Washer/Dryer - getting the Board to allow?

I am combining 2 apartments and have asked the board to permit installation of a washing machine in the second apartment where the dishwasher is. The board says there is too much risk of suds that will back up sinks on lower floors (I'm on 9). I proposed a compact washer that uses HE detergent, similar to what I had in a different building nearby. Has anyone dealt with this type of situation? Can anyone recommend an expert/consultant who can opine on the validity of what the board is saying? My architect is saying the that suds are not an issue with the new compact machines and he's done dozens of these, but I think the board wants to hear from someone with plumbing or engineering expertise and I'm not sure where to find that.