As green building continues its upward trend, multiple rating systems have sprouted globally as a means of measuring and quantifying sustainable efforts. Although these systems vary in size, requirements, global influence, they share a collective commitment to minimizing harmful impacts on the environment. In early April, the USGBC announced it would begin to recognize components of the Living Building Challenge (LBC) green building rating system within its LEED program. This new collaboration signifies another strong forward march for the industry as it acknowledges a communal goal of "do less harm." The International Living Future Institute, a branch of Cascadia Green Building Council, launched the LBC in 2006 as one of the highest standards for sustainability in the built environment. Similar to LEED, the LBC program is divided into categories, each of which has certain requirements to achieve certification. However, a key difference between the two green building ratings systems is that projects pursuing the LBC are left without the option of picking-and-choosing credits to achieve a point threshold. The LBC has 20 design imperatives spread across its seven petals: site, water, energy, health, materials, social equity and beauty. Several of these ambitious goals are performance-based objectives which need to be met after 12 months of continued operation and full occupancy. The challenge aims to transform how we think about every single act of design and construction as an opportunity to positively impact the greater community of life. The LBC takes the green building notion of "do less harm" to a higher level of "do only good." Some of the project essentials are "net positives;" net positive water, net positive energy and net positive waste. These call for captured precipitation and closed loop water systems, 105% of project energy needs to be supplied by on-site renewable energy, and the elimination of waste production during all phases of the project life. These intents represent only three of the 20 Challenge imperatives. The LBC rating system puts together a tall order for certification...but not an unattainable one. A handful of structures have employed innovative technologies and designs to become Certified Living Buildings, while an even greater number have achieved the net zero energy standard. To date, over 200 projects internationally have been registered with the LBC. As the rating system continues to gain traction, we can look forward to more and more projects rising to meet the challenge. Victoria Tsamis is a sustainable engineer at Edwards & Zuck, New York, N.Y.