While the headline may sound dire, it's not an indication that the US Army is giving up on green building. Instead, the Army has announced it will use a new construction code of its own which is based on the ASHRAE 189.1 standard for new buildings and renovations, rather than continue to use LEED or the High Perfromance Sustainable Buildings standards. This new standard will "govern all new construction, major renovations and leased space acquisition." The Army had already adopted ASHRAE 189.1 late in 2010.

Some of the impetus for this change is political. In 2011, Congress acted to prevent any Department of Defense project from achieving LEED gold or platinum certification as part of that year's Defense Reauthorization bill.

Moreover, LEED is fundamentally a marketing program that recognizes buildings built to a particular high standard of performance. At its core, the Army is more concerned about having better buildings that it can operate more efficiently. Deputy Under Secretary of Defense Dr. Dorothy Robyn stated that, "With more than 300,000 buildings and 2.2 billion square feet of building space, DoD has a footprint three times that of Wal-Mart and six times that of GSA. Our corresponding energy bill is $4 billion annually." The Defense Department recognizes the importance of green buildings for its overall operational effectiveness.

The armed forces have been one of the biggest early adopters of LEED, and if all of the services are going to move away from using LEED as their standard for improved performance, that is likely to have a strong effect on USGBC, GBCI, and the LEED program as a whole. "The repercussions of this announcement will be widespread," notes Green Building Law Update. "For federal contractors, this is a game changer. The LEED AP credential will be less valuable. Past performance highlighting LEED certification will be less valuable, if not totally irrelevant."

ASHRAE 189.1 is not some lesser standard. It was develeoped by ASHRAE (the professional organization of mechanical engineers), US Green Building Council, and IESNA (the professional organization of lighting engineers), as well as the International Code Council. Moreover, the Army's action is not unprecedented. The International Code Council has also developed the International Green Construction Code (IGCC) which incorporates the ANSI/ASHRAE/USGBC/IES Standard 189.1 as a "jurisdictional compliance option." Increasingly, building codes are going to directly incorporate green measures instead of relying on third-party standards that are merely optional.

Ultimately, this may push LEED in new directions. LEED was meant to push the envelope and to transform the marketplace. In that respect, it has accomplished much of that initial goal. As the industry has moved to embrace LEED, perhaps in the coming years, LEED will again push for even greater improvements in building technology and again make LEED an indication of a truly elite building.

via: Green Building Law Update

Wood is a versatile construction material. It has been used for thousands of years. It has low embodied energy compared to many other building materials, and it serves to sequester carbon. But, compared with steel, it is relatively weak, and that, combined with its inherent combustability, has meant that wood is not used for structures more than a few stories tall. Now, a new development in wood construction called cross-laminated timber (CLT) is making new possibilities available in wood construction.

Cross-laminated timber panels are like massive plywood boards. Instead of shaving a log into a veneer and then gluing it together to make a board a few eighths of an inch thick, a CLT panel is made from pieces of sawn wood and is several inches thick. Like plywood, alternating layers are laid perpendicular to one another, so that the finished panel is stronger and more dimensionally stable than plain wood would be.

Because the panels are many inches thick, there is an inherent fire resistance to the material, which, in the event of a fire, will char on the outside but will not burn through quickly. Construction with CLT is also faster and requires fewer workers and lighter equipment, which can make construction more affordable.

The Stadhaus is a 9-story residential building in London which was built using CLT and is the tallest modern building constructed with wood. At present, CLT is primarily a European development, but fabrication plants are under construction in the US, and CLT panels should start to be available within a couple of years.

image: Wood in Design

via: JetsonGreen and BC Forestry