Tie Bar Sink to Existing Bathroom Sink Plumbing

Hello. My Husband and I bought a finished home. We are wanting to turn part of an existing room into a wet bar area. The small bar sink will not be used for food of any kind.

There is an existing bathroom with sink, toilet and shower on a joining wall. We are wanting to just saw a small hole through the ajoining wall, through the existing vanity, and tie the bar sink into the existing sink. Can this be accomplished without causing draining, etc. issues?

The way you are describing it, it would not meet the minimum requirements of any plumbing code.

We would to see the layout of the bathroom plumbing, the pipe sizes, and distance and location to each fixture's vent before suggesting what would meet code. A bar sink requires a proper trap and vent, just like any other sink.

Helpful Plumbing Hints for Residential Construction by Bert Polk Plumbing Inspector Lincoln County

There are too many unknowns to give an answer, and you will not know if, or how, it can be done until you open the wall. One thing you cannot do is run the pipe into the lavatory cabinet and connect to its drain line. Even if it were permitted, you would seldom have enough room to do so.