Reshaping How We Live & Move: How Tall Urban Towers & Suburban Communities Can Realize 1.5°C Ambitions

Life cycle assessment (LCA) and energy models are fantastic tools used to influence key building design decisions. However, these models almost never look up far enough to consider their surroundings.

Built environments are created by distinct combinations of buildings and infrastructure. Yet, our decarbonization solutions often focus on one and fail to consider the other as part of a living system.

Architecture 2030 estimates that transportation and the built environment combined are responsible for about two-thirds of global emissions. If these emissions could be tackled and reduced holistically, the ambitions of the 2015 Paris Agreement to limit global warming to 1.5 degrees Celsius may move closer to reality.

After months of research, the Introba and TYLin City Solutions teams have identified how to connect the dots between carbon emissions accounting methods for buildings, urban infrastructure, and transportation. We can now enable our clients to begin quantifying the whole-life carbon emissions of entire built environments. We are sharing our results to spur industry partners on.

Listen to Impact Fund author Jeremy Field talk more about this work:

To discover the most effective actions that must be taken at scale to decarbonize new construction around the world, we looked at the hypothetical carbon story from net zero versions of two globally recognized forms of built environment that could house 600 people:

• A tall, urban tower

• A suburban community

We selected these two settings because they are regularly criticized as unsustainable and familiar to many as the backdrops of American TV shows and movies. This also influenced us to primarily draw on North American sources for key details like the size of a typical home and annual daily travel patterns.

We found:

• Current definitions of Zero-Emissions buildings won't create Zero-Emissions built environments: for both urban and Suburban forms, total lifetime carbon emissions are projected to exceed 44 million kilograms of carbon (>1900 kgCO2e per m2 of floor area)—even if newly built homes align with Part 1 of the USA's "National Definition of a Zero-Emissions Building6."

• In both the Urban and Suburban forms, 55-60% of emissions released before 2030 will be from the upfront embodied carbon of the materials needed to build our structures and enclosures.

• Only a few years after that, we project cumulative user transportation impacts that will overtake the upfront burst of embodied impacts. By 2084, user transportation will account for 66% (nearly two-thirds) of total lifetime carbon emissions.

• Suburban settings appear to be the highest-emission form of built environment—but only slightly (just over 15%). Longer travel distances and user preferences in transportation modes primarily drive this.

What does this mean?

• Governments and the AEC industry must deprioritize the expansion of automobile-centric infrastructure — most critically, parking — even in light of vehicle electrification trends and redirect that funding and design effort in incentivizing shared, sustainable transportation measures and procuring lower embodied carbon materials.

• Organizations that deploy capital for urban development purposes must analyze carbon at the scale of the built environment to identify their lowest carbon financing opportunities.

This work is part of Introba's Impact Fund initiative for creating a positive global impact on the built environment. Running on an annual basis, Impact Fund specifically supports thought leadership and transformational initiatives around sustainability and digital innovation and encourages collaboration with external partners. The aim of this work is to share our findings and insights with the whole industry to create collective knowledge and action. 

Read the report here.