The sexton's school
For a long time education was a matter for the church. In 1575 the chaplain ran the school in Diegem; after that usually the sexton, sometimes helped by the parish priest. It did not always go well: in 1593 the schoolmaster was a brewer who was summoned to court and stayed away, after which his son kept the school open. By 1610 the dean was very pleased with the class for boys and girls. An appointment of 1710 asked the sexton to teach the young ‘reading, writing, arithmetic, singing, good morals and manners’. The poor table paid the school fees of poor children; in 1732 the books were the Mechelen catechism and the life of Our Lady.
The municipal school
Until the mid-19th century the teacher taught in his own house. In 1854 the town hall was built with a classroom, and in 1858 a separate classroom was added behind it. It did not go without quarrels: in 1855 a saddler complained that the master had beaten his son until he bled, and the mayor and a councillor found a stinking cesspit on their visit. The teacher answered the mayor rudely, and the council suspended him for a month without pay. In 1864 a second class was added, with a teacher who could teach French, ‘of great importance for a municipality at the foot of the capital’; in 1869-1871 a girls' class and sewing lessons followed. In 1880 school fees were abolished.
In 1900 Diegem-Lo got its own classroom on the Zaventemsesteenweg, and a second in 1903. During the First World War the oldest pupils were given time off to plant and lift potatoes and pick peas. After the war the municipality built a new boys' school on the Zaventemsesteenweg, to plans by the architect Jacobs; the building stands on 62 concrete piles, which cost an extra 200,000 francs, and it opened after Easter 1926. Later came a nursery class (1959), supervised evening study (1960), new pavilions (around 1965) and a crèche (1965).
The library
As early as 1 October 1869 Diegem started a public library, probably in the new town hall and school. It later moved to the municipal school and in 1970 to the cultural centre. The headmaster was usually also the librarian. The state recognised the library in 1923; in 1980 it had 8,903 books and 194 readers.