There are six applications of four strategies that we can apply to a new or existing building to achieve net-zero carbon. When combined with a lens toward Total Cost of Ownership, they can provide a cost-effective roadmap for building owners. 

1. Avoidance
   1. Operational Carbon avoidance. 
   2. Embodied Carbon avoidance.
2. Reduction
   1. Carbon reduction with Systems optimization (smart building tech).
   2. Carbon reduction through clean energy mix.
3. Carbon offset through Renewables.
4. Carbon absorption through green infrastructure or materials.

These first two strategies fall under the category of what I call Carbon Avoidance, and I’ve written about these approaches before. Moreover, Prajakta Thipsay, LEED GA, includes them in her excellent overview of the DRAW design process. These avoidance strategies necessitate being radically resourceful as economically feasible while designing the building, requiring the study of operational carbon (due to utility impacts) and embodied carbon (the environmental impacts from mining and materials production). 

DRAW has targeted operational carbon for the past fifteen years, designing the building envelope to reduce loads and engineering the building systems to be highly efficient, utilizing PlanIT Impact for energy modeling and cost analysis. Comparing the resulting lower EUI (energy use intensity) to industry baselines helps us measure the amount of carbon we avoided using. 

More effort has been made in the last several years on the latter strategy, studying embodied carbon. EC3 and Tally are two resources we use to help analyze the various impacts of different materials to avoid carbon impact.  

Operational carbon makes up a varying load over time compared to embodied carbon, which is all upfront during construction. The total amount of carbon and the ratio between operational and embodied is dependent on the building type. Residential homes can have roughly equal operational vs. embodied tons of carbon over time, in contrast to a manufacturing facility that might utilize more than twenty times the amount of operational carbon than embodied carbon over its building lifetime.  

 I recently attended a Coalition for Smarter Buildings meeting in Washington DC, where a group of seasoned professionals in building automation and IoT technology, among others, met to discuss how to accelerate the adoption of smart building best practices. It’s clear that when integrated with existing or new construction to optimize operational building performance, smart building technology is critical to the overall mix of strategies to achieve Net-Zero. Per the six strategies toward net-zero, it is third and falls under the carbon reduction category.  

Smart building technology can significantly reduce a structure’s use of resources, ranging from 5-45% depending on the type and age of the structure. Historically, buildings have been designed as dumb boxes that we have little insight into, even though they are one of our most significant contributors to climate change (40%).  

IoT devices can provide key data on real-time energy and water use, helping to minimize wasteful plug loads, plumbing leaks, and irrigation patterns, to name a few. According to a McKinsey report, energy waste is estimated at $179 billion annually in the US. We can’t afford to continue ignoring this problem when faced with enormous challenges like climate change. Intelligent approaches to managing our buildings are imperative.  

Clean energy is another crucial tool in the battle against climate change and is, of course, at the utility-scale. Many regions offer alternative energy purchase agreements, where customers can buy “greener” power or “green carbon offsets.” The building location’s mix of available energy is key to its overall carbon impact. Regions that utilize hydropower have less work to reduce and avoid their operational carbon impact but will still need to focus on embodied carbon to achieve net-zero carbon goals. Even though renewable energy sources help reduce a building’s carbon impact, efficiency is still important to not further strain utilities. 

The recent blocking of the Reconciliation Bill’s Clean Energy components in the Senate is a significant step backward in the mission to accelerate nationwide clean energy. This setback puts more pressure on on-site level renewables, avoidance, and reduction strategies to achieve net-zero.  

The final piece is Carbon Absorption. Our friends at ClimatePositiveDesign.org have developed a tool that demonstrates how carbon can be eliminated through green infrastructure in the landscape or building. Plants are a beautiful and comparatively low-cost way to balance unavoidable embodied and operational carbon impacts. We are just starting to delve into this strategy and are very excited about its potential in many tangible, quantifiable ways.  

How these strategies are employed will vary from project to project, depending on the constraints and opportunities to be found. Just as a LEED charrette should be done at the earliest stage of a project, an analysis of the potential net-zero approach can also be analyzed to help an owner determine a path toward net-zero carbon.