One of the things we like to do for summer work projects in chapter houses is to shut down a "slice" of the house and renovate it. Since it is the summer, the houses are rarely full, so we don't lose any rental revenue.
What I mean by a slice, is a vertical section of a house. Think of a three story house with a long corridor and twelve rooms per floor. One slice would be the four end rooms on the second floor and the four end rooms on the third floor. From the basement, we run conduits straight up, so that one set of conduits feeds the four rooms on one side of the corridors, and the other set feeds the four rooms on the other side. Once we have the vertical conduits, then we run more conduits to the appropriate parts of the rooms. It is generally easier to open up a floor and drop down for a light or sprinkler. Floors are easily "hidden by carpet, while ceilings require replastering and painting.
We can run the network and other low voltage wiring ourselves. But we need a licensed person for the electrical, fire alarm, and sprinkler. But since the conduit is there, they can easily run their pipes and wires in the existing conduits, and they don't have to spend time and effort opening up walls. When done, we just screw down plywood covers in the floors, and for the vertical parts, we have a painted wood cover, and hopefully it is in a closet. You need a bunch of conduits, since you usually can't mix low voltage, power and alarm wires in one conduit. The additional conduit for sprinkler just makes it easy to run the pipes.
Obviously, the first floor can be tricky, since usually first floor walls don't line up with the bedrooms upstairs. But bear in mind the tax consequences. Try to run as much of your conduit in "educational spaces" since they are tax deductions. And if you are a creative fund raiser, have your alumni each sponsor a sprinkler head or stretch of conduit.
Often, a contractor will play ball, and let you do most of the work, and only do the hookups. This will save a lot of money, especially if you let them work "casual" in the summer. Casual means a crew finishes up early one one job and comes over for a couple hours on your job.
Sprinklers can have pvc pipes in places.
In cold weather areas, sprinklers can be heat traced so they don't freeze.
Each state and city has a different building code, so you have to examine all the nuances, and check with your national. They may have some tips.