The US Green Building Council’s LEED (Leadership in Energy & Environmental Design) green building rating system has grown through multiple versions and evolving credit requirements to consistently hone-in on the best criteria for green building design, construction, operations, and performance. Throughout its various versions, LEED standards have sought to change how buildings are constructed with the intent of minimizing the environmental impact of the built environment. By utilizing a credit system based on specific credit categories such as site selection, water conservation, indoor environmental quality, material resourcing, energy efficiency and waste reduction, the LEED rating systems provide a roadmap to green building certification through compliance to specific credit requirements within these categories.
With the evolving requirements of LEED resulting in a progression of new versions, there has been confusion for specifiers, contractors, product distributors and manufacturers regarding the credit compliance requirements for architectural wood doors. To address this confusion and understand the specific credit requirements for a given project, it is important to know both the LEED rating system version (v) a project is registered under and what the specific credits a project is pursuing. As earlier versions of LEED have historically been covered in depth, this article will outline the specific credits of LEED v4.1, the latest beta version of LEED, by outlining the credits that apply to architectural wood doors. Products may contribute to points the project earns as it works towards achieving targeted credits.
In LEED v4.1 the primary credit categories for architectural wood doors are Materials and Resources and Indoor Environmental Quality. Below you will find the description and intent of the individual credits and the requirements for credit compliance. In later articles we will address the specific credits in more detail, including how these credits relate to architectural wood doors and the various compliance options that may exist within each credit. Note that projects registered under LEED v4 may use the newer credit compliance requirements from LEED v4.1 to fulfill corresponding credit categories. There are, however, differences within the credits, so both versions should be compared to ensure the correct approach is taken to earn credits.
LEED v4.1 – Materials and Resources
The Materials and Resources (MR) category seeks to minimize environmental, energy, and human health impacts associated with the life-cycle of building materials. Through the MR credits, LEED v4.1 encourages selecting building products with sustainable methods of material extraction, manufacture, distribution, use, and disposal. There are three LEED v4.1 MR credits applicable to the wood door industry: Environmental Product Declarations, Sourcing of Raw Materials, and Material Ingredients.
Environmental Product Declarations Credit
The intent of the MR Environmental Product Declarations credit is to encourage the use of building materials that have environmentally, economically, and socially preferable life-cycle information available. To earn this credit, building projects must use at least 20 different products from at least 5 different manufacturers that have an approved Life Cycle Assessment (LCA) or an Environmental Product Declaration (EPD).¹ Some rating systems, such as Core & Shell, may require fewer products and manufacturers due to the nature of the building type, so be sure to check the specific requirements for the specific rating system the project is registered under.
LCAs and EPDs communicate life-cycle environmental impacts of a product, such as global warming potential, ozone depletion, and water pollution. A LCA is a comprehensive analysis that details the environmental impacts of a product throughout its entire life. An EPD is a shortened report, presenting the results of the LCA along with other information relating to product performance and sustainability.
To qualify for the MR Environmental Product Declaration credit, both EPDs and LCAs must have at least a cradle to gate scope. LEED v4.1 recognizes different types of EPDs. Industry-Wide Type III EPDs are third-party verified generic product declarations that apply to the same product across numerous manufacturers and has been generated from the data supplied by the participating manufacturers. Only manufacturers recognized as a participant by the LCA program operator may utilize Industry Wide Type III EPDs. Conversely, a Product-Specific Type III EPD covers a specific product from a single manufacturer. To qualify for LEED v4.1, a Product-Specific Type III EPD must either be third-party reviewed, or internally reviewed and conform to additional requirements outlined in ISO 14071.
LEED v4.1 has a second option for EPD compliance, and that is Embodied Carbon/LCA Optimization. Credits can be earned for products that show a carbon optimization report or action plan to reduce the global warming potential (GWP) of the product. Overall, the intent by LEED seems to be to reward manufacturers working towards reducing the GWP of their products by following the appropriate LCA and EPD standards, though they may not have yet achieved LCA or EPD certification.
Sourcing of Raw Materials Credit
The MR Sourcing of Raw Materials credit seeks to encourage building projects to use products verified to have been extracted or sourced in a responsible manner. To earn up to two points, at least 40% of building products by cost, sourced from at least 5 different manufacturers, must meet one or more of the responsible sourcing and extraction criteria.¹ The criteria applicable to architectural wood doors include bio-based materials, certified wood, materials reuse, and recycled content. For a complete list of the responsible sourcing and extraction criteria, please refer to the USGBC Credit Library.
