Where are the largest opportunities to decarbonize in the built environments?
Photo by Claudia Lorusso on Unsplash
In recent years, every IPCC report published reiterated the emphasis for a need to conduct deep and thorough decarbonization, citing numerous alarming evidences that document the intensity and pace at which the climate is changing due to anthropogenic forces. This changing climate is a challenge unlike any other that humanity had [caused, and] faced. To come out on top, we will need to comprehensively transform all economic sectors across the globe, by creatively adapting as fast or faster than the changing climate.
So how will we creatively adapt as fast or faster than the changing climate? One piece of the climate puzzle is decarbonization of built environments across various market segments, where many opportunities (and solutions) already exist. Where are the largest opportunities to decarbonize though? Well… it depends, so let me explain why.
Below are three distinct groups of built environments with the largest opportunity to decarbonize (from easiest to hardest):
New construction residential & commercial environments
Residential and commercial buildings is the largest market segment of built environments in the United States and across the globe by absolute number. It is also the segment with highest number of turnovers and associated remodels (i.e. resource consumption = carbon emissions) as tenants move in and out. Due to the sheer number of buildings and turnovers, residential and commercial buildings also represent the largest chunk of potential decarbonization opportunities in the built environment by absolute numbers. Just think about it. Everyone has to eat, sleep, and rest. Similarly, almost every business has one work space for employees to conduct meetings, store and use equipment, and focus on tasks. Additionally, retail stores are critical for everyone’s day-to-day business. This is especially true for groceries and other essential services such as mail, which naturally render retail locations abundant in our surroundings.
Likewise, decarbonizing all residential and commercial buildings may seem to be “the climate crisis solution”, and I agree that this will play a critical role. However, the large number of residential and commercial buildings do not explain enough to help understand the entire decarbonization story and much less so in tackling it. Decarbonization is a multifaceted process, and the largest opportunity represented by this sheer number of residential and commercial buildings is just one of them. Others facets include the nature of the built environments’ use that underlie their carbon footprint.
Residential and commercial properties generally have a set of known functions and requirements. As previously mentioned, everyone knows what people do at home: eat, sleep, and rest. Similarly, at work, people engage in meetings, store and operate equipment, and focus intensely on their tasks. Variations certainly exist, but salient deviations are extremely rare. Therefore, the consequential predictability enables standardized and optimized approaches to minimizing the use of materials (i.e. embodied carbon), energy, and water. Moreover, because most homes, offices, and stores are not used for resource-intense industrial processes that consume lots of energy and/or water, residential and commercial buildings entail less greenhouse gas emissions relative to most other market segments per square feet. Furthermore, technology alternatives appropriate for residential-commercial application to decarbonize traditionally carbon-heavy (i.e. fossil fuel) end-uses, such as water and space heaters, clothes dryers, and residential cooking, already exist at or near cost parity.
In sum, residential and commercial segment is the easiest to decarbonize and at a very large scale, but its decarbonization will not help solve more intense uses such as...
New construction laboratory & industrial environments
Laboratory and industrial environments have the largest carbon footprint of all building typologies per square feet, even though they are among the smallest in numbers worldwide. Additionally, the carbon footprint among different buildings, and even between different parts of buildings, can be wildly variable. In many ways, laboratory and industrial segment is the complete opposite of residential and commercial segment.
A part of the reason behind this variability is because laboratory and industrial facilities are highly specialized. Each facility (and even the space within) is designed to perform a specific function with associated requirements, which are often very different from one another. For instance, in the case of laboratories, researchers from the same field and/or department often study very different phenomena with equally different equipment and requirements in adjacent spaces. In the case of industrial facilities, by nature and scale of their functions, they necessarily use large and energy and/or water-intense equipment with multiple redundant systems running concurrently (i.e. consuming resources while sitting idle) for operational continuity and reliability.
The level of specificity involved in laboratory and industrial applications render standardization and optimization difficult to achieve, if not impossible. Moreover, the technology alternatives to traditionally fossil fuel-driven processes, such as industrial process heating requiring consistent 350 °F and above, are not cost-effective nor market-ready. These difficulties often discourage even the most fearless of sustainability advocates when laboratory and industrial projects roll in to their offices. The optimistic angle to think about these challenges, however, is that meaningful solutions to decarbonize laboratories and industrial environments signal even more efficient and effective decarbonization of easier-to-decarbonize environments, such as residential and commercial buildings.
Simply put, laboratory and industrial segment is among the most difficult to decarbonize, but its success will enable other building typologies to decarbonize more easily and yield larger benefits for the environment. Despite this optimism, there is yet another category that laboratory and industrial segment’s decarbonization will not solve, and that is…
Existing environments across all typologies
Here is the 3rd facet of the decarbonization process, and perhaps the most important one: time. Starting fresh from scratch is always easier than to go back and fix an old mess. Likewise, building new modernized building is easier in many ways than fixing up an outdated existing one.
During new construction projects, there are plenty of opportunities to evaluate the building’s infrastructure needs, and to update the design to reflect new requirements. Existing buildings, on the other hand, do not have that luxury. They are stuck with what they have more often than not. Want to change out ducts and plumbing for a new energy-efficient space heating equipment? One will frequently need to demolish multiple perfectly-serviceable wall partitions and ceilings to make space for the new equipment because the old equipment space was too small, and/or to the clear the space needed to drag the new equipment into the space from outside of the building. If demolishing walls is not a possibility because they are load-bearing structural members, then the equipment will have to go elsewhere that may not have been designed to take its additional weight, which then trigger code requirements necessitating the entire building’s structural system to be retrofitted with invasive seismic upgrades.
In this vein, seemingly small changes in existing buildings can and often do snowball into much larger issues. These cascading impacts contribute greatly to ballooning project costs, and add construction waste on the balance sheets. Furthermore, while new constructions have permitting as an unavoidable checkpoint (i.e. ideal enforcement point), existing buildings do not have comparably effective intervention mechanisms that allow enforcement agencies to ensure the implementation of appropriate decarbonization strategies.
Despite these challenges, existing buildings represent an overwhelming majority of all building stock available worldwide regardless of the market segment, therefore, they have the largest (and generally the most difficult) opportunities to decarbonize in the built environment. After all, buildings stick around for a long time, and their carbon footprints’ ramifications will too if left unmitigated.
There are other opportunities in the built environment to decarbonize, each with their unique concerns and uncertainties that add layers of complexity and nuance, such as greenification-led gentrification (hint: the subject of my next blog post).
At the pace in which the climate is changing, I am personally of the position that we need to explore all avenues to decarbonize everything as rapidly as possible. However, I also recognize the importance of ensuring that the mistakes made in the past—such as the inequities experienced by residents of disadvantaged communities—are avoided in the decarbonization process, through slow but important stakeholder engagement processes. To that end, what we know for certain is that the complete and cost-effective decarbonization of all buildings is necessary, to equitably distribute the economic and environmental benefits [and burdens] that will follow any environment-friendly strategy.