Brittany, I don't know how I missed this... Your local country engineer should be consulted, I'm sure he will be, about your question. I suppose it would have to do with the temps in your area, assuming you are up in Northern U.S., there could be inefficiency in the distance the heat would have to travel with only one shared boiler... not to forget that it either has to travel above ground, ??? or below ground. We're pretend engineers here, at least I am. Good luck with the final result. I know a high school that was built, and the air conditioning/heating unit never worked properly for several years, until they finally one summer, went over the entire system in the roofs, and finally found out that the wrong sensor valves were used in about half of the system. I hope you schools do it right the first time. @@