A New Chapter for ILFI’s Building Programs

In the ever-evolving landscape of sustainable building standards, ILFI has consistently been at the “tip of the spear,” defining a vision for the future, pushing the boundaries of what’s possible, and challenging practitioners of the built environment to reach new heights of performance and impact. Recognizing the clear role that buildings play in creating and exacerbating climate change and the need for even bolder action to mitigate the negative impacts, ILFI has unveiled significant updates across our three building programs: Living Building Challenge® 4.1 (LBC), Zero Carbon CertificationTM 1.1 (ZC), and Zero Energy CertificationTM 1.1 (ZE). These updates represent a critical next step in the evolution of ILFI’s standards to drive market transformation and create a Living Future, with a specific focus on aligning our energy and carbon program requirements across all three programs while moving toward science-based metrics and advancing industry-aligned best practices.

These updates are more than just an interim step; they are a strategic move to position ILFI’s building standards for a more comprehensive update that ILFI is now embarking on. This integrated approach to all three programs tees up a cohesive framework that enables project teams to understand the requirements of each program more clearly and achieve multiple certifications seamlessly, fostering synergies and driving innovation. By aligning energy and carbon requirements across ILFI’s suite of programs—LBC, ZE, and ZC—we are setting the stage for a future where buildings are key to the solution to climate change, not contributors to the problem.

The Imperative of Alignment

The magnitude of the problems we face is immense, and the need for collective action has never been greater. ILFI is leading the way nationally and internationally in aligning its standards and pushing for the highest level of achievement.

Beyond ILFI’s program alignments, we are making strides industry-wide to foster alignment in energy and embodied carbon accounting methodologies. ILFI’s collaboration and leadership with the ECHO Project, the White House’s National Definition for a Zero Emissions Building, and involvement with Buildings Breakthrough (co-led by the UNEP-hosted Global Alliance for Buildings and Construction (GlobalABC) and others) underscores this commitment to aligned carbon accounting. This collective effort signals a paradigm shift towards a future where relationships and knowledge-sharing can build a movement strong enough to catalyze the transformation our industry needs to meet its share of the Paris Climate Commitment to limit global warming to 1.5°C. 

As we work towards industry alignment, the International Living Future Institute (ILFI) remains committed to leading the way. As our programs evolve, we continue to push the boundaries of what’s possible and achievable in the building industry—to define What Good Looks Like. These program updates are the first steps toward implementation, with more to come! 

What’s New in LBC 4.1, ZE 1.1, and ZC 1.1

With these program updates, ILFI has preserved the tenets of our certification programs, which operate as a philosophy first, an advocacy tool second, and a certification program third. These updates reinforce and advance the highest standards of regenerative building, marking a pivotal moment in aligning and strengthening energy and carbon requirements within ILFI and the broader industry.

The updates to LBC 4.1, ZC 1.1, and ZE 1.1 are a culmination of ILFI research and development with our Technical Advisory Groups (TAGs) and feedback from our incredible ILFI Staff, trail-blazing project teams, auditors, Board of Directors, Living Future Europe, Living Future Institute Australia, partner organizations, and so many others. Thank you to all who contributed!

Although this round of program evolution specifically focuses on ILFI’s energy and carbon requirements, critical updates were made to other Petals and Imperatives in LBC 4.1. For details beyond the major updates included here, please visit our Resources page to access the Program Change Guides. You can also learn more about ILFI’s Building Certification Process here

Core as an LBC Certification Pathway

With this update, ILFI will no longer operate a separate Core Green Building Certification® program and instead solidifies Core’s place as the baseline for what good looks like across the seven Petals of the Living Building Challenge. As such, projects pursuing LBC 4.1 can achieve Core, Petal, or Living Certification under the Living Building Challenge. Requirements for certification remain the same:

  • Core Certification requires the achievement of all 10 Core Imperatives;
  • To earn Petal Certification, projects must achieve one of the Water, Energy, or Material Petals in addition to the Core Imperatives; and 
  • Living Certification requires the achievement of 20 Imperatives within all seven Petals.

Comprehensive, Accessible Program Manuals

The Standard and Handbook for each of the three building programs have been reorganized into one comprehensive Program Manual. This change brings cohesiveness to each program’s broad goals and specific requirements, providing clarity and a singular resource to project teams. Additionally, all Program Manuals are publicly available at no cost, removing them from behind the ILFI Membership paywall.

