e-News #92: Evolution of LEED v4

March 13, 2014
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Evolution of LEED

The U.S. Green Building Council unveiled the latest version of its Leadership in Energy and Environmental Design (LEED®) Rating System during last November’s Greenbuild Conference and Expo. LEED v4 places increased emphasis on building performance and sets the bar higher for manufacturers of building materials, encouraging them to reduce environmental impacts and health hazards associated with material ingredients. Rating systems have been adapted for twenty-one additional market sectors that formerly faced barriers to LEED certification, including data centers, warehouses & distribution centers, and hospitality. Since the LEED v1 pilot program launched in 1998, LEED has been transitioning from a rating system that encourages the design and construction of buildings that ‘do no harm’ to a system that aids in the construction of buildings that provide significant environmental benefit. LEED v4 is perhaps the greatest leap in that direction. The newest version of LEED continues to transform the marketplace, but it dives deeper into more focused sustainability issues than previous versions.

New Concepts in LEED v4

What are IDP, BUG, LCA, EPD, and HPD? If these acronyms are not in your LEED lexicon, they soon will be as they introduce concepts that play a role in LEED credit achievement.

“The [integrated design process] relies upon a multi-disciplinary and collaborative team whose members make decisions together based on a shared vision and a holistic understanding of the project. It follows the design through the entire project life, from pre-design through occupancy and into operation.”

- Roadmap for the Integrated Design Process

Integrative Design Process (IDP) 

A new credit category for Integrative Design Process has been added in LEED v4. Various definitions of what defines an Integrative Design Process have been used in the industry. Although many project teams claim to use this process, there are distinct, identifiable characteristics associated with achievement of sustainability goals. According to ASHRAE 189.1 (2011), the integrated design process is “a design process utilizing early collaboration amongst representatives of each stakeholder and participating consultant on the project.” The benefits of early collaboration among all stakeholders is an increase in the likelihood of improved performance and other sustainability goals being met, as well as a reduction in potentially expensive design changes later in construction. Project teams can identify synergies among building systems early on to uncover opportunities that might be missed in a more traditional design process. For LEED, early analysis must take place before completion of the Schematic Design phase and pertains specifically to energy and water-related systems. In order to comply with LEED credit requirements, project teams must document how this analysis informed the Owner’s Project Requirements (OPR) and Basis of Design (BOD).

Backlight, Uplight, and Glare (BUG)

The Illuminating Engineering Society’s EDS Model Lighting Ordinance includes recommended light levels to enhance lighting design and provide safety at night. The BUG rating for lighting, taken from this ordinance, classifies luminaires in terms of backlight (B), uplight (U), and glare (G). This approach is becoming increasingly popular as a way to compare and select outdoor lighting appropriate for reducing light pollution. LEED v4 adds the BUG model to the Sustainable Sites Credit 8: Light Pollution Reduction as a prescriptive compliance path for meeting light trespass requirements.

Credit requirements state that luminaires must not exceed maximum uplight ratings, and maximum backlight and glare ratings must not be exceeded, based on mounting
location and distance from the lighting boundary. Project teams pursuing the BUG method for this credit will need to look to product manufacturers for data as BUG values are typically published by the manufacturers.

Life-Cycle Assessment (LCA)

The ISO 14040 Standard defines Life-Cycle Assessment (LCA) as “a compilation and evaluation of the inputs and outputs and the potential environmental impacts of a product system throughout its lifecycle.” LCAs allow for a comparison of different products by examining impacts of a product from raw material extraction, transportation, manufacturing, use, maintenance, through its end-of-life. The Materials and Resources category in LEED v4 uses the life-cycle approach as a framework for all  rerequisites and credits. Project teams can be awarded points for performing whole building life-cycle assessments and demonstrating environmental impact reductions. Material selection credits also will be based on life-cycle assessment studies, comparing the environmental and health impacts of materials in a given industry or product category.

