We had our 3-year township CO inspection today and were told that we need to have smoke / CO detectors that alerted both sixes of a duplex property. 

I have to close, apply for a conditional use verification, get inspection ( requiring wired smoke detectors, other safety features) and get a business license.

Make sure you have smoke and CO detectors in appropriate places, GFCI outlets near water, functioning mechanicals, make sure everything is in good condition and you shouldn't have a problem.

As the saying goes, when there's smoke, there is fire.I trust that you won't take these remarks as condescending since we've already been in contact with each other.

My other issue I think of when it comes to that is I'm in the process of switching everyone over to non smoking. 

Are you installing new smoke alarms?

I don't see a smoking gun as of yet, I don't. 

If they say put up higher railings, additional smoke detectors, etc, complete it promptly and document it.I've been in the landlord business for 20 years, and I've always kept my properties to code and well maintained. 

They don't realize that a lot of what they see is all smoke and mirrors.  

Others have said that it works like charm for noise and smoke.