How do I find out if Air Admittance Valves (AAVs) are allowed in my municipality?
Your municipality's Building Department will be really helpful for this sort of thing.  At least in the USA, some cities are small enough that they do not have their own building department but may use the counties instead.  Either way, they will know what codes apply for your property and can get you the correct answer.

Ask to speak to one of the residential building inspectors. Simply calling on the phone is probably enough, though they may have certain rules about when an AAV can and cannot be used and talking to them in person may make it easier for you to explain your situation (a picture can be a thousand words).

They will want you to get a permit.  This is not a bad idea and in my City it is pretty cheap if you are the homeowner and doing the work yourself.  If you really do not want to get a permit you can still ask them about it since you are simply in the planning stages now and tell them you will pull the permit once you actually start working on your project.