Hôtel Solvay

The restoration of Hôtel Solvay, an Art Nouveau landmark in Brussels by Victor Horta, addressed serious structural and waterproofing issues. Combining traditional craftsmanship with technical innovation, the project offers a compelling model for heritage conservation and sustainable maintenance in Europe.

Hôtel Solvay, located in the historic centre of Brussels, is one of the most celebrated works of Belgian Art Nouveau. Designed by the Belgian architect Victor Horta for the Solvay family and completed in 1903, the building has been listed as a UNESCO World Heritage Site since 2000.

More than 30 years after its last major intervention, the building showed signs of critical deterioration, particularly to the façade and roof, prompting urgent conservation action.

From 2022 to 2024, the project focused on the restoration of the Euville limestone, cast iron detailing, oak joinery, and stained glass. Structural and decorative ironwork was dismantled, treated with zinc protection, and reassembled with precise attention to original techniques. The signature three-dimensional balcony grille was restored piece by piece. The natural slate roof and two large skylights were entirely renovated to prevent water infiltration and improve insulation. A new climate control system, operated by a rooftop weather station, now regulates heat through automated skylight openings.

To guide key interventions, 3D modelling and structural analysis were used in specific areas, such as the bowed bay windows. All phases of the work were meticulously documented, creating a comprehensive technical archive for future maintenance and for other restorations of Art Nouveau buildings. Stratigraphic studies and material analyses also yielded new insights into Horta’s original design principles.

Originally a private residence, the building later housed the Valens fashion house before being granted museum status in 2021. Since then, it has welcomed over 100,000 visitors. As a cultural landmark in the heart of the city, Hôtel Solvay reinforces Brussels’ reputation as the birthplace of Art Nouveau.

The project mobilised a wide range of master artisans: stonemasons, metalworkers, joiners, slate roofers, and glassmakers. Apprentices took part throughout the project, acquiring hands-on experience and sharing insights during guided tours. The restoration was supported by 80% public funding from the Brussels-Capital Region and 20% from the owner, Alexandre Wittamer, whose long-term commitment ensures public access and preservation.

Extensive outreach accompanied the works: public tours highlighted conservation techniques, students visited the building as part of their coursework, and progress was shared via social media. As such, the restoration of Hôtel Solvay sets a new standard for the safeguarding of Art Nouveau heritage in Europe.

 

“The restoration of Hôtel Solvay, a UNESCO-listed Art Nouveau landmark by Victor Horta, combines sensitive conservation with discreet modern upgrades,” the Awards’ Jury highlighted. “By organising public tours during the works, the project celebrated the craftsmanship involved and raised awareness of the value of architectural heritage,” the Jury added.

Contact: Alexandre Wittamer | Hôtel Solvay – Restoration of facade and roof | info@hotelsolvay.be | www.hotelsolvay.be