It's very common for new buildings to use RTU's. Your old school probably didn't do it for a few reasons. The old plant may not have enough capacity and to me the most obvious, would be that the work involved was probably not worth it to connect the 2 buildings. If you go back and re-read the thread, I've posted numerous links of new construction that show your theory is %100 wrong. Why you choose to continually ignore everything that everybody in here is telling you... I have no idea.