Zero-energy green building in a data-enlightened era

Inside SFO’s ambitious mission to achieve net-zero energy.

Last year, San Francisco International Airport (SFO) set a moonshot goal to become the very first airport in the world to achieve net-zero energy, net-zero waste, and carbon neutrality by 2021.

As the gateway to the technology center of the world, the SFO team — where I’ve served as Sustainability Director for the past two years — is embracing the opportunity to not only decarbonize our intermodal transportation and on-site energy sources, but to share our learnings and serve as a model to drive forward the future of green resilient buildings everywhere.

Achieving this herculean task required a pivot from prescriptive-based to performance-optimized building designs. We went from meeting predefined targets with few incentives for innovation to a conversation in which all stakeholders could discuss and discover critical steps to achieve our new bold objectives.

Our environmental consciousness is not necessarily new — San Francisco International Airport has prioritized sustainability for more than two decades. Since the 1990’s, we’ve curtailed emissions by nearly 33-percent amidst a 72-percent growth in passengers and 83-percent growth in building footprint. That’s a 60-percent cut in emissions on a per passenger basis.


In the past three years, we’ve again cut water use by 52-percent and energy use by 25-percent. All these efforts lead to costs savings — our operational conservation programs save an estimated $650,000 in annual utility costs.

Harnessing New Tech to Become a LEED Leader

In 2008, the San Francisco Environment Code designated LEED Gold as the baseline new construction standard for all municipal facilities, which has led to nearly 30 LEED Gold registered and/or certified in-progress projects.

SFO’s journey to “build” its environmental legacy comes embedded in our municipal genetic code of being located within the environmentally bold City and County of San Francisco. This drives our pursuit and success in achieving the industry’s first airport LEED Master Site.

LEED is an internationally-recognized green building certification program that provides building owners with a framework for implementing practical and measurable green building design, construction, operations and maintenance solutions. LEED promotes a “whole building” approach by encouraging performance in several key areas such as water efficiency, resource conservation, and energy efficiency. SFO achieved these steps, and more, to receive the LEED Gold designation for the Terminal 2 renovation in 2011. It was the first in the industry to accomplish this for a terminal.

The T2 LEED certification manifested as special hydration stations, an innovative displacement ventilation system that uses filtered air to improve indoor air quality, and a dual plumbing system that allows reclaimed water from SFO’s water treatment facility for reuse. It also includes energy efficient lighting and sustainable building materials among many others. Travelers can actually tour these features in T2 here.

A Global Movement

Energy became the main driver behind design and performance in 2017 when SFO stepped beyond these LEED requirements and reached higher with a “BHAG,” or “Big Hairy Audacious Goal” to achieve zero net energy, carbon neutrality and zero waste by 2021.

It transformed the way we design, discuss, and even value engineer projects. Prior to our goal, electrical metering was used primarily as a tool to bill customers and not leveraged as a system to monitor energy across the campus.

While certifications and prescriptive rating systems have certainly been simplified and streamlined for improved performance, we’ve found they often only nibble around the core of the big outcomes that airport owners and operators seek.

To avoid this, SFO initiated a progressive design-build, integrated project delivery, and team-based approach to ensure that no interest, objective, system, or discipline was left behind. We rooted this in a performance approach to offer maximum design flexibility, allow for trade-offs between building features and systems, and optimize for project results.

For example, designing terminals to maximize daylight is important for the health and happiness of our passengers as well as reducing lighting energy consumption. However, larger windows have the unfortunate consequence of increasing HVAC loads inside a space. Our designers sought to resolve this issue by designing some of our windows to be electrochromic, which dynamically darkens throughout the day. These windows automatically respond to allow for the optimal amount of daylight into a space, while simultaneously reducing HVAC loads.

Submeters — the ability to monitor the consumption output of individual equipment within a building — also became the standard to help source energy hogs and equipment anomalies. We were able to uncover energy models that inaccurately predict plug loads, and build behavioral and occupant characteristics that can mean the difference between operating a zero net energy building or not.

Harvesting this deep data also guides operators towards energy-efficient facility investments for existing building upgrades — often forgotten in the landscape of big capital projects — and informs future design considerations based on climatic conditions, occupancy schedules, and common end-users.

It is only now, in a data-enlightened era, that achieving zero is seriously within reach.

One of the strongest advantages of setting a goal like Net Zero Energy or Carbon Neutrality is that, once defined, it is easy to quantify and validate as a metric. This has transformed us into a data-driven organization that can monitor its sustainability successes.

Through the development of tools such as campus-level energy dashboards and dynamic utility maps — emboldened and fed by the data — as well as new IoT building operating systems, we can perpetually communicate the progress towards our goals and identify which initiatives are on track and which need support.

Data is what drives forward our campus’ sustainability.

Going Beyond LEED as Leaders in the Green Buildings Movement

Although a leader, SFO is still far from alone in its journey towards greener operations.

There are more than 400 LEED airport projects around the world. It started with independent industrial-like campuses looking to lighten their heavy energy loads and environmental impact mitigation. New technology helped transform these into interconnected intermodal transportation hubs that double as LEED power-users and expert practitioners of sustainability rating systems.

For example, passengers commuting into Denver International Airport by light rail are greeted with 10 megawatts of solar energy — the equivalent to 2,500 typical Denver homes — while San Diego International Airport achieved the world’s first LEED Platinum certification for a commercial airport terminal.

These two airports, among dozens of others, are aiming higher than a certification. They’re looking beyond the performance of single building to create integrated holistic systems that save energy and expenses at every level. This comprehensive approach is what defines green airports, and green buildings, of the future.

SFO and Denver International Airport recently teamed up to submit a call to the industry via the National Academies of Sciences’ Airport Cooperative Research Project’s Idea Hub to provide achievable standardized performance targets for our sector.

If selected, this research would develop energy, water, waste, carbon and GHG for several airport-specific facility use-types that are measurable and achievable in a variety of climates, geographic locations, and source utility carbon intensity.

It would also address this “hole” in airports’ evaluations thus achieving whole building performance that would enable our industry to improve efficiency, decrease operating costs, and maximize environmental outcomes across our energy-intensive process-heavy campuses.

Industry-wide, building-specific performance targets can serve to inch airports closer to substantive and quantified results, but our pursuit of these sustainability and resilient building attributes has no real finish line.

Are airports ready for climate merit-based pay or rating-systems checklist-free design?

Not yet and possibly not ever — particularly the latter if it remains a code requirement — but we are an industry eager to to transform. We transform our facilities, our fleets, and our amenities to surprise and delight passengers.

When your scope is a global passenger base — and there are almost 44,000 airports worldwide — you have the opportunity, and now an emerging performance-focused toolkit, to address not just issues that impact our local environment but the hometown airports and local environments of every passenger we serve in every corner of our planet.


We are entering a new era of environmental innovation that is driving better alignment between technology and environmental goals — and results.