Efficiency Based on ASHRAE 90.1-2019

One of the standout updates is the integration of energy efficiency standards based on ASHRAE 90.1-2019. This shift aligns ILFI’s requirements with industry best practices while also requiring projects to go beyond the targets set by the industry, ensuring that projects certified under LBC 4.1 and ZC 1.1 are at the forefront of energy performance. For example, new Buildings must achieve a 20% improvement beyond the energy consumption levels required by ASHRAE Standard 90.1-2019 or later (demonstrating compliance under Appendix G) or IECC 2021 or later. 

Updates to Potable Water Requirements

All LBC 4.1 projects must now develop and adhere to a comprehensive water budget that includes reducing interior fixture flow rates by 25% relative to the EPAct 2005 standard, utilizing best-in-class water-consuming equipment and appliances, and implementing a leak detection system. These changes simplify the potable water baselines and conservation targets while retaining an emphasis on performance.

Science-Based Carbon Cap

In a significant step towards aligning with the 1.5-degree Celsius target set by the Paris Agreement, ILFI has introduced a science-based carbon threshold to LBC 4.1 and ZC 1.1 that serves as an interim target until the industry is aligned on budget-based whole life carbon thresholds that factor in allocations based on project density and type, building element, and location. This stringent target challenges project teams to rethink their carbon emissions, pushing for designs that are a positive force in the face of urgent and escalating climate impacts. 

Combustion Updates + Retired Exceptions

In a significant move reflecting the industry’s progress and the availability of viable alternatives, ILFI has retired exception EC-003 Combustion in Commercial Kitchens across all three programs, which previously allowed for combustion-based equipment in commercial kitchens where electricity-based equipment was insufficient. With advancements in technology and increased awareness of sustainable practices, solutions are now readily available to meet the cooking needs of commercial kitchens without relying on combustion-based equipment. The retirement of this exception underscores ILFI’s commitment to pushing the industry towards fully sustainable and electric-based solutions, reducing carbon emissions as swiftly as possible.

Fugitive Emissions

To begin to address and assess the critical issue of fugitive refrigerant emissions, all LBC 4.1 and ZC 1.1 projects must now have a maintenance plan in place to monitor and reduce fugitive refrigerant emissions from sources such as refrigeration, air conditioning, and fire suppression systems. Furthermore, a designated team member is required to join industry efforts by committing to reduce both embodied and operational carbon within the MEP industry. This requirement represents an important first step toward project teams understanding and tracking where there is opportunity to minimize impacts and then work toward reducing the significant climate impact associated with refrigerants and MEP systems.

Additional Updates:

  • Requirement for 20% reduction in embodied carbon now applies to ZC and includes exterior materials (LBC 4.1, ZC 1.1)
  • Embodied carbon calculation scope now includes additional specificity for site activities (A5a) and material waste (A5w) (LBC 4.1, ZC 1.1)
  • Scope of carbon offset now includes primary materials, exterior materials, and interior materials (LBC 4.1, ZC 1.1)
  • Amended biogenic carbon reporting and calculation requirements to include that any product claim of sequestration must be based on Product Category Rules (PCRs) in accordance with ISO 14025 and ISO 21930 (LBC 4.1, ZC 1.1)
  • Tables indicating embodied carbon scope categories are now more closely aligned with those used by LCA tools and practitioners (OmniClass™ Table 21) along with updated content for Approved LCA Tools (LBC 4.1, ZC 1.1)
  • And more!

ILFI envisions a future where buildings are a crucial part of the solution to climate change, the pathways to mitigation are more clearly laid, and industry and community leaders are working together to accelerate change. LBC 4.1, ZE 1.1, and ZC 1.1 represent a commitment to transformative and collective action, and future updates to the LBC, ZE, and ZC programs will drive even more transformation. If you’d like to contribute your thoughts toward this future visioning, please participate in our survey: Visions for LBC 5.0.

Together, let’s build a future where every building is a living building, contributing to a sustainable, equitable, and resilient world for all.


If you’d like to contribute your thoughts toward this future visioning, please participate in our survey:

Written By

Jessica Bristow

Jessica is the Director of the Living Building Challenge team, nested within the Programs + Innovation group at ILFI. In her role, she is responsible for directing the evolution, development, and maintenance of ILFI’s building programs which currently include: Living Building Challenge (LBC), Core Green Building (Core), Zero Energy (ZE), and Zero Carbon (ZC). Jessica has worked as an architect in the private and public sectors of New York City in architecture, construction, sustainability, and high-performance design. She deeply believes in the importance of healthy and ecologically restorative buildings and is excited to see and help the industry grow toward a more equitable and living future.