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.

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.