to non-standard use properties, the Guide tab on the Buyer's Agent strategy page covers due diligence scope in more detail.

Are you working through a specific transaction right now, or building out a checklist for how you handle these going forward?

The "buyer to satisfy themselves" clause is doing a lot of heavy lifting in this scenario and courts have been chipping away at it for years, especially when the agent had specific knowledge that should have triggered further inquiry.

What I'd actually want to know is whether the buyer's agent ever asked for the rent rolls and who produced them. In my experience underwriting Cincinnati deals, a six-year rent history handed over without a CO attached is a red flag that any moderately alert person should catch, not a zoning attorney, just someone who's seen a deal before.

Fifteen minutes to call the building department is right, but the more important question is whether that call happened before or after the option period expired.