Green Buildings: De-Carbonizing the Built Environment

You might be surprised: the wasteful, gigantic gas guzzler on your block might not be the oversized SUV, but the building it's parked in front of!

It's hard to get angry at buildings. They look innocent and unassuming compared to some of their more infamous climate-busting peers like coal plants, tar sands and monstrous oil refineries. While the latter are contributors, the sum total energy consumption from commercial and residential buildings worldwide, referred to as the global "built environment," contributes 40% of global carbon emissions. Yes, almost half.

This ratio holds true throughout the United States and that's a pretty big nut. But it doesn't have to be that way. So where to start?

First, there's an encouraging environment of intellect, a culture of smart policy beginning to emerge. The Biden Administration's Build Back Better initiative calls for the energy use upgrade of at least 4 million buildings and weatherizing of 2 million homes over the next 4 years.

"...the sum total energy consumption from commercial and residential buildings worldwide, referred to as the global "built environment," contributes 40% of global carbon emissions."

And the goals of Build Back Better will require engagement from federal to state and down to a local, street block level. The old adage "think globally, act locally" applies more than ever here. Given both the existential need for urgency and the inertia of national and international governmental bodies, it will ultimately be up to state and local entities, and the initiatives of private enterprise, to convert intent into action.

So, what has to happen at the state and local level?

Let's start by quantifying the problem on a global level. In order to reach the goals set by the Paris Climate Agreement, buildings will need to improve their energy intensity (or use) by 30% in the next ten years. About 70% of this energy is considered "operational carbon emissions'' -- i.e., the carbon generated by day-to-day activities occurring in an already-built structure. The vast majority of these emissions come from buildings that are over 10 years old, which comprise 95% of all building structures. This suggests that retrofitting existing buildings will need to be a key element in the initial phases of a transformative building strategy.

"In order to reach the goals set by the Paris Climate Agreement, buildings will need to improve their energy intensity (or use) by 30% in the next ten years."

But retrofitting old buildings alone won't get us there. There are limits to the extent of which these structures can be renovated, and old buildings can't be swapped out overnight. Starting immediately and over time, new buildings will need to be designed to be carbon-efficient, if not carbon neutral -- employing highly-engineered green materials, onsite renewable power generation, and natural ventilation and lighting. Given the speed and scale required to transform the current building stock and reach 2050 goals, the environmental cost of initial building construction (a.k.a. "the embedded carbon" of a building, of which accounts for 30% of building energy consumed globally) needs to be dramatically reduced. Bottom line: a lot of math has to be moved very quickly for an industry that measures time with calendars, not stopwatches. Yikes! So, we'll need to run a marathon at the speed of a 100-yard sprint, but the good news is that we actually have a running start.

I'd like to present four "points of leverage" that represent vehicles to transform broad, national policies and goals into on-the-ground mobilization. For each, I'll also specify at least one ACTION that building professionals and citizens alike can take.

1. Legislation: Residents and commercial building owners need to take advantage of knowledge and resources brought to light by city and state legislation.

At the state and local level, there are numerous laws and initiatives aimed at reducing greenhouse gases, and a number of them have been in place for quite some time. One example is New York City's Building Emissions Law, or Local Law 97 (LL97), which is the centerpiece of the city's Global Mobilization Act, passed in 2019. It covers approximately 50,000 buildings and nearly 60% of the city’s building area. The law requires 40% citywide emissions reductions by 2030 from a 2005 baseline, which would reduce carbon emissions from covered buildings by 26%.

To support this legislation, the NYC Mayor's Office of Sustainability -- alongside a team of architects, scientists, engineers, and city planners -- created the Retrofit Accelerator. This is a program that guides people managing buildings (or living in them) to lower pollution and carbon emissions. lf you go to their website, you'll see a straightforward guide, "Ways to Save Energy and Water," detailing specific actions that can be taken at the residential and commercial level -- covering areas such as heating, air conditioning, ventilation systems, lighting, water conservation, air sealing and insulation, and renewable energy. Additional good news is that these programs align with new plans at the federal level. Build Back Better calls for direct cash rebates and low-cost rebates for investments such as energy-efficient home appliances and high-efficiency windows.

ACTION: Whether you're a homeowner (59% of the covered buildings are residential), a small business owner, or a building manager, check with your state website to see if there are any equivalent programs in your area. Familiarize yourself with the investments you can make in energy efficiency technology and the services available to you.