Bio-based materials refer to processed materials derived from once living organisms, including cellulose fibers from agricultural products, like particle board made from wheat straw. Materials made from animal skin are excluded. Project builders using wood certified under Forest Stewardship Council (FSC), or another USGBC approved equivalent, such as SFI, can contribute to this credit under Sourcing of Raw Materials, provided chain of custody requirements are met. Materials reuse includes using salvaged, refurbished, or repurposed materials. Recycled content of a product is determined by the sum of postconsumer recycled content plus one-half the preconsumer recycled content, by weight. The higher degree to which the product meets one or more of these responsible sourcing and extraction criteria, the better the chance the project will receive two points under this credit.
Material Ingredients Credit
The MR Material Ingredients credit encourages selecting products that have known ingredient transparency information and have been screened for harmful substances. To earn credit, building projects must use at least 20 different products from at least 5 different manufacturers that demonstrate the chemical inventory of the product to at least 1000 parts per million, or 0.1%.¹ The accepted disclosure programs for architectural wood doors include Health Product Declaration (HPD), Declare, Cradle to Cradle, Living Product Declaration, and Global Green Tag. These programs assist building project teams in making informed decisions to select building products with safer ingredients that are optimized for human and environmental health. For a complete list of accepted programs, please visit the USGBC Credit Library.
LEED also provides a second option for contributing to this credit for Material Ingredient Optimization. Products may contribute under this option if they can be documented to be following an action plan towards the provided pathways for third-party certification.
LEED v4.1 – Indoor Environmental Quality
Credits under the Indoor Environmental Quality (IEQ) category focus on the indoor conditions of a building, such as air quality, lighting, acoustics and how they impact the building’s occupants. LEED v4.1 addresses IEQ to minimize building material related human health impacts, provide a comfortable environment, and enhance the well-being of building occupants. Low-Emitting Materials is the main LEED v4.1 IEQ credit applicable to the wood door industry.
The intent of IEQ Low-Emitting Materials credit is to minimize chemical air contaminants that can pollute indoor air, the environment, and threaten human health. Reducing air contaminants also contributes to an overall more productive and comfortable environment for occupants. To receive credit, building projects must use interior materials that meet the low-emitting criteria established by LEED v4.1.¹ A project may earn up to 3 points for this credit.
The low-emitting criteria for composite wood requires at least 75% of composite wood products, by cost or by surface area, must be certified Ultra Low Emitting Formaldehyde (ULEF) or No Added Formaldehyde (NAF) under TSCA Title VI or CARB ATCM. Composite wood products include all particleboard, MDF/HDF, hardwood plywood with veneer, composite or combination core, and structural wood products.¹ Architectural wood doors are categorized as a component of wall panels, which affects how the final calculation of this credit is performed under LEED v4.1
EQ Prerequisite: Minimum Acoustic Performance
This prerequisite is a requirement for BD+C: Schools, and its intent is to utilize acoustic design within schools to facilitate communication by minimizing background noise in core learning spaces. While this credit does not have specific requirements for architectural wood doors, it does reference ANSI S12.60-2010, Part 1 that does have STC requirements for doors. Care should be given that the appropriate STC level for doors is specified for a project’s specific needs as this standard also allows for the user (e.g., the school board) to determine the desired STC requirements.
Applying to specific lead versions for buildings in which sound transmission may be a significant consideration, this credit is similar to the acoustic prerequisite credit for schools in that it references ANSI S12.60-2010, Part 1. Based on the building type, other standards are referenced as criteria for compliance. Minimum STC performance levels are prescribed for various adjacent occupied spaces within the credit description. Some adjustments can be made for sound masking systems as long as the desired noise isolation levels are met. Such systems must be professionally designed. Critical for this credit is accurate door and hardware specifications which must clearly stipulate the required materials to achieve the targeted sound transmission class or noise isolation class ratings.
This credit overview should provide you with an understanding of the credits that architectural wood doors may contribute to on a project registered under LEED v4.1. In later articles we will individually address these credits in more detail, including the various compliance options that may exist within each credit. Whether a product specifier, door distributor or architectural wood door manufacturer, this series of articles should help you gain a deeper understanding of how architectural wood doors may best contribute to the LEED v4.1 projects you are working on.
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