Leadership in Energy and Environmental Design version 4 (LEED v4) is the latest incarnation of the revolutionary green building rating system.
According to Mark Thimons, vice-president, sustainability at the U.S.-based Steel Market Development Institute, it’s also providing more opportunities for builders to earn points by choosing steel.
"LEED has always rewarded recycled content," says Thimons. "In this version of LEED, we’re seeing opportunities for steel in a revamped materials section including credits for life cycle assessment, environmental product declarations (EPDs) and transparency."
"Both the U.S. and Canadian versions of LEED v4 are identical regarding materials and resources (MR) credits for LEED-certified projects," says Mark Hutchinson, vice-president, green building programs, with the Canada Green Building Council. MR credits focus on "minimizing the embodied energy and other impacts associated with the extraction, processing, transport, maintenance and disposal of building materials."
Under LEED for New Construction and Major Renovations (v4), there are five MR credits available for many steel products, for a total possible 13 LEED points:
■ Building life-cycle impact reduction (up to five points)
■ Building product disclosure and optimization — environmental product declarations (up to two points)
■Building product disclosure and optimization — sourcing of raw materials (up to two points)
■Building product disclosure and optimization — material ingredients (up to two points)
■Construction and demolition waste management (up to two points).
The building product disclosure and optimization (BPDO) credits offer two levels of compliance. Disclosure involves providing documentation about some of the building material products used in a building project. Optimization involves assurances that a percentage of building products complies with a certain number of environmentally positive characteristics identified in LEED — for example, preventing depletion of nonrenewable energy resources.
Steel can be a critical factor in earning points for any of these credits, says Thimons. However, he notes that steel has an advantage out of the gate because of a transparent supply chain in both new steel production and recycled steel.
"On the ‘environmental product declarations’ credit, just producing an EPD satisfies disclosure," says Thimons.
"That’s where the steel industry in general has a head start, because the industry has been working on industry-wide and product-specific EPDs to convey all of the environmental impacts over the product life cycle. There are EPDs for anything from steel doors to steel roofing, steel cladding and wall cladding and there are others in development or near completion, including cold-formed steel framing, steel deck and structural steel."
The disclosure option for the "sourcing of raw materials" credit requires a document reporting the source of raw materials using a manufacturer’s list.
"This includes not just ‘steel,’ but also the addition of a galvanized coating or paint for some products," says Thimons.
"There’s another credit for meeting recycled content, which has always been a strong point for steel. It’s still the only material approved for a default recycled content of 25 per cent. Many steel producers actually publish their true recycled content and those numbers are often higher than 25 per cent."
In fact, the Canadian Steel Producers Association says that Canada’s steel recycling rate stands at in excess of 60 per cent, with more than seven-million tonnes recycled in 2012. The US Geological Survey estimates that 72-million tonnes of ferrous scrap were purchased in the U.S. the same year.
Thimons notes that steel life — cycle inventory data can be used to demonstrate the requirements of the "building life-cycle impact reduction" credit. Through steel recycling, it can also help to achieve points under the construction and demolition waste management credit.
"Steel can also be used in roofing applications to assist in achieving the LEED heat island reduction credit for solar reflective roofing," says Thimons. "The versatility of steel, its supply-chain transparency and its continuous recyclability provide plenty of opportunities under LEED v4."