LEED vs. NGBS: What Works Best for Roofing?
In 2007, the National Association of Home
Builders (NAHB) and the International Code Council (ICC) partnered to establish
a much-needed and nationally recognizable standard definition of what is meant
by “green” building.
In 2007, the National Association of Home Builders (NAHB) and the International Code Council (ICC) partnered to establish a much-needed and nationally recognizable standard definition of what is meant by “green” building. Designated officially as ICC-700-2008 National Green Building Standard, this ANSI approved document defines green building for single- and multi-family homes, residential remodeling, and site development projects. On most counts, the program has been a resounding success.
“This standard (NGBS) really takes into account how we build,” said Sanford Steinberg, AIA, CGP and principal of Steinberg Design Collaborative LLP in Houston. “It is more about conservation and was specifically designed for residential and multi-family construction.”
Steinberg received his certification as a Certified Green Professional (CGP) in March 2009 after NGBS was fully adopted by the construction industry.
“The majority of my clients are all bidding to this standard,” said Steinberg. “At some point, this (NGBS) level of green building is going to be required.”
The AIA committee’s research took about four months and included interviews with local raters and verifiers for both programs, as well as discussions with the U.S. Green Building Council (promulgator of LEED) and NAHB officials.
Chairperson Andy Corn of RWA Architects says he believes the report is the first in-depth comparison of LEED and the newer NGBS.
The four-member committee found the two programs are similar in their breakdown of divisions such as water, site, and energy. A side-by-side comparison of credits showed further similarities.
“We felt the credits addressed through the NGBS were ample enough and similar enough to say that the two programs have very similar intents,” said Corn.
Differences arose when they looked at the two systems’ mandatory minimum performance levels for construction products, such as roofing, and mandatory site testing requirements. While LEED mandates a minimum site-tested performance that is equivalent to Energy Star® certification - either by a prescriptive or a performance path - the NGBS does not require a site-tested minimum performance. “It can be said that LEED is too restrictive in this requirement and NGBS is more flexible since NGBS has fewer mandatory measures,” the report states. “While the LEED mandatory measures do limit the flexibility of choice, in the opinion of the committee they ensure a minimum and effective level of performance.”
The NGBS requires higher point totals within each construction division as higher certification levels are sought, while LEED does not require higher point totals within each division when seeking higher tier certification. This allows for a project to be strong in several divisions, and weak in others, such as roofing, according to the report.
“The committee applauds the NGBS requirement for higher point totals within each division as higher certification is sought, thus creating a more balanced project,” the report reads.
Furthermore, the committee found that on average, NGBS certification costs about $800 less per project than LEED certification, and NGBS approval takes a lot less time. While NGBS projects often are certified in days, Corn noted that some LEED projects in Cincinnati have taken up to six months for final approval. Steinberg says the cost differential between LEED and NGBS can be “tremendous.” He cites a $15,000 certification process for a recent project with NGBS, compared to as much as $100,000 for third-party LEED certification.
It is also important to note that the ICC - author of the International Building Code - is also co-author of the NGBS.
“I would suggest that the industry get on the (NGBS) bandwagon right now,” said Steinberg. “The requirements of this standard are not going to be options for very long.”
In 2007, the National Association of Home Builders (NAHB) and the International Code Council (ICC) partnered to establish a much-needed and nationally recognizable standard definition of what is meant by “green” building. Designated officially as ICC-700-2008 National Green Building Standard, this ANSI approved document defines green building for single- and multi-family homes, residential remodeling, and site development projects. On most counts, the program has been a resounding success.
“This standard (NGBS) really takes into account how we build,” said Sanford Steinberg, AIA, CGP and principal of Steinberg Design Collaborative LLP in Houston. “It is more about conservation and was specifically designed for residential and multi-family construction.”
Steinberg received his certification as a Certified Green Professional (CGP) in March 2009 after NGBS was fully adopted by the construction industry.
“The majority of my clients are all bidding to this standard,” said Steinberg. “At some point, this (NGBS) level of green building is going to be required.”
Comparing LEED and NGBS
In May of 2010, the first-ever comparison of the nation’s top two green building rating systems - LEED and NGBS - was conducted by the City of Cincinnati. The American Institute of Architects completed the study for the city’s Office of Environmental Quality.The AIA committee’s research took about four months and included interviews with local raters and verifiers for both programs, as well as discussions with the U.S. Green Building Council (promulgator of LEED) and NAHB officials.
Chairperson Andy Corn of RWA Architects says he believes the report is the first in-depth comparison of LEED and the newer NGBS.
The four-member committee found the two programs are similar in their breakdown of divisions such as water, site, and energy. A side-by-side comparison of credits showed further similarities.
“We felt the credits addressed through the NGBS were ample enough and similar enough to say that the two programs have very similar intents,” said Corn.
Differences arose when they looked at the two systems’ mandatory minimum performance levels for construction products, such as roofing, and mandatory site testing requirements. While LEED mandates a minimum site-tested performance that is equivalent to Energy Star® certification - either by a prescriptive or a performance path - the NGBS does not require a site-tested minimum performance. “It can be said that LEED is too restrictive in this requirement and NGBS is more flexible since NGBS has fewer mandatory measures,” the report states. “While the LEED mandatory measures do limit the flexibility of choice, in the opinion of the committee they ensure a minimum and effective level of performance.”
The NGBS requires higher point totals within each construction division as higher certification levels are sought, while LEED does not require higher point totals within each division when seeking higher tier certification. This allows for a project to be strong in several divisions, and weak in others, such as roofing, according to the report.
“The committee applauds the NGBS requirement for higher point totals within each division as higher certification is sought, thus creating a more balanced project,” the report reads.
Furthermore, the committee found that on average, NGBS certification costs about $800 less per project than LEED certification, and NGBS approval takes a lot less time. While NGBS projects often are certified in days, Corn noted that some LEED projects in Cincinnati have taken up to six months for final approval. Steinberg says the cost differential between LEED and NGBS can be “tremendous.” He cites a $15,000 certification process for a recent project with NGBS, compared to as much as $100,000 for third-party LEED certification.
It is also important to note that the ICC - author of the International Building Code - is also co-author of the NGBS.
“I would suggest that the industry get on the (NGBS) bandwagon right now,” said Steinberg. “The requirements of this standard are not going to be options for very long.”
