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ASHRAE Aims to Codify Green Building Practices
Febryary 22, 2011
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STANDARD OUTPACES ADOPTERS
Energy efficiency targets are now commonly expressed as an anticipated percentage of improvement in performance. This can be a convenient way to define and conceptualize the many aspects of building design, construction and operations that affect energy consumption, particularly for a less technically astute audience, but it’s an imprecise fit in the development of a forward-looking document like a building code with a five-year cycle.
"We’ve fallen into describing the energy efficiency in codes in ‘percentage better’ than the current code level. In 2011, a new building in Ontario will be expected to be 25% better than the Model National Energy Code for Buildings (MNECB), but that’s an average number. It’s an efficiency level that is the weighted average for the buildings expected to be built over the next five years,” says Bob Bach, Co-Chair of the Building Code Energy Advisory Council that provides advice on the resource conservation provisions of Ontario’s Building Code. “I personally do not like trying to evaluate the energy efficiency improvement as a single number. Nevertheless, that’s what ASHRAE is doing now, that’s what building codes are doing and that’s what the politicians are doing, so we’re stuck with it.”
Continual adjustment of targets in the ASHRAE 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings also has code developers and enforcers scrambling to keep pace. Most codes are revised at lengthier intervals than ASHRAE’s three-year cycle. For example, Ontario has gone from referencing 90.1-2004 in its current building code to considering 90.1-2010 for its 2011 code, while entirely skipping over 90.1-2007.
“ASHRAE is a juggernaut,” Bach asserts.
In contrast, a new National Energy Code for Buildings slated for release in Canada this year will follow 14 years after its predecessor. ASHRAE’s dominance and the sparse adoption of the circa 1997 MNEBC (it is referenced only in the Ontario Building Code and the Vancouver Building By-law) are believed to be among the reasons for the reluctance of the Canadian Commission on Building and Fire Codes to update the MNECB earlier.
American practitioners report some similar obstacles. “Most U.S. states have yet to catch up to 90.1-2004 let alone the 2007 or 2010 versions,” observes Lindsay Audin, President of the U.S. based energy management consulting firm, Energywiz Inc. “The extra costs involved with each standard and the very poor enforcement thereof – many building inspectors lack training in any energy standard – make it easy during a recession to look the other way during the design and installation processes.”
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Imminent Adoption Unlikely in Canada
By Barbara Carss
A new standard for high-performance buildings replicates much of the substance of the LEED program, but with the aim of making criteria enforceable in building codes and by-laws. This includes prescriptive or performance-based paths that will also be a compliance option for the International Green Construction Code, which is now in development and anticipated for release in 2012.
ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) already sets a widely recognized bar for energy performance through ASHRAE 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, which underpins requirements mandated in codes and regulations throughout the United States and some parts of Canada. The new ASHRAE 189.1, Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings, sets even more ambitious energy efficiency targets, while broadening the scope of criteria to encompass sustainable sites, water efficiency, indoor environmental quality, sensitive use of resources, and construction and operational plans.
“It was written in code language,” Tom Lawrence, an ASHRAE Public Associate and Professor of Engineering at the University of Georgia, told seminar attendees at the recent PM Expo in Toronto. “The intent was to bring into the building code high-performance green building practices.”
Nevertheless, green building and energy management specialists predict the standard is more likely to serve as a progressive design guideline for developers and building owners who will voluntarily apply it, particularly in Canada where the 2010 edition of the National Building Code has just been released and the next version is not due until 2015. Nor have other jurisdictions with their own building code cycles indicated anything but scholarly interest.
“We have been studying it since it was published in January 2010,” reports Bob Bach, Co-Chair of the Building Code Energy Advisory Council that provides advice on resource conservation provisions in Ontario’s Building Code. “The Ontario Ministry of Municipal Affairs and Housing Building and Development Branch, which writes the Building Code, is considering the expansion of objectives to include more things that affect the sustainability of buildings, but I think it’s too early in the development of 189.1 for Ontario to jump in and adopt it. This is a whole new area for ASHRAE to get into. It needs to be seasoned somewhat.”
HEIGHTENED TARGETS
Energy requirements have been accentuated to deliver the targeted 30% greater efficiency than ASHRAE 90.1-2007. However, Lawrence noted that the more recent 2010 version of that standard is also 20% more efficient than its predecessor.
“That was the plan. Both of them [90.1 and 189.1] are on a continuous maintenance process,” he said. “90.1 will continue to go down [in the future], but not at the same rate.”
Under the prescriptive approach, key building systems such as HVAC, lighting, elevators/escalators and plug loads must be metered and have remote automatic meter reading with data storage for a minimum of 36 months. Some of the other requirements include: demand-control ventilation at an occupancy threshold of 25 people per 1,000 square feet; mechanisms, excluding standby generation, to reduce peak demand by 10%; and flexibility to accommodate on-site renewable energy generation in the future.