Environmental Product Declaration (EPD)

Now standard practice in Europe, the concept of Environmental Product Declarations is new in LEED v4. An EPD is a standardized, internationally recognized tool for providing information about a product’s environmental impacts. EPDs have been compared to food Nutrition Facts labels and include lists of ingredients and information about how a product is manufactured, delivered, and installed, as well as environmental impacts of anticipated maintenance throughout the life of the product. EPDs are written summaries of an LCA (typically completed by an independent LCA professional) and are written in a way that provides ease of understanding and facilitates comparisons among materials in a product category.

Health Product Declaration (HPD)

Where EPDs are focused on disclosing the environmental degradation potential of products, Health Product Declarations focus on a product’s potential impact on human health. HPDs provide a list of all chemical ingredients in a product and demonstrate any known health hazards associated with the chemical make-up. HPDs can be self-declared or verified by a third party. By creating a credit for disclosure of material ingredients, USGBC is encouraging project teams to understand the ingredients in products and to avoid specifying products with hazardous materials. For a product to qualify for LEED, the HPD must include all ingredients down to at least 1,000 parts per million (0.1 percent) and fully disclose any health hazards associated with these ingredients.

Improved Energy and Water Efficiency

Electric Meters
Figure 1. Installation of whole-building energy meters is required under LEED v4’s Energy and Atmosphere: Building-Level Energy Metering Prerequisite 3.
Image: bigstockphoto.com

With a focus on overall building performance, LEED v4 places increased emphasis on improvements in building energy and water efficiency. Among the most notable changes in these categories are a new focus on metering and data sharing. The Measurement & Verification credit from previous versions of LEED has been removed in favor of prerequisites and credits focused on tracking actual energy and water consumption. Building-level meters must measure the total building energy consumption and total potable water use of the building and associated grounds to comply with the prerequisites, as well as commit to sharing this data for five years. USGBC will use performance data collected to build a database for use by future project teams in identifying opportunities for increased savings. In LEED v2009, data sharing was required under one of the Minimum Program Requirements, but projects that did not install meters could get exemptions. In LEED v4, meters and data sharing are prerequisites.

Water Efficiency

Besides the new prerequisite for Building Level Water Metering, the Water Efficiency category now includes a prerequisite for Outdoor Water Use Reduction which was an optional credit in previous versions of LEED. Projects must either demonstrate at least 30 percent reduction in irrigation from the site’s peak-watering month using the EPA WaterSense Water Budget Tool or use no permanent irrigation beyond a two-year establishment period. Additional reductions in irrigation beyond 30 percent still can be captured in the Outdoor Water Use Reduction credit. The prerequisite threshold for Indoor Water Use Reduction is 20 percent, but a requirement has been added that all newly installed fixtures must be EPA WaterSense labeled for all fixtures that are eligible for labeling. There also is a new prescriptive compliance path for meeting selected flush or flow rates. Appliance and process water use are now addressed with special requirements for the Schools, Retail, Hospitality, and Healthcare market sectors. LEED v4 also has added two new credits to the Building Design + Construction (BD+C) rating system. The Cooling Tower Water Use credit requires projects to conserve water used for makeup and control microbes, corrosion, and scale. The Water Metering credit can be earned for installing submeters for two or more water subsystems.

Table 1. Water Efficiency changes LEED v2009 to LEED v4

Table 1. Summary of Water Efficiency Changes from LEED v2009 to LEED v4

Energy Efficiency

As with other iterations of LEED, LEED v4 calls upon more stringent energy standards than the previous version. The BD+C Energy Performance prerequisite and credit now include ASHRAE 90.1-2010 as the referenced standard instead of ASHRAE 90.1-2007. The LEED O+M Energy Performance prerequisite now requires an ENERGY STAR score of 75, increased from 69 in LEED v2009. LEED v4 addresses Demand Response (DR) for the first time, evidence that DR is becoming a common green building strategy. Credit requirements include a minimum enrollment of one year with intent to renew, as well as commissioning of the DR plan and processes to verify equipment responds as planned. DR programs help utilities avoid building new power generation facilities, transmission lines, and distribution stations making systems more efficient, while also reducing greenhouse gas emissions and increasing grid reliability. In many cases, local utilities provide incentives for participation in DR programs. State Public Utilities Commission websites offer additional information about local DR programs.

