It should be evident in this time that the world faces a global climate crisis and there is a need to reduce global emissions to reverse its effects. What may not be as evident to some is the significant role that the architectural, engineering, and construction (AEC) professionals play in this situation.  The built environment is responsible for 42% of the annual global CO2 emissions. While the AEC professions are actively addressing the emissions associated with the operation of buildings (27.3%), embodied emissions have only recently been receiving attention (7%). These emissions are produced through the sourcing, production, transportation, construction, demolition,  and disposal of building products and materials. Unlike operational emissions, embodied emissions are fixed at construction, emphasizing the need for a strategic approach to achieve zero-carbon design solutions.

Due to these major impacts on global emissions, there is a significant need to develop a process and dependable strategy to undergo zero-carbon design solutions. Many pieces of this puzzle are scattered throughout established green, sustainable, high performance, and ecological design practices in the construction of the built environment today. It is the connection, rigor, and time that is hindering the progress towards this goal.

Through systematic research in advanced environmental design strategies and principles, this thesis explores pathways to zero carbon design through urban infill and adaptive re-use of buildings. This thesis contends that the principles supporting urban infill and adaptive re-use will be crucial to combating the climate crisis. These strategies are at the crossroads of numerous environmental design solutions including the limitation of urban sprawl, utilizing existing materials, land preservation, and reducing transportation emissions. Beyond environmental benefits, these strategies address social issues by revitalizing urban identity and creating spaces for essential typologies.

Focusing on a previously developed plot of land inset between two existing 1910s skyscrapers in downtown Chicago that are being threatened with demolition, this project looks at how existing structures can not only be renovated but upcycled through the infill and connection of the middle plot. Fixed on the process of how to achieve a zero-carbon design, each design decision from project scale to building systems and envelope undergoes comprehensive analysis considering environmental impacts at every stage of the building's life cycle. Strategies are evaluated by efficiency, global warming potential, geographical sourcing, and any other factors that affect the environmental impact of design decisions. These evaluations are completed using a multitude of tools including Environmental Product Declarations (EPDs), schematic level whole building life cycle analysis (WBLCA), and design development WBLCA.

This thesis argues that only through this intense and thorough analysis of a project at this scale and material diversity can a true zero carbon design solution be achieved. Consequently, the result of this project is the foundation of a design process that can be used, improved, and built upon in the future. The emphasis lies in creating a framework that not only achieves immediate environmental design goals but also evolves to meet future challenges in achieving a zero-carbon built environment.