Lighting must be 10% more efficient than the level of the 90.1 standard. “Lighting technology is getting better and better, but with 90.1 it’s still kind of old school in terms of technology,” Lawrence observed.
Developers and building owners who opt for the performance-based path don’t have to implement every identified feature, but they must conduct energy modelling to demonstrate that their design will perform at the same level as a building that contains the prescriptive measures. Regardless of the path chosen, Canadian observers offer some qualifiers, noting that ASHRAE’s assumptions are largely based on U.S. construction methods and climatic conditions that don’t translate exactly in other regions.
CANADIAN APPLICATIONS DIFFER
“The energy savings associated with ASHRAE 90.1-2010 are similar to ASHRAE 189.1 for our climate zone,” notes Dave Ramslie, Manager of the City of Vancouver’s Sustainable Development Program. “Our moderate weather makes savings more difficult so typically model code savings are smaller [here].”
“We build differently and our buildings have different loads. The numbers are based on U.S. building stock and they do not apply verbatim to Ontario buildings,” Bach concurs. “The reason building codes are a provincial responsibility, or a state responsibility in the U.S., is because buildings are designed and constructed as a result of local materials, climate, culture and economics.”
Vancouver, which is largely unique in Canada in developing and adopting its own municipal by-law to regulate the design and construction of buildings (most municipalities, except Vancouver and some in Quebec, are subject to the building code of the province in which they are located), is currently studying the feasibility of adopting ASHRAE 90.1-2010 into the 2011 updated version of the Vancouver Building By-law.
By-law developers don’t see a need for ASHRAE 189.1’s wider coverage of water use or site considerations. “We regulate those items via other policy tools,” Ramslie explains.Similarly, Ontario’s Energy Advisory Council already includes one designated water use specialist, but the recently adopted Water Opportunities and Conservation Act includes an amendment to the Building Code Act to mandate a review of water conservation standards at five-year intervals. “There is a provision that our Council will expand to specifically address water,” Bach says.
On the energy front, the Ontario government has stipulated that the 2011 Building Code must achieve 25% better energy efficiency than the standards set in Canada’s circa 1997 Model National Energy Code for Buildings (MNECB). Ontario’s current code, which was released in 2006, gives builders a choice between ASHRAE 90.1-2004 or the MNECB, in combination with some supplementary requirements spelled out in the building code.
Researchers are now weighing the performance outcomes of the new National Energy Code for Buildings (NECB) slated for release later this year against the ASHRAE 90.1-2010 standard, although this has been something of a challenge given that the National Energy Code is not yet finalized.
“We are trying to evaluate how much greater efficiency, on an average basis, could be achieved over the Ontario Building Code as it currently exists if we adopted the NECB or ASHRAE 90.1-2010,” Bach says. “In the research, they are getting a line-by-line comparison of the requirements for Standard 90.1-2010 versus the NECB versus the current Ontario Building Code. I suppose it could also be useful to compare 189.1 against 90.1-2010.”
OVERLAP & OBSTACLES
Beyond energy, provisions relating to sites, water use, indoor environmental quality, use of materials, and impact on atmosphere and resources overlap with many of the prerequisites and eligible points in the LEED program and/or various planning and local regulations that developers may encounter in their own jurisdictions. For example, the Toronto Green Standard for new development addresses the same issues relating to storm water runoff, heat island effect, light pollution and appropriate choice of plantings that ASHRAE 189.1 covers, and, in fact, imposes stricter measures in some cases. (See www.toronto.ca/planning/greendevelopment.htm.)
In the indoor environmental quality category, ASHRAE 189.1’s complete ban on smoking inside the building could present some challenges for compliance, especially in multi-residential buildings. Likewise, ongoing operations and maintenance are always problematic to address in a building code primarily meant to govern design and construction, but ASHRAE 189.1 would require that developers/owners at least create plans for operations and maintenance. These would be a mandated component of construction documents to guide site sustainability, energy and water use and indoor environmental quality into the future.
“LEED only gets into some aspects of operations, but this takes it to a whole next step,” Lawrence said. “We are making people at least think about how they are going to operate their buildings. That’s all we can really do legally.”
For now, ASHRAE 189.1’s value may lie primarily in that consciousness raising realm and/or in providing guidance for municipalities looking to enhance sustainability standards or for developers, owners and investors who want to set sustainability goals and conditions in their own portfolios. “It’s written in code language so it can be adopted in a building code, but it is intended, I think, to provide a baseline for how to design and build a green building,” Bach suggests.
For more information about ASHRAE 189.1, see the web site at www.ashrae.org/greenstandard.
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