How would I install an additional sink in a 1 sink bathroom? There is plenty of room, as far as counter space. How easy or difficult is it to install a new pipe that leads to the additional sink? The counter is made of wood so it would be easy to cut out the sinkhole.

If you can mount the new lavatory in the same counter top then you may use the same trap and vent for it. Use a 1 1/4" contentious waste, (see image) to connect the sink and use a three way angle stop, (see image) to connect the supplies. Regards, Tom