LEED Rating System
he U.S. Green Building Council (USGBC) developed the Leadership in Energy and Environmental Design (LEED) green building rating system. The LEED program provides third-party verification that a building project has reached one of four levels of LEED certification (Certified, Silver, Gold or Platinum) by meeting a given number of point-based credits within the rating system. LEED has evolved dramatically since its inception in 1998. The latest version is known as LEED version 4 with a focus on different building types and renovation types. The LEED Building Design and Construction (BD+C) reference guide focuses on eight building types, one of which includes new construction. Visit www.usgbc.org/leed/v4 for a copy of LEED v4 rating systems and reference guides.
Metal building systems can be used to earn a number of credits in the LEED rating system. The following includes a brief summary of possible metal building project credits in the LEED v4 BD+C rating system for new construction only:
| CREDIT NAME | # OF POINTS | METAL BUILDING APPLICATION TO CREDITS |
|---|---|---|
| Surrounding Density and Diverse Uses | Up to 2 | Metal building systems (primary, secondary, cladding) are shop fabricated and erected on-site with the ability to minimize the need to stray too far from the building perimeter. |
| Rainwater Management | Up to 3 | Metal roofs provide excellent platform to collect quality rainwater for non-potable uses. Rainwater from metal roofs tends to be cleaner than water collected from other roof types. |
| Heat Island Effect | Up to 2 | Metal roofs are ideal for reducing heat island effects (i.e. cool roofs) with various paint coating to achieve the intended Solar Reflectance Index (SRI) value. This applies to building roof and parking lot-canopies for short term and long-term SRI performance. |
| Outdoor Water Use | Up to 2 | By way of the Rainwater Management program, the quality non-potable water may be implemented to reduce municipality water use for landscaping, toilet and urinal flushing, along with custodial uses. |
| Indoor Water Use | Up to 6 | |
| Optimize Energy Performance | Up to 18 | Metal building envelopes insulated to or above the base-energy codes, along with cool roof coatings, optimize the energy performance as validated through energy models. HVAC systems may be downsized with a thermally efficient building to help reduce electrical loads. |
| Renewable Energy Production | Up to 3 | Photovoltaic (PV) panels and solar thermal units attached to the metal roof profile provide a platform for renewable energy production. |
| Building Life Cycle Impact Reduction | Up to 5 | Adding an edition onto an existing metal building or dismantling and reusing parts of the building helps achieve Building and Material Reuse option for 2 points. Whole-Building Life-Cycle Assessment option for 3 points is ideal for metal buildings when using Whole Building LCA software like the Athena Impact Estimator software. MBMA contributed industry-wide LCI data and the metal building specific drop down menus help the designer to achieve this credit. |
| Building Product Disclosure and Optimization - Environmental Product Declarations | Up to 2 | The MBMA industry-wide LCA Final Report meets the requirement of publicly available, cradle-to-gate LCA, critically reviewed conforming to ISO 14044 standard to help earn credits. LCA Final Report available here. The three MBMA industry-wide EPDs that conforms to ISO 14044 and ISO 21930 with the cradle-to-gate scope also helps earn credits. The EPDs are available here. |
| Building Product Disclosure and Optimization - Sourcing of Raw Materials | Up to 2 | Metal building manufacturer's lists may provide the information to meet the Raw Material Source and Extraction Reporting option. The Leadership Extraction Practices option includes the list of traditional single-source attributes, such as recycled content, materials reuse, etc. The recycled content is a strong point for metal building construction. Steel is the only material with the approved default recycled content of 25%. Many steel producers and metal building manufacturers publish their true recycled content to increase the percentage for calculation purposes. |
| Construction and Demolition Waste Management | Up to 2 | Shop fabricated metal buildings systems provide limited on-site construction waste, thereby likely generating not more than 2.5 lbs of waste per square-foot of building area. |
| Low-Emitting Materials | Up to 3 | VOC emissions off the painted or primed metal building structure is limited. By in large, paintings and coatings applied to the steel are applied off-site and does not affect the VOC calculations within this credit. |
| Daylight | Up to 3 | As metal buildings incorporate a variety of windows, side-lights and skylights to help achieve this credit. Light transmitting panels installed on the metal roof or wall area may also include diffusers to enhance the lighting area. |
