When the U.S. Green Building Council (USGBC) created the Leadership in Energy and Environmental Design (LEED) green building program in 2000, who could have known this idea would turn into a global movement with more than 1.5 million square feet of building space becoming LEED certified every day? The program has grown to include more than 184,000 LEED-credentialed professionals and more than 51,000 projects participating in LEED, making up 9.7 billion square feet of construction space.
LEED’s ability to affect market transformation is its continuous improvement cycle. Fueled by input from the green building community, USGBC and hundreds of volunteers have worked to develop the LEED green building program as the global understanding of building science changes, new technologies emerge, the needs of the marketplace evolve and environmental priorities shift.
The result is a technical update to the rating systems: LEED v4. This rating system offers a new global perspective, an improved user experience and a better focus on building performance. This November, USGBC will launch LEED v4 at the Greenbuild International Conference and Expo in Philadelphia.
With LEED 2009, the primary changes were foundational, such as rating system alignment, the development of LEED Online v3 and updates to the professional credentials and certification process. LEED v4 builds on these changes to improve the clarity, functionality and interconnectivity of the LEED program, while focusing on additional improvements.
New Market Sectors
The building industry now uses the LEED rating system for a wider variety of project types than before. From stadiums to convention centers, commercial offices to hospitals, each space has unique challenges when using LEED standards. LEED v4 addresses 21 different market sector adaptations—each reviewed by market leaders who either own, design or operate those buildings—to identify the needs of those markets and to address needs within revisions to LEED v4, which provides new solutions for these sectors:
- Existing schools
- Existing retail
- Data centers (new and existing)
- Warehouses and distribution centers (new and existing)
- Midrise residential
Improved Environmental Outcomes
LEED v4 emphasizes the potential for projects to positively impact their communities and the planet. USGBC developed new impact categories that determine the technical requirements of the rating system and that reposition the LEED development trajectory from encouraging buildings to “do less bad” and instead “do more good.”
With a focus on performance outcomes, LEED v4 is structured to help LEED users have a better understanding of how to manage their buildings’ performance to ensure they are reaching their full performance potential. Performance is addressed in technical changes within each credit category:
Location and Transportation
For the first time in the building and construction rating system, “Location and Transportation” is considered a separate category. The purpose is to reward projects that are within relatively dense areas, accessible to a variety of transportation options and on sites with development constraints. This category recognizes projects that allow occupants to benefit from the surrounding community infrastructure, context and amenities.
The “Sustainable Sites” category emphasizes the vital relationships among projects, ecosystems and ecosystem services. This category encourages restorative environmental solutions (on and off site) that take advantage of ecosystem services and preserve animal habitats and biodiversity.
Expanded in scope, the “Water Efficiency” category addresses total water use in LEED buildings and encourages projects to seek efficiency in water operation most heavily used by the project. Requirements for building level water metering ensure that LEED projects will be able to effectively monitor and improve their water use during operation.
Materials and Resources
The LEED v4 “Materials and Resources” section relies on a life-cycle thinking approach to building product and material selection and organizes the credits into four areas: reuse, assessment and optimization, human and ecological health and waste management. This revised credit category better defines the environmental priorities of the LEED project development process and offers organized, actionable credits while maintaining effective requirements established in previous versions of LEED.
Indoor Environmental Quality
The credits in the “Indoor Environmental Quality” category have been grouped into four areas: indoor air, light, sound and experience. The category recognizes strategies such as air testing and taking a systems approach to material selection to minimize volatile organic compounds in a space. For the first time, LEED for New Construction and LEED for Commercial Interiors include a credit for acoustical design, which can have a major impact on occupant comfort and performance.
A Global Reach
After more than 10 years in the marketplace, LEED is now used in more than 145 countries. LEED v4 will help further the mission of USGBC on a global scale. The new rating system will allow for regional and local equivalencies to typical referenced standards to give project teams greater flexibility. Project teams will also experience a greater ease of use through integration of metric units into all tools and resources.
The User Experience
USGBC has worked with more than 100 projects testing LEED v4 through the LEED v4 Beta Program to refine the program tools and resources. The result has been significant improvement to the overall LEED v4 program:
USGBC has restructured the reference guide to highlight the most useful information for project teams, which includes the following sections: behind the intent, step-by-step guidance, examples and further explanation. The improved presentation will help project teams focus on the implementation of LEED credits.
USGBC has worked to simplify paperwork so project teams can focus on achieving credits rather than documenting them. The forms have gone through more than 18 months of development and several rounds of review to ensure the documentation process does not create an unnecessary burden for project teams. Fields within forms have been minimized, and they are more focused on industry-standard documentation, which reduces the need to create documents simply for LEED certification.
USGBC has implemented three key changes to forms:
- Combined forms for prerequisites and credits. This reduces the amount of overlap and duplicative work.
- Downloadable calculators. This gives LEED users a better grasp of the equations behind the calculations.
- Less documentation needed. Industry-standard documentation often provides all the information needed to confirm credit compliance, and the USGBC has modified submittal documents to reflect that.