Envelope-Based Solutions for Metal Buildings
Coordination of Envelope Systems and Building Design
An increasing percentage of roof assemblies now require insulation to be placed inside the purlin cavity as well as over the purlin. As a result, building manufacturers have to adjust their bracing systems to avoid interfering with the insulation system.
With a liner or filled cavity roof system, it is good practice to ensure the entire cavity is filled with insulation. For example, a common R-30 liner system consists of 6 inches of unfaced insulation in the purlin cavity and 3.5 inches over the purlins. With 8-inch-deep purlins and a standing seam roof, this will properly fill the cavity. However, if the building has 10-inch purlins, it will create an air gap where condensation can form. Increasing the amount of insulation in the cavity can help prevent this.
Manufacturers often offer windows, insulated doors and other accessories specifically designed for use in metal buildings. As the approach to energy performance becomes more holistic and comprehensive—and especially as the goal becomes net-zero energy—all elements will have to be considered in relation to each other. For instance, adding windows and/or skylights will come with an energy penalty, but they will enhance daylighting and potentially reduce the reliance on artificial lighting. Similarly, a roof will no longer be considered just for its impact on the building envelope but for its capacity to facilitate renewable energy. The size of a renewable energy system, in turn, will depend on overall energy demand and size of the HVAC system. Coordinating all of these elements will require more communication between the architect/engineer and builders, among manufacturers, and between manufacturers and clients.
Manufacturers who supply multiple envelope components and especially those who can leverage tools such as COMcheck to optimize assemblies will have the advantage.
CASE STUDY: BALLETTO VINEYARDS AND WINERY
Balletto Vineyards and Winery is a highly complex, seven-building project located on the southernmost tip of the Russian River Valley in Santa Rosa, Calif. The winery is a mixed-use facility that includes office space, a tasting room, a crush pad area, a fermentation room and spacious barrel storage. This project consists of a custom-engineered metal building system and IMPs.
The winery is a mixed-use facility that includes office space, a tasting room, a crush pad area, a fermentation room and spacious barrel storage. This project consists of a custom-engineered metal building system and IMPs.
The Challenge
From the very beginning, the owner established energy efficiency as one of the project’s main objectives. This directive had to be factored into a complex design that called for functional space to accommodate the different stages of winemaking and a multifaceted layout designed to create workflow efficiencies. Additionally, the project had to meet California’s Title 24 building regulations and standards. Title 24 has rigid energy codes designed for maximum efficiency; in many cases, projects are often required to meet local building standards, too. With such an extraordinary number of special needs and requirements, the project’s degree of complexity easily reached level 10, based on the Metal Building Manufacturers Association (MBMA) standards.
The Solution
To help successfully complete the project, the builder brought in the panel manufacturer who proposed an envelope-based solution that was aesthetically pleasing yet functional; most importantly, it incorporated the owner’s energy efficiency goals, which were critical to Title 24 compliance:
- Roof and wall insulation was optimized using IMPs. At the base of the building, the wall panels consist of 6-inch-thick panels, which are installed horizontally to create a wainscot up to 7 feet and 2 inches. From there to the roofline, 4-inch CF panels are installed vertically. The panels are Antique Bronze and the CF panels are Sandstone, matching the roof. Sandstone has a high solar reflective index (SRI), which contributed to the building’s LEED points.
- Superior thermal performance of the IMPs enabled the application of a night air cooling system in lieu of installing air conditioning units; this approach reduces not only energy consumption but also daily operating costs.
- Use of individual high-side wall clearstory windows maximizes daylighting inside the building without penetrating the roof.
- The single sloped roof planes and partial gable roof planes are south facing to accommodate optimum solar panel exposure.
- Incorporating the fermentation room and wine barrel storage into the winery design eliminated the need to rent an offsite warehouse for storage and also reduces fuel costs, since these work areas are within walking distance.
References
- Energycodes.gov, BECU_Codes_101
- ©2016 ACEEE Summer Study on Energy Efficiency in Buildings
- Energycodes.gov, BECU_Codes_101
- Energycodes.gov, U.S. Department of Energy: 2015 IECC Commercial Scope and Envelope Requirements; https://www.energycodes.gov/sites/default/files/becu/2015_IECC_commercial_requirements_ envelope.pdf)
- Energycodes.gov,BECU_Codes_101
- Energycodes.gov,BECU_Codes_101
- Energycodes.gov,BECU_Codes_101
- ENERGY CODES AND STANDARDS by Martha G. VanGeem CTLGroup; Revised and updated by Ryan M. Colker; Sustainable Buildings Industry Council; Updated: 10-24-2016, from the Whole Building Design Guide, a program of the National Institute of Building Sciences.
- ENERGY CODES AND STANDARDS, by Martha G. VanGeem
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Metallic Building Company manufactures custom-engineered metal buildings for numerous industries, including aviation, commercial, industrial, recreational, educational and agricultural. It serves these markets through a strong builder network as well as by working with architects to design a total envelope solution. www.metallic.com/ |
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