Building for the Africa's Urban Billion within Planetary Boundaries

Abstract

Globally, the built environment consumes half of all materials, contributes almost 40% of global greenhouse gases, and produces 30% of waste. While Africa has historically not contributed significantly to these negative environmental impacts, its projected population doubling by 2050 will make it a major player in construction. Fortunately, Africa is home to innovative designers who are actively addressing this issue. MASS has been deeply involved on the continent for nearly 15 years, focusing on healthcare, affordable housing, community resilience, and conservation. Through various projects, MASS has demonstrated how thoughtful design can minimize disruption to ecosystems by reconsidering material choices and usage. Two notable projects exemplify this approach. RICA, the Rwanda Institute for Conservation Agriculture, integrates biogenic and low-impact materials while using the construction process for training and job creation in regenerative practices. These structures, located in a seismic zone, utilize stone foundations, compressed earth brick walls, and wood roofs to reduce embodied carbon by 60%. Notably, 90% of the project's budget supported the local workforce and material supply chains within 500 miles of the site, fostering community prosperity. The new Norrsken hub, housed in the historic École Belge de Kigali, showcases adaptive reuse within a dense urban setting. MASS preserved the school's historic structure while updating it to modern standards, creating green spaces and public areas. This project sets a precedent for harmonious restoration and mixed-use development in the Central Business District, illustrating how existing architecture and ecology can coexist synergistically.