You can’t make green choices if you don’t know what they are—and you can’t sell those decisions to clients if you don’t know why you’re making them.

“Education is the most important entry point to green practices,” says Alex Wilson, the founder of BuildingGreen, a resource on sustainable architecture and design. While there are hundreds of helpful courses, seminars and conferences, any of which can jumpstart an understanding of green design, there are also more official routes you can take. We break down three of the most widely accepted green design certifications.

Leadership in Energy and Environmental Design (LEED)

• What it is: An offshoot of the U.S. Green Building Council (USGBC), LEED is undoubtedly the most well known indicator of green design. While one portion of this certification applies to buildings themselves, it also offers certifications for designers, including specialty programs on interior design and creating LEED homes. The bulk of these certifications are targeted for commercial spaces, but the principles they impart, like how to produce less waste or use healthier materials, can be applied in residential settings as well.
• How to get involved: Professionals seeking certification all start with the LEED Green Associate exam, a two-hour test with 100 multiple-choice questions. (The USGBC offers study materials and courses as test prep.) In order to maintain their credentials, Green Associates must earn 15 hours of continuing education within two years of passing the test. Designers interested in pursuing a specialty certification, like Interior Design + Construction or the Homes designation, can either take a combined exam or take the specialty-only exam at a later time.

Passive House Institute U.S. (PHIUS)

• What it is: Passive House is a rigorous energy standard that can be applied to all types of buildings. Elements like balanced ventilation, an airtight building envelope, double-paned windows and super-insulation work together to reduce the energy needed to heat and cool, resulting in structures with extremely low carbon footprints.
• How to get involved: Like LEED, PHIUS offers certification for both projects and individuals. The PHIUS certification involves three phases: an online course followed by a five-day in-person class ending in a three-hour exam.

Living Building Challenge (LBC)

• What it is: The Living Building Challenge is perhaps the most intense standard of green building. Run by the International Living Future Institute (ILFI), the LBC requires that buildings produce more energy and water than they use (also called “net positive”)—and to be certified, the efficiency must be proven.
• How to get involved: While ILFI currently offers certifications only for completed buildings, not professionals, the organization has created two free resources for the building and design industries: the Red List, an alphabetical compilation of the worst chemicals used in materials that are prevalent in the building industry; and a database called Declare, something of a nutrition label for products, which details where and how the product is made, what it contains and what happens to it at the “end of its life,” meaning whether or not it can be recycled.

"Becoming familiar with these certifications and how they work, what they provide and what they don’t cover is key," Wilson says. It can be a challenge to know where to begin in the realm of sustainable design. But the first step is clear: educate yourself.