I'd like to avoid having a separate waste going through the wall for the basin, can I use a boss on the horizontal section of soil pipe to connect the basin waste?
Ideally I'd use a 90 deg pan connector with built in basin waste but I'm not sure this is possible as the 90deg would be horizontal, I'm guessing they are intended to be used vertical with the basin waste coming in the top? Thanks.
Edit, added arrows to show the waste directions.