Neurodoc’s post reminds me that your house is probably covered by the Int’l Residential Code. I am not yet familiar with this code. I’m sure it’s plumbing provisions are nearly idential to the IPC- and AAVs are allowed generally in the IPC (but some jurisdictions do not adopt all parts of the code, YMMV).
Maybe the AAV can be vented to the outside, since it is on an outside wall. This would probably be the best of both worlds (although you will have a patch of thinnly insulated wall whether the AAV is ventilated to the interior or exterior).
[hijack]I better go buy a copy of the IRC- the State of TX adopted it for statewide use, and a couple of friends and I are planning to go into business building houses. Since I am the only licensed engineer in the bunch, I better be ready to supervise all design activities.[/hijack]