Decoding the New Minnesota Energy Code: Part 2
KA construction professionals and many of the architects and engineering firms they work with are learning about the new 2015 Minnesota State Building Code with the help of training designed and provided by Kraus-Anderson’s MEP Systems Coordinator Matt Stringfellow. He will present the AIA-accredited class at the upcoming Duluth Building Green Conference September 14 and the Minnesota Educational Facilities Management Professionals Association (MASMS) 2016 Fall Conference in St. Cloud on September 29.
Q: What are the highlights of the New Code?
MATT STRINGFELLOW: The new 2015 Minnesota Energy Code allows the designer to choose a prescriptive compliance path or a performance compliance path under the 2012 International Energy Conservation Code (IECC) or under the optional ASHRAE 90.1-2010 Energy Standard for Buildings Except Low-Rise Residential Buildings. Under the ASHRAE 90.1-2010 Standard there is also a sub-compliance path available under the prescriptive path option called the “Building Envelope Trade-Off Option” that allows the designer to randomly vary the performance of the building envelope components. The 2012 IECC prescriptive path option limits the designer to 30% vertical vision glass over the gross above-grade wall area (it can be increased to 40% with use of 50% daylight controls over the entire building conditioned floor area). The ASHRAE 90.1-2010 Standard prescriptive path option limits the designer to 40% vertical vision glass over the gross wall area. In addition to building envelope performance requirements, both the 2012 IECC and the ASHRAE 90.1-2010 Standard provide performance requirements for building mechanical systems, service water heating equipment, building electrical systems, and other miscellaneous systems and equipment.
Q: Briefly, what is the difference in these two paths? And how is the path determined? Which is more stringent?
MATT STRINGFELLOW: The prescriptive compliance path option will dictate to the designer, for instance, R-values that are acceptable to use for wall insulation, U-values that are acceptable to use for windows, solar heat gain coefficients that are acceptable for windows, continuous air barrier materials and assemblies that are acceptable to use, mechanical equipment performance efficiencies by equipment type that are required, watts/Sq Ft that are acceptable for lighting loads, and performance requirements for many other items, systems, and equipment that will affect a building’s energy performance. Many of these items are delineated by the climate zone in which the building is located.
The performance compliance path option, by contrast, allows the designer to vary most of the architectural and engineering components to create a proposed design for a building and then compare it to a standard reference design building of which the code defines the parameters. Under the performance path option, the proposed design building must have an annual energy cost that is equal to or less than that of the standard reference design building. The performance path analysis must be completed using a sophisticated energy modeling program such as DOE-2 or BLAST with the results documented in a report to be given to the local code official. In any case, the designer must decide which compliance path to use to meet the requirements of the 2015 Minnesota Energy Code.
It is interesting to note that the 2012 International Energy Conservation Code (IECC) was written based on the ASHRAE 90.1-2010 Standard. So the requirements in both code documents are very similar, but also with some differences. In the energy code class I teach, I provide a side-by-side comparison of some of the requirements for the 2012 IECC prescriptive path and the ASHRAE 90.1-2010 Standard prescriptive path. Ultimately, I believe that the choice by the designer on which path to use will be guided by the goals for their particular building project. Therefore, it is important for the designer to have a good understanding of the various compliance path options.
Q: What overall would you say is the biggest change in the code from the previous incarnation?
I think the single biggest change is the limitation of vision glass to 30% in the 2012 International Energy Conservation Code.
Q: What is KAU’s role in providing these trainings?
MATT STRINGFELLOW: KAU’s mission, led by Mike Smoczyk, is to identify current educational needs, identify individual(s) who can teach the various classes, provide a basic structure to help create and deliver each class, and provide a variety of related support functions. KAU provided me with training on how to effectively teach a class.
Q: What feedback are you getting on these trainings?
I have had a pretty unanimous response that the class is helpful. I think the best part of the class is an outline of the major compliance paths available, outline the main steps for each path, and the side-by-side comparison of some of the requirements for the two prescriptive paths. Each attendee gets a handy desk reference of the presentation.
Q: What’s your takeaway on doing these trainings? What have you learned from the experience?
I think that the design and construction community is a relatively small and integrated group of professionals regardless of geographic location. Often when addressing a professional education need within your own company, you can find opportunity to reach outside of your company to others in the profession and add value for them and strengthen and create new relationships.View Comments