Eco Explainer: What are Green Building Certifications?

Unsure what those building plaques mean? Breaking down LEED, Passive House, Living Building Challenge, and other certifications.

What does it mean for a building to be “green”?

Almost 40% of greenhouse gases stem from buildings and construction, more than any other sector. Evaluating a building’s environmental impact can be tricky.

Can a building be labeled as green if it receives 50% of its power from an on-site solar array, but lacks insulation? What if it fails to conserve water in a drought-stricken area? What if it’s built entirely from reclaimed materials, but construction bulldozed an endangered species’ habitat?

Green building certifications are one way to ensure projects are designed, constructed, and operated in a sustainable way.

Green Philly sat down with Scott Kelly, Founder and Partner at Manayunk-based architecture and sustainability consulting practice Re:Vision, to demystify the world of green building certifications and explore their role in Philly’s commercial and residential landscapes.

What are green building certifications?

Green building certifications officially accredit a building as meeting a defined set of standards for environmental performance. They typically consist of hyper-specific and data-driven frameworks that outline goals related to energy efficiency, materials used, water usage, or other markers.

Because they are developed and administered by third-party organizations, these certification systems offer fair benchmarks for building projects, ensuring building users that no corner-cutting or “green-washing” occurred. In short, green building certifications enhance the credibility of projects that pursue them. Notable Green building certifications include LEED, Living Building Challenge, and Passive House.

“The landscape is filled with rating systems,” Kelly summed up. “The key thing is to help people find the right one that’s good for them.”

Caption: Photos displaying different green building projects that Re:Vision has worked on.

Overview of certifications

LEED

LEED, short for Leadership in Energy and Environmental Design, is the most commonly used green building certification.

It offers several different rating systems depending which aspect of a project is being examined; for example, LEED BD+C certifies that the design and construction of a new or renovated building meets environmental standards, LEED ID+C is concerned with the building’s interior design and construction, and LEED O+M benchmarks the impact of an existing building’s operations and maintenance.

These rating systems operate on a points system: after certain prerequisites are met, a building’s performance is scored in categories such as energy, indoor environmental quality, water efficiency, materials and resources, location and transportation, and more.

A project could earn a minimum number of points to simply be LEED certified, or it could go further and earn additional points to be silver, gold, or platinum certified.

There are almost 300 LEED-certified projects in Philadelphia including Lincoln Financial Field and the Comcast Center, along with residential, commercial, and public buildings.

Living Building Challenge

The Living Building Challenge is widely considered one of the most rigorous and highly ambitious green building certifications to undertake as performance-based. The goal of projects pursuing this certification is to design buildings that go beyond minimizing environmental harm; they have a regenerative and restorative impact on surrounding ecosystems and the climate.

For a new building to receive the highest “Living” certification offered, it must meet 20 different requirements across 7 categories referred to as “petals”: place (location), water, energy, health/happiness, materials, equity, and beauty.

“In LEED, you use energy modeling to predict how it’s going to perform. For the Living Building Challenge, what matters is your energy bill after a year of performance,” explained Kelly.

Passive House

Passive house looks at two categories very deeply: energy and indoor environmental quality, explained Kelly. Passive House-certified buildings uniquely slash energy usage by employing passive heating and cooling techniques. This means they are designed to retain or deflect warmth using naturally occurring means such as sunlight, enabling structures to meet heating and cooling needs without additional energy use.

To do this, architects utilize continuous thermal insulation, high-performance windows, specialized ventilation systems, and other techniques like strategic placement of shading, heat-trapping thermal masses, and building orientation to keep the building airtight and minimize uncontrolled heat transfer.

There are a few different organizations that offer their own versions of Passive House certification.

Other Certifications

There are countless other certifications centered around the built environment. Fitwel and WELL are both certification programs that closely examine a building’s impact on human health. Energy Enterprise’s Green Communities certification is designed specifically for the affordable housing sector.

One building can be certified to several overlapping standards: “LEED is a good base for something like Living Building Challenge. You don’t get to the aspects of the Living Building Challenge of net-zero energy without going through Passive House,” said Kelly.

Because this landscape can be so difficult to navigate, many projects opt to hire firms like Re:Vision to guide them through the process.

Why green building certifications matter

Sustainable buildings protect the occupants’ health, promoting happiness and a lesser impact. They’re also cost-effective. Kelly described one case where Re:Vision helped a client decrease their energy usage so low that after the 2008 financial crisis hit, they didn’t have to lay off any employees.

While green building certifications are a tool for accountability, they are not the sole determinant. Standards have evolved as research and technological improvements have made new innovations possible.

One common misconception is that green building certifications can only be awarded to new builds. “In a typical project, half of your environmental footprint is in the actual construction. Half of your environmental footprint is in the operations,” Kelly elaborated.

And while a certification guarantees a building project meets a defined set of goals, uncertified buildings aren’t necessarily always missing the mark on sustainability.  

Despite an uncertain political climate, there will always be market-driven justifications for projects to pursue these certifications.

And in some places, green buildings have begun to be mandated. In Philadelphia, city code dictates that all new or renovated City buildings must achieve a LEED Gold certification.

However, more can always be done. Kelly proposed an idea for Philly: mandating that every new roof be designed to accommodate future solar energy. “All you need to do is show on the structural drawings that the roof can accommodate 5 extra lbs of load for solar panels. It will make it so much more affordable,” he said.

Cover Photo: Visit Philly