How many people lived in Diegem in the past can only be estimated from the number of hearths. In 1435 there were 109 houses, in 1480, after war and plague, only 40, and in 1525 again 125. In 1686 there were 46 buildings, including two castles, two shops and two breweries. From 1786 there are precise figures: 664 inhabitants in 1786, 1,035 in 1840, 2,750 in 1900, 4,039 in 1930. The peak was reached in 1970, with 4,933 inhabitants; the 5,000 mark was never reached. At the merger Diegem had 4,603 inhabitants.
Diegem-Uitbreiding
In 1922 the low-cost housing company ‘Diegem-Uitbreiding’ was founded, with Ulric Marga and Corneel De Ceuster among its founders. The first row of 30 houses was built along the St.-Corneliusweg, now the Lodewijk Degreefstraat; in 1930 came 16 houses on the Haachtsesteenweg and 36 on the Uitbreidingsstraat, now the Eugène Blaironstraat, and from 1954 the Schetsveld estate. In all the company built 265 social homes.
Houses make way
At the same time hundreds of houses disappeared. By 1967, 227 houses had been demolished for the expansion of the airport and the municipality had lost almost 113 hectares. In the 1960s and 1970s the interchanges and motorways followed: in 1972 the Ministry of Transport had 115 houses pulled down, among others in the Lostraat, the Haachtsesteenweg, the Lodewijk Degreefstraat and the St.-Katarinastraat. On 10 March 1970 the population rose up at a public meeting when it emerged that another 107 families would lose their homes.