Sustainable building design through passive measures

Our attention was always focused to conceive and build an African market and not a mall, despite the important scale of the building and the attention to comfort. Building with climate: the project develops bioclimatic and passive principles, such as thermal mass or natural ventilation through the brick façades like moucharabiehs. These façades also protect the pedestrian walkways from the sun. The concrete structure of the open-air market protects naturally from solar radiation; the different heights of the concrete sunshades let the hot air evacuate naturally. The users, vendors or clients always keep contact with the neighborhood, nature and the sky, which is important to find bearings in space and avoid feeling lost.

Efficient construction and operations

The building uses two construction materials: concrete and brick. First, concrete is available in the Democratic Republic of Congo, as a local resource and skill base. It also fits the structural constraints (load, strength, durability, solidity, maintenance) for such a large building subject to climatic variations. Second, brick is used traditionally in Congolese architecture. For the construction, we reactivated three brick factories within 60 km of the site. Due to bioclimatic conception, there are very few energy expenses, and we eliminated secondary contractors (materials are used for structure as well as finish). The building is low-tech, including the minimum of technical appliances (slopes, not lifts).

Landscape & Biodiversity Integration

Living with nature: we worked on two levels of natural resources in this project – attention to the water and to living species, plants or animals. Concerning the water system, the project includes a network for rainwater recuperation directed to tanks, to water the patios, fight fire or clean the market. The plan of the market is organized around five landscaped patios, with open grounds to allow local species to grow. The railings on the central patio form planters with tropical plants. The whole area around the building is renewed with alignments of trees to constitute a biological corridor with the nearby botanical garden. The whole forms niches for biodiversity (insects, birds, butterflies, small rodents).

Land use & Transformation

Before the rebuilding of Zando (local name of the Central Market in Lingala), the area of the previous market was unsanitary, congested and dangerous. The “old” market, from the 1970s, initially built for 3,500 vendors, was never refurbished: the lack of sanitary facilities and waste management created a breeding ground for microbes and disease. The uncontrolled increase of vendors (estimated at 20,000) spread out across the whole area, blocking the streets. At night, the market was stormed by the Shegues, orphans living in the streets who committed violence and theft in order to survive. The pandemic in 2020 was an opportunity for the authorities to close the area and launch regeneration of the site.

Participatory Design

The initial brief of the client was summarised in 20 lines, listing some functions: covered market, shops, food court and bank area, a logistics area with cold stores, and a central security office. Our first mission was to define the program precisely with surfaces. We organised workshop sessions with different actors – client, representatives of the City and departments, urban authorities, representatives of the vendors, market headquarters, city firemen – to adapt, adjust, complete and explain the project. Our vision as urban planners and European architects helped to redesign the global area, in order to propose a functional and secure masterplan. We also provided more comfort and security, applying safety rules.

Community Impact and Resilience

As architects, our responsibility is to provide functional and secure infrastructure to empower the local population. This contract has been designed with Kinshasa in mind. Zando is the only place where everybody can meet, regardless of social position. Our program offers a range of different spaces: shops (S, M or L), stalls rented by the linear meter, or floor space rented by the square meter. Every Congolese market includes an informal market area to give access to the most modest traders. Furthermore, the DRC has a large number of disabled people, as a result of conflicts and illnesses: the upper floors of the market are accessible to everyone via giant slopes. Finally, bioclimatic design ensures comfort (air, shade) for all.

Financial Feasibility

Zando’s design has been adapted to fit the client’s business plan. The main feasibility concern was ensuring construction. Everything is calculated: the number and size of shops, the amount of bricks for the façades, with a search for rationality and balance. But cost of construction is nothing if not related to exploitation. Indeed, the DRC suffers a lack of money, technical capacity and knowledge for maintenance. That is why we eliminated all the unnecessary, choosing simple and mechanical products, reducing technology and finishes. This building will welcome 20,000 vendors and thousands of daily visitors: building materials are resistant, and the spaces are sized to European standards, to reduce degradation and optimise costs.

Aesthetic Qualities and Cultural Integration

Zando appears as a new modern African construction, while also an heir to the modernist Brutalist architecture of the continent. Concrete shapes follow the history of the previous market with its mushroom-shaped slabs that became an emblem of the market. The choice of this form follows function: to ensure shady spaces for all and to resist heavy loads. Associated with the concrete structure, terracotta bricks come from local architecture, colours and industry. We selected different patterns related to function (ventilation) and inspired by traditional designs (wax, tattoos). Another advantage of terracotta is the colour of the local clay which naturally fits into the landscape. Last but not least, the vegetation is local.