Ernest Solvay and Émile Waxweiler founded the Institute of Sociology in 1901 at Leopold Park as part of the expansion of the Université Libre de Bruxelles (ULB). Designed by architects Constant Bosmans and Henri Vandeveld, the institute was completed in 1902.

The building, designed on a basilical plan, features a central nave-like main hall illuminated by lateral and overhead light, flanked by side wings with study cabinets and two-story rooms at the rear. Its main roof is pitched, while the side wings have flat roofs. A semi-circular room topped with a terrace juts out from the lower level on the south facade, facing the park.
Unlike the Avant-Garde style of the earlier institutes built on Leopold Park, the structure is entirely built in white Euville stone with traditional masonry punctuated by windows, though a metal framework supports the roof, with arches resting on gallery-level metal elements. The entrance facade is an eclectic and elegant composition with a central pedimented section flanked by square turrets, while the pond-facing facade boasts pilasters, a dentil frieze, and an overhanging cornice. A colonnade forming a ground-floor gallery enhances the lateral facade, completing the harmonious design.

Despite most ULB institutes relocating to the Solbosch campus in the interwar period, the Institute of Sociology remained at Leopold Park until 1967, later housing the ULB Press until its abandonment in 1981. Left vacant and vandalized for several years, it was thankfully classified as a monument in 1988 and finally restored in 1993-1994 by Francis Metzger and Luc Deleuze. The careful restoration was crowned by several awards, including the 2012 Europa Nostra EU Prize for Cultural Heritage.

Renamed “Bibliothèque Solvay”, it is now managed by a private event management firm, making it difficult to see it outside of rapidly sold out heritage day visits… and the occasional concert.
The images shown here date from September 2023.