The basement bath was plumbed for shower, toilet and one vanity/sink when built in year 2000. There is a vent line for the shower but none for the toilet or the vanity sink. No problems with drainage or odors.

Does one vent for this bath meet plumbing codes generally?

That said, I want to add a second vanity/sink in a small room next to the existing bathroom. The new vanity would located on the wall common with the left side of the existing vanity. I need to tie-in to a 1 1//2 inch pvc drain pipe for the existing vanity(to a 2 inch line in cement floor). This would require a pvc pipe run left for one foot to a corner, then a right around the corner and a 3 foot run to the tie-in spot.

Assuming no problems with one vent pipe, would this hook-up meet code requirements? If not what would be required to meet code requirements?

Thanks,
Nicker1