Brew on Premise is not uncommon. Usually they have steam jacketed kettles that you use. They supply everything (at a very nominal price). You brew on their equipment, use their ingredients, ferment in their carboy/bucket, they generally force carbonate it and then you bottle off of their keg.
Bringing your equipment into their brewery is most likely against the law and/or against their insurance policies. As such, I highly doubt that this is the case.