In the Belgian context, the production of Public Mass housing remained limited in scope. Apart from a few well published examples Cité Modèle & Kiel (Braem), Luchtbal (Van Kuyck), Cité de Droixhe (Groupe EGAU), Belgian housing policies focused on the promotion of private homeownership. Mass housing in Belgium took the form of the massive production of private houses, constituting a sprawled urban landscape that has been described as the ‘banlieue radieuse’. Less studied is the short lived but quantitatively significant private production of large scale high-rise apartments. This paper studies the close relationship between the production of these very different forms of ‘mass housing’: low- and high rise, inner-city and suburban. While the public policy context is rather well known, the private developers that produced this landscape have hardly been studied. This paper studies major players (Amelinckx n.v., Etrimo n.v., Extensa n.v.) and the architectural and development models through which they managed to create and capture a vast market of commodified housing. Through the detailed reconstruction of large scale commercial development schemes in Antwerp and Brussels, the paper describes the optimism of these mavericks of the Belgian property boom and recollects the radiant suburban promise they delivered.Although these property tycoons seem to have had little difficulty in luring in the middle classes and in persuading local political boards, today it becomes clear that the premises on the basis of which they sold the suburban dream were imbued with a thin instantaneous optimism that turned out to be too precarious to keep up with the subsequent impact of urbanization. While their activities are mostly remembered for the trauma of their bankruptcy, affecting many small contractors and private investors, this paper will highlight the collective failure to embed these large scale endeavours within enduring and intelligent (public) urban development strategies.