I dug this up
2.5.9. Air Admittance Valves
(See A-22.214.171.124.(1) in Appendix A.)
126.96.36.199. Air Admittance Valve as a Vent Terminal
1) Individual vents may terminate with a connection to an air admittance valve as provided in Articles 188.8.131.52. and 184.108.40.206. (See also Sentence 220.127.116.11.(1).)
18.104.22.168. Air Admittance Valves
1) Air admittance valves shall only be used to vent
a)fixtures located in island counters,
b)fixtures that may be affected by frost closure of the vent due to local climatic conditions,
c)fixtures in one- and two-family dwellings undergoing renovation, or
d)installations where connection to a vent may not be practical.
2) Air admittance valves shall be located
a)not less than 100 mm above the horizontal branch drain or fixture drain being vented,
b)within the maximum developed length permitted for the vent, and
c)not less than 150 mm above insulation materials.
22.214.171.124. Installation Conditions
1) Air admittance valves shall not be installed in supply or return air plenums, or in locations where they may be exposed to freezing temperatures.
2) Air admittance valves shall be installed in accordance with the manufacturer`s installation instructions.
3) Air admittance valves shall be rated for the size of vent pipe to which they are connected.
4) Installed air admittance valves shall be
b)located in a space that allows air to enter the valve.
5) Every drainage system shall have one vent that terminates to the outdoors in conformance with Sentence 126.96.36.199.(1).
You can use an Air Admittance Valve in a existing house renovation. Just make sure you place it under the bar so it can be replaced as needed.