loop system

Steve-O

I have a job I recently looked at, a garage coverted to a playroom.Between the existing house and the garage there is a slab seperating the two at one piont before slab or when it was accessable they ran the heat and plumbing in this space.The heat is a small hot water loop of base board to the second floor.these pipes are accessable3/4' copper.At the boiler it has its own pump and flow valve.Would it be ok in the garage area to tee off the supply and the return putting azone valve on both supplys and use the one pump or would I have to do a differnt piping arrangement.Any suggeations