As a buyer, you would be wise to go to the City Hall and review all the permits and information on the property. If you have a specific zoning question, it would not hurt to put a call into the inspectional services of the City or Town or look it up in the City/Town ordinances.
Good questions to ask are:
1) Is the neighborhood under any Historical restrictions?
2) Is the property under any special permit restrictions?
3) Is the property currently a conforming property under all current zoning rules?
If the answer to that question is not known for the specific property (i.e. no one has tried to do anything there in a long time, so no one really knows) then ask general questions to see if the property would trigger any conditions.
What type of problem ? Our jobs are Realtors states we must disclose all that we know about a property. If there is a question the city building department or an attorney may be the best resource to help you with this question.
Zoning maps and their criteria are a matter of public record. An agent should know what zone a property lies in and should suggest that a buyer visit or contact the Building and Zoning Department at the government building or City Hall where that office is located. That way the buyer hears first hand what he can or cannot do with the property.
Hope this is helpful.
Prudential Connecticut Realty
The City of Boston is very helpful. There are some great links to maps and regulations at http://www.bostonredevelopmentauthority.org/zoning/zoning.asp
You can search for permits, applications for permits and even decisions which date back a considerable period of time at http://www.cityofboston.gov/isd/building/process.asp
Finding the problem isn't that difficult...it's fixing it that typically presents the major obstacle. Once you know the problem and consider the possible remedies, you may have a decent talking point in your negotiations.
What is the zoning issue that is in question??
Please consult an attorney for a clear response.