Hey Everyone, Thank you for all the helpful posts and replies.. you all have been a huge help to us already! We have a tiny house I'm about to plumb with a hand sink, shower, washing machine and kitchen sink.. all within a 10' run along one wall. I do NOT have the ability to vent through the roof so any vent would exit through the wall, about 6' 6" high. CODE is not an issue, we're outside of city limits, HOWEVER I want a reliable, clean and odor free drain system The question I'm running into is whether to vent each drain (least preferable), use one main vent (less preferable) or AAVs at each P-trap, etc. Here is an image of what it looks like - looking THROUGH the exterior wall at the back of the appliances (using the example of a single vent stack) In this image, I'm showing what (To me) would work with one central vent vertically inline with the lowest part of the drain (the exit to septic), the hand sink (to the left) and washing machine / sink drains (to the right) all tie into that main vent stack. Honestly, I would prefer to put AAVs at each P trap and call it a day... eliminating any need to punch an external wall hole. How should I proceed...?