Stock-constrained design of pseudo-standard walls from studs off-cuts

Abstract

The AEC industry is responsible for 40% of global greenhouse gas emissions and 38% of EU waste, much of which is landfilled. The AEC waste represents an immense portion of resources that could be used instead of new materials. Many ongoing research projects have explored ways of reusing irregular components in construction, from whole steel trusses to single elements, triangulated subparts, or even irregular wood offcuts in order to mitigate the intensive recycling and deconstruction processes. However, the research has focused on general methodologies or one-off prototypes. This paper introduces a systematic approach to repurpose discarded steel and timber studs - components that make up to 10% of waste on local sites (Parigi, 2021) - into modular, steel-frame, load-bearing walls, providing a way to build new structures for the growing global demand for housing and infrastructure, while minimizing the creation of new emissions through the use of waste elements. Through a topdown and stock-constrained design approach, geometry optimization through a matching algorithm is combined with topology optimization to generate and evaluate various configurations to minimize new emissions and maximize structural efficiency. A human-scale prototype further assesses costs, architectural and structural flexibility, construction feasibility, robotic efficiency, and embodied emissions, offering a promising pathway for sustainable construction through effective waste reuse. For the available inventory, a human-scale prototype gives data on the workflow. This approach tackles the issues of existing waste stock with the growing demand for infrastructure and minimizes embodied emissions through structurally efficient resource use by pushing forward a systematic implementation of reuse in common construction practices.