Savonnerie Heymans: a former soap factory turned into a sustainable housing project

Brussels, Belgium Construction and Development, Environment and Resource efficiency, Local social sustainability


Located less than half a mile from the Grand’Place in Brussels, Savonnerie Heymans is a social housing project converted from a former soap factory. The green renovation was led by MDW Architecture who worked to retain all of the historical buildings while improving the energy efficiency and sustainability and adding new buildings as necessary. The project completed in 2011 recreates a real “village” of 42 sustainable accommodations of different types including studios, 1 to 6-bedroom apartments, lofts, duplexes and maisonettes. The Savonnerie is a 100% social housing scheme that provides a variety of spaces echoing the diversity of the people living in the very heart of Brussels.


Located on the site of a former soap factory, the decontaminated land now welcomes a high-density social housing complex that provides a series of private outdoor spaces allowing its occupants to interact easily with each other and creating a convivial, village-like atmosphere.


Issues tackled

When the social-services department of the central Brussels municipality bought the contaminated 70,000-square-foot site of a former soap factory in 2005, it established a competition for the design of subsidized apartments. The winning plan by MDW Architecture, retains the industrial flavor of the property, which dates back to the 18th century, but transforms it into a sustainable oasis of 42 middle-income rentals grouped around three private courtyards. Project architect Gilles Debrun calls the Savonnerie Heymans “a village” that offers protected space for interaction in an otherwise cramped urban setting. Once hidden behind four derelict houses (now demolished), the complex still presents a discreet face to the street—but a welcoming one.

Actors involved

  • MDW Architecture
  • CPAS de Bruxelles

Actions carried out

  • The original chimney of the factory was retained and used as part of the underground garage ventilation system.
  • Each apartment enjoys a glass-enclosed bioclimatic loggias that acts as an acoustical and thermal barrier requiring no expensive/complicated services to run and lowers energy consumption.
  • Insulation was added to the loft building, which improves its performance to passive standards and requires less than 15 kW per square meter per year to heat.
  • The complex also features a collective heating system for the entire site (cogeneration), sanitary hot water heated by 60m² of solar panels on the roof, rainwater harvesting for toilets, and use of natural materials for insulation like hemp fibers and expanded cork.
  • Density is counterbalanced with the incorporation of a number of community amenities, such as areas for social meetings and events, a public Ludothèque (game library), the “Mini-forest” garden, the 3D landscaped park, playground and the main promenade.


Named after its precursor, the Savonnerie Heymans is now a model public-housing complex that provides shared green spaces and amenities in a dense but underserved neighborhood on the rebound that is populated by a mix of ages and ethnicities.

The architects paid special attention to efficient, low-maintenance measures in order to reduce energy costs during and after construction. For example, they wrapped the new buildings with industrial-style metal panels—a reference to the location’s history—backing them with 5′-inch-thick hemp insulation. Then they restored an existing 19th-century steel-frame industrial building, sandwiching a lighter cellulose insulation between a new brick facade and the inner walls, isolating the concrete slabs from the exterior to create a thermal break. This building, which now houses the Savonnerie’s lofts, meets the passive very-low-energy building-performance requirements of the Brussels Institute for Management of the Environment (IBGE) and uses less than 7,300 BTUs per square foot a year to heat. Additional sustainable elements include 646 square feet of solar panels for hot-water heating, and rainwater harvesting for toilets and gardens.

To preserve the Savonnerie’s sense of place, MDW incorporated various remnants of the factory’s industrial heritage. The most prominent, a 131-foot-high brick chimney, rises amid the metal stairways and bridges linking the apartment buildings around it. More than a relic, it is now used to ventilate the underground garage. Similarly, a warehouse from the 1950s was largely demolished to create a playground with a viewing platform. Its surrounding walls were lowered from 33 to 10 feet high, and sections of the old steel beams were preserved as visual artifacts.

Why it works

. Tucked within the heart of Brussels, a city where only 10 to 15 percent of the housing is for low- and middle-income families, the Savonnerie Heymans represents a promising future for a diverse population and ambitiously puts forward the social role that architecture can play today. It promotes a compact city model and how it can successfully recycle itself by combining density and openness.



More information

Former Soap Factory Cleaned Up Into a Sustainable Housing Project in Brussels