The school has a total of twelve classes with each form having three streams. Each class has a capacity of fifty students. The classes are constructed in such a way that they face each other giving teachers a good view of what is happening inside They are well spaced and have a pavement for easy movement. All classes have a well fixed blackboard. The classes also have Seats and lockers adequate for all students. The classes are fitted with electricity which helps students to study in the morning.
GILGIL DAY SECONDARY SCHOOL has well furnished offices. These offices are housed in different buildings .One building house the office of the principal, deputy principal, bursar, account clerks and one major staffroom for the teachers. The staffroom is fitted with seats and lockers for various subject teachers.. We have other buildings housing departmental offices; Department of Humanity, Department of sciences, Department of Languages, Department of Technicals and the Department of Exams.
Gilgil Day Secondary has three laboratories. Two of the laboratories are for science subjects that is; Biology, Physics and Chemistry and the other one for computer practicals.
The science laboratories are are equipped with relevant equipment for conducting practicals. The computer laboratory is equipped with modern computers which are internet connected. The science laboratories are run by Ms. Lorraine while computer laboratory is run by Mr. Mwangi Alfred.
The school has not yet built a permanent library but they use one class as the library. This library is stocked with just few books. Inside the library there are few seats and lockers where students do their personal studies. It only accommodates very few students thus not very available for all students.
The school has toilets located at different places in the school compound. We have toilets for students both boys and girls. The toilets are easily accessible from the classes. Teachers have their toilets located near the staffroom.
KITCHEN AND DINING HALL
GILGIL DAY SECONDARY SCHOOL has one big and spacious kitchen where the students lunch meals are prepared. The school has employed five cooks who assist in the preparation of the meals. Opposite to the kitchen there is a store where required items are kept. The school has one dining hall whose construction is ongoing. It is estimated that when complete it will be able to accommodate about 2000 students.
The School has a well supply of water. The water supply is fixed with a net- work of taps located at strategic places. There is several water tanks located at various positions in the school compound. This tanks are designed for storage of water and thus ensure water is available at all times.