This building is to become the main office for High School Batu Pahat. The students who were then studying at the temporary school at Simpang Rantai was then moved to the new school in 1919. The double storey building has 8 classrooms with 4 classes each downstairs and upstairs. Tuan Syed Abdul Rahman al-Kudcy was the principal between 1919 till 1922. From then onwards, the number of students gradually increase above 200 students and the teachers increased to 10. The ever increasing number of students caused the lack of space for some classes. Therefore, in the year 1924, extra blocks of classrooms were built at the back of the main hall. This new block consists of 3 science laboratories and 10 classrooms. It was named Blok Cendekiawan and was used to teach Science subjects.Apart from that, a concrete house was built was the school's principal and was situated about '100 ela' from the main building. The site of the house is now the land for the High School Dewan Besar (New Hall). The vegetation between the principal's house and the main building was mainly rubber trees, so the principal in order to go to school has to trek through the plantation and jungle.