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.