How do you add a washing machine to your condo next to the bathroom?

The easiest way to do this, is to tie into the drain below the lavatory piping as it connects to the vertical pipes in the wall.Cut in the tee for the washer below the tee for the lavatory.Run the 1 1/2" or 2" pipe horisontaly to the washer location,and add a p-trap of the same size.If the p-trap is inside the wall, you will need a solid or glued trap,and if outside the wall it is fine to use a union trap.From the trap, bring the stand pipe up to 40" off the floor,for the washer drain hose.The proper slope of the pipe from the tee fitting to the trap is 1/4" per foot up to the trap, and the maximum length of a 1 1/2" pipe is 6 feet.The maximum length of a 2" pipe is 8 feet.