Information on California Demand Response programs can be found on the Public Utilities Commission website.

Renewable energy production on-site will still contribute to LEED projects in v4 with minimal changes to the credit requirements. The Green Power credit, once earned for offsetting building electricity use only, now includes carbon offsets for offsetting non-electric sources of energy. The credit requires purchasing renewable energy certificates that have come online since January 1, 2005, for a minimum of five years. 

Table 2. Energy Efficiency Category changes from LEED v2009 to LEED v4

Table 2. Summary of Energy Efficiency Category Changes from LEED v2009 to LEED v4

Materials and Resources (MR) Category Overhaul

LEED v4’s full life-cycle approach to selecting building materials means that project teams now must combine environmental attributes and select materials that meet higher standards of transparency and optimization to meet credit requirements. Why such a drastic overhaul? USGBC hopes to increase market demand for transparency into material ingredients and the more sophisticated use of building materials attributes data. A notable change across the MR category is that the achievement of credits is now based on the number and attributes of the products selected; previous versions based credits on material costs.

Waste Management and Recycling

LEED v4 has added additional waste stream requirements for compliance with prerequisites and credits related to waste management and recycling, including requirements for the safe disposal of batteries, mercury-containing lamps, and electronic waste. A new prerequisite has been added to address construction and demolition waste management planning. This will require project teams to identify at least five materials targeted for diversion, in addition to creating a goal and a plan for diversion. The construction waste management credit thresholds of 50 percent diversion for Option 1 and 75 percent diversion for Option 2 remain the same, but now teams must include a minimum of three material streams to comply. Waste-to-energy is now considered a viable diversion strategy if the project team follows selected European Commission
Waste Framework Directives.

Building Life-Cycle Impact Reduction

Using LCA software, such as the Athena Sustainable Materials Institute LCA software package or consulting an LCA specialist likely will be necessary to perform an analysis compliant with LEED v4 requirements.

The Building Life-Cycle Impact Reduction credit, new in LEED v4, addresses environmental impacts of buildings throughout their life-of-service with a stronger emphasis on rewarding projects for reuse than previous versions of LEED. In the US, approximately one billion square feet of buildings are demolished and replaced with new construction every year, yet it can take between 10 and 80 years for a newly constructed, energy efficient building to overcome the negative climate impacts of the new construction process – sometimes longer than a building’s life of service. This credit combines the Materials Reuse and Building Reuse credits from LEED v2009 and requires reused materials to be calculated as a percentage of the building surface area, rather than materials cost. Additional compliance options include performing a whole building life-cycle assessment (LCA) for new construction, or preserving historic or blighted buildings by maintaining the existing envelope, structure, and interior non-structural elements.Life-cycle assessments for new construction must include the building’s structural elements and complete building envelope and show at least a 10 percent reduction over a baseline building in global warming potential and two of five other selected impact categories.

Building Product Disclosure and Optimization

Three new Building Product Disclosure and Optimization credits facilitate material comparisons and selection by requiring EPDs and HPDs, in addition to requirements for sourcing raw materials via some of the more traditional LEED compliance paths, with a few new twists for LEED v4.

Environmental Product Declarations

To earn the Environmental Product Declarations (EPD) credit, LEED v4 requires project teams to use at least twenty products from five different manufacturers that have either performed an LCA conforming to ISO 14044, or have an EPD. Product-specific EPDs count as one product while generic, industry-wide EPDs count as a half product. Beyond selecting products with EPD reports, project teams can obtain an additional point for optimization by selecting products that can demonstrate impact reductions in selected categories such as global warming potential, depletion of the ozone layer, acidification, and eutrophication.

Sourcing of Raw Materials

Option 1 of this credit requires project teams to use at least twenty products from five different manufacturers that have corporate sustainability reports (CSR). Third-party verified reports count as one product, while self-declared reports count as a half product. Reports must comply with USGBC approved programs, such as the Global Reporting Initiative (GRI) Sustainability Reporting Framework. Many of the Materials and Resource credits from previous versions of LEED are housed in Option 2 of this credit, which rewards projects for selecting products with recycled content, wood products certified by the Forest Stewardship Council (FSC), or salvaged materials. Products purchased from a manufacturer participating in an extended producer responsibility program, i.e. an end-of-life take back program, can also contribute via this option, as can bio-based materials (now defined as those meeting the Sustainable Agriculture Network’s Sustainable Agriculture Standard, rather than being defined by a ten year harvest cycle as in v2009).