2. Utility Programs: Utility companies need to conceive of innovative programs that not only inform building owners and residents about carbon-friendly technologies but also provide incentives for these stakeholders to invest in them.

In addition to legislation, large utility companies are offering energy efficiency programs to residents and businesses. These programs generally share three elements:

  • Resources to help identify and install technologies that lighten the load on the grid, such as LED lighting, high-efficiency boilers, air conditioners, solar heating, and renewal of on-site energy sources.
  • Monetary incentives in the form of cash rebates that scale based on energy saved by installing new energy-saving technology.
  • Systems that accurately measure energy consumption, oftentimes through the combination of "smart metering" (small measuring sensors that measure energy usage at the device level, and energy monitoring software that helps users pinpoint efficiencies across all building components).

Pacific Gas and Electric (PG&E) has a long history of energy efficiency programs. Their programs have evolved to focus on specific industries, such as the Health Energy Efficiency Program (HEEP) that targets medical facilities. PG&E works in conjunction with an energy efficiency specialist firm, Willdan Energy Solutions, to offer energy audits, engineering analysis, and implementation management. Incentive payments are based on both energy usage and reduction of peak demand -- as metered and measured by an energy monitoring system. For example, installing a high-efficiency refrigeration unit would not only yield lower daily energy costs -- but would entitle the building owner to a rebate of 12 cents per kilowatt-hour) and $150 dollars for every kW shaved off of peak demand.

ACTION: Learn about what utility programs are in place or are being planned in your state, and put the associated recommendations into action in your own home or business. It's as simple as going to your utility provider's website, which generally provides both energy savings ideas and resources to equipment providers and installers.

3. Industry Collaboration: A broad range of building professionals in the public and private sectors need to form partnerships aimed at taking a multi-disciplinary approach to the climate challenge.

A number of non-profit organizations have been founded to facilitate collaboration among public and private enterprises with the goal of reducing the built environment's carbon footprint. The most widely known is the United States Green Building Council (USBC), a consortium of architects, engineers, developers, builders, product manufacturers, and government agencies. Its centerpiece initiative is the Leadership in Energy and Environmental Design (LEED) program that awards professional credentials to specific buildings through a points system that covers nine broad green building measures.

Compared to the aforementioned energy efficiency measures, the LEED points system takes a much more broad and impactful approach. It looks at buildings in a holistic manner -- measuring not only the carbon output of the building itself but other tangential impacts as well:

  • Transportation to and from the building for both its builders and its ultimate occupants.
  • Extraction, processing, and disposal of building materials.
  • Indoor environmental quality and comfort.
  • Use of renewables -- both on and offsite.

ACTION: Buy energy-efficient appliances. The Environmental Protection Agency (EPA) formed the EnergySTAR program to certify a broad range of appliances -- including refrigerators, washing machines, and other household items. These items often significantly exceed the minimum government standards for energy use.

4. New Design Practices: It's not good enough to improve what we've already built. We need to invent fundamentally new ways of creating carbon-friendly buildings.

Much of climate action associated with buildings has been focused on retrofitting existing structures. But there are limits to the efficiencies that can be extracted from buildings already in place. In order to meet the aggressive carbon reduction goals cited above, it will be essential for innovative design practices to be put in place for new construction. One such practice is "building fabrication." Recall that 30% of carbon emitted from buildings is "embedded carbon" -- in other words, generated from the initial construction process.

Consider the traditional "stick-built" process. Material is inefficiently transported from multiple locations to the building site where wasteful, carbon-intensive processes using heavy equipment and cutting equipment are employed in an outdoor environment that spew carbon into the atmosphere. Waste from the processes is then transported from the site for disposal. By contrast, building fabrication uses efficient, mass manufacturing principles to pre-construct building components in a controlled environment, and these components are simply assembled at the business site with minimal carbon impact. Employing this technique provides a faster, cleaner, more cost-effective way of meeting the Build Back Better mandate of constructing 1.5 million sustainable homes and housing units.

ACTION: Buy a prefabricated house! They’re carbon-friendly and efficient, yet modern, airy, open, and aesthetically pleasing. Blu Homes offers a variety of prefab homes at surprisingly competitive prices -- with a variety of building styles to choose from. Check out their really cool gallery.

When it comes to the built environment's consumption of energy -- it'll take more than federal government policies and goals to tame this beast. Ground-level actions spurred by legislators, utilities, public/private partnerships, and new building innovators -- as well as an engaged citizenry -- will be required to make a carbon-neutral, built environment a reality.