Both my elementary schools had portables added in 1996. Each one had a small ESL fire alarm panel (probably a 1500-series) that was tied into the main building’s system (the first school, built in 1974, had an old Simplex system with a 4208 panel tied into a newer one, probably a 2001 at the time; and the other, built in 1971, had an old Gamewell FlexAlarm system.) Both portables had Wheelock MT-24-LSM horn/strobes installed everywhere, even in classrooms, and the pulls were RSG T-bars, along with various ESL and System Sensor smoke detectors. They’d even put alarm signals in the classrooms! I believe the first school’s portable also had an Edwards Adapt-a-bel installed in the hallway as a school bell, tied into the main building’s master time system. Each school had its’ portable attached to the main building in some way; the first one removed a couple of windows on one side and put a doorway there that would go to the portables, while the other had the portables entrance connected to an existing exit doorway.
They still have the portables to this day. The first elementary school became a K-8 school in 2006, so it was necessary to keep it (it’s used for the eighth grade classes currently). After the main building’s Simplex system failed early this year and was replaced, the alarm devices in the portable were left alone, interestingly. After my brother and I left the other school, they added kindergarten (it was formerly just grades 1 to 6), and had it in the portables for a few years, until they removed sixth grade (some time in 2009, I think, all the “regular” elementary schools became K-5, and the middle schools became 6-8.) I think the portable there is currently used for a couple of special ed. classes.