Material Ingredients

Similar to the EPD credit, compliance with the first option for the Material Ingredients credit is met by selecting at least twenty different products whose manufacturers have committed to product disclosures. This credit requires manufacturers to disclose the chemical ingredients of a product using USGBC approved programs. Current approved programs include Cradle to Cradle (C2C) certification, a publicly available manufacturer inventory, or a Health Product Declaration (HPD). Manufacturer inventories and HPDs must publicly disclose all product ingredients and provide full disclosure of any known health hazards of these ingredients. For a C2C version 2 Basic or version 3 Bronze certification, manufacturers are required to disclose ingredients to a third-party assessor in order to achieve certification, but are not required to publicly disclose ingredient lists. By offering different options for compliance, USGBC is hoping to encourage transparency without creating barriers for achievement of this credit. For Option 1, the presence of potentially hazardous materials in a product does not disqualify the product from contributing to this credit, it simply must be disclosed.

A second option is available for projects avoiding products with known hazardous ingredients. To comply, products must have fully inventoried chemical ingredients according to the GreenScreen v1.2 Benchmark and avoid any Benchmark 1 hazards, or be Cradle to Cradle certified (Gold or Platinum (v2), or Silver, Gold or Platinum (v3)).

Sustainable Sites and Indoor Environmental Quality Updates

Sustainable Sites and Location & Transportation

The Sustainable Sites Category from previous versions of LEED was split into two categories: Sustainable Sites (SS) and Location and Transportation (LT). The LT category was borrowed from the LEED for Neighborhood Development rating system. Projects located in a LEED for Neighborhood Development certified neighborhood are automatically awarded all points in this category. Credits housed here include those for surrounding density, bike facilities, reduced parking footprint, green vehicles, and avoiding sensitive sites with minimal changes from LEED v2009. Of note are the addition of multiple thresholds for surrounding density, changes to how access to public transportation is measured (now by walking distance), addition of requirements for transit service frequency and proximity to a bicycle network, and the removal of the ‘no new parking’ option for the Parking Capacity credit, now renamed Reduced Parking Footprint. The credits that remain in the SS category now focus on the project site itself and include early analysis of the site conditions, rainwater management, heat island reduction, and light pollution reduction.

Substantive changes to the light pollution reduction credit include removal of the interior lighting requirements which are now addressed in the Energy and Atmosphere prerequisite and the addition of the BUG rating methodology. 

Indoor Environmental Quality

LEED v4 sets the bar higher for improved indoor air quality. Ventilation and Thermal Comfort credits are now based on ASHRAE 62.1-2010. Smoking in all LEED-certified buildings has been banned, except for inside private residences. The Minimum Indoor Air Quality prerequisite has been expanded to include airflow monitoring requirements previously housed in the Outdoor Air Quality Monitoring credit. Specific requirements for residential projects also have been added to this prerequisite with language largely taken from the LEED for Homes Combustion Venting credit. Low Emitting Materials credits have been updated to require VOC emissions and testing data, in addition to VOC content reporting, and now cover ceilings, insulation, and furniture for all rating systems.

What Can We Expect as LEED v4 Gets Underway?

It is easy to see that USGBC is attempting to move the building industry in a new direction with LEED v4. As project teams start requesting material ingredients and product health impacts from manufacturers, more third-party services may be created for performing whole-building and product LCAs, publishing product information disclosures, and reporting on corporate social responsibility. USGBC eventually will be able to compare energy and water use across the full LEED portfolio as projects certified under LEED v4 will have to track and report actual building energy and water use. Projects will be able to compare building performance with similar buildings and look for opportunities to maximize water conservation and energy savings. LEED v2009 will stop accepting new registrations on June 1, 2015, which should allow ample time for manufacturers and project teams to ramp up for the new rating system requirements.


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