Home Energy Management The Advantages of High-Performance Building Envelopes

The Advantages of High-Performance Building Envelopes

Joe Pasma, PE

As energy costs continue to rise and building codes become more rigorous, lodging facility professionals are searching for higher-performing building envelope assemblies. One such system, structural insulated panels (SIPS), helps reduce energy consumption up to 60 percent compared to other structural systems, while providing a host of other construction and operations benefits.

An SIPs Primer

SIPs are a prefabricated, engineered building system typically used for walls and roofs. They are composed of structural-grade wood panels such as oriented strand board (OSB) laminated to both sides of a rigid insulating foam core like expanded polystyrene (EPS). The system provides both structural strength and thermal insulation.

Architects can incorporate SIPs into virtually any building design up to four stories tall, from modern to rustic, making them well suited for lodges, motels and other lodging facilities in both urban and rural settings. Building professionals have successfully used SIPs in all types of climates, from the high deserts of New Mexico to above the Arctic Circle in Alaska.

Energy Efficiency

SIPS provide an energy efficient building envelope in three ways: a near airtight assembly, solid continuous insulation and reduced thermal bridging.

It is “dramatically easier” to make a SIP structure tight, because it “has fewer joints and less complicated interfaces between conditioned and unconditioned spaces,” says Sam Rashkin, a former National Director of the U.S. Energy Star program. This is backed up by rigorous research, including testing by the U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory. The lab found that SIP structures are up to 15 times more airtight than traditionally framed walls insulated with fiberglass batts. A SIP structure’s air leakage rate was only 8 cu. ft. per minute at 50 Pascals of pressure versus stick framing with a leakage rate of 121 cu. ft. per minute.

In addition to reducing air leakage, SIPs provide solid continuous insulation across the panels’ height, width and depth for exceptional thermal performance by reducing convective looping. And, unlike traditional construction with studs, concrete or CMUs, SIPs have fewer thermal bridges to conduct heat.

Faster, More Streamlined Construction

Coming in a close second to energy savings, building professionals choose SIPs for their ability to shave weeks or months off of construction schedules. Despite producing high-performance wall and roof assemblies, SIPS are fast and simple to install. An experienced foreman and several less experienced labors are all that are needed to slide the lightweight panels together according to a numbered installation guide specific to each project. “With the pre-built panels, you just have to piece the building together like a puzzle,” said contractor Glen Kamerman, Partner with Kamerman Construction.

“Compared to stick framing, SIP walls go up much faster since they can be installed in large sections and eliminate the need for separate on-site framing and insulation work,” said Sharon Bullock, Project Manager for Community Development Programs Center of Nevada (CDPCN). “The finished walls are also beautifully straight, which saves time on drywall installation, painting and other finishing work.”

And, because the panels are delivered to the jobsite ready to install, they reduce jobsite construction waste by eliminating the need to trim numerous framing members to size.

More Lodging Facility Benefits

SIPs offer three additional benefits of particular note for lodging facilities. First, because the panels are fully sheathed, they stand up better to abuse from guests than do stick-framed walls covered with drywall. While most guests are respectful of lodging facilities, imagine a wing full of little league baseball players tearing around, or a bachelor party that gets out of hand. Fully sheathed OSB walls are less likely to have holes poked in them.

Two other benefits accrue from recently developed SIP wall assemblies: sound transmission class (STC) ratings and fire assembly ratings. One of North America’s largest SIP manufacturers, Premier SIPs, pioneered several wall assemblies using a proprietary clip, gypsum wallboard and fiberglass batt insulation, that have been independently tested to yield STC ratings up to 59—well above the 50 rating for dwelling units that is called for in the International Building Code (IBC). The clip minimizes the contact area of the various layers of the assembly, which helps decouple the assembly and reduce sound transmission. In such assemblies with double layers of gypsum, walls also achieve one-hour fire ratings, which is important for life safety in densely occupied spaces such as lodging facilities.

Cost Factors

After learning of SIPs’ advantages, building owners, contractors and design professionals who are not familiar with the panels naturally ask about the cost.

One experienced SIP builder, Clarum Homes, notes on its website: “Building with SIPs generally costs about the same as building with wood frame construction, when you factor in the labor savings resulting from shorter construction time and less job-site waste. You will also realize other savings over time because less expensive heating and cooling systems are required with SIP construction.”

Joe Pasma, PE, is the Technical Manager for Premier SIPs by Insulfoam, a division of Carlisle Construction Materials. He has more than 35 years of experience in the building industry, including structural engineering, product development, and application of building science principals. He can be reached at joe.pasma@premiersips.com.