GREEN BUILDING CONSIDERATIONS OF FENESTRATION

The green building movement in this country has given rise to quantifiable rating systems that seek to establish specific levels of achievement in the creation and performance of green buildings. The best-known of these green building rating systems has been developed by the US Green Building Council and is known as the LEED rating system. This is actually a family of ratings that apply to different building situations (e.g., new or existing buildings, core, and shell, interiors) and in some cases building types (schools, healthcare, retail, homes, etc.). All of the LEED rating systems have been subject to ongoing changes and updates since their inception, but the basic categories of defining green buildings have remained the same across the different versions over time. With that in mind, the contributions that operable glass walls can fall into several green building categories.

Bi-folding Windows Case Study

Photo courtesy of CRL; © Geoff Captain

Project: Ballast Point, Long Beach
Location: Long Beach, California
Architects: Smith Consulting Architects

The Project: Ballast Point Brewing Company is one the largest and fastest growing breweries in California. The brewery recently opened the doors to an impressive 11,427-square-foot tasting room and kitchen in Long Beach, California.

The Design Concept: The goal behind the design was to create a nautical theme to coincide with Ballast Point’s corporate branding. The layout would also have to capitalize on the beautiful views of the surrounding marina, so glass became a substantial component of the building’s architecture.

The Fenestration: Various types of glazing systems were required, all supplied by the same manufacturer. The tasting room’s entrances feature a streamlined door rail system with panic handles and a product design that secures glass panes by applying pressure evenly on both sides. This produces steadfast holding power and expedites installation. Select interior areas employ a glass railing system that is ICC-ES approved. The exterior of the building has two stairways that lead to the second-level deck. The stairways utilize a glass railing system. Using minimal hardware, the system lends a contemporary accent to the classic nautical theme of the tasting room. To create a comfortable environment for guests, outside seating areas are lined with glass windscreens. The screens incorporate large glass panes with subtle aluminum framing to preserve views while acting as a barrier against air currents. Finally, the bar that services the outdoor area features a bi-folding window system. Panels conveniently stack to the side, creating a large opening that lets fresh air in and gives patio customers bar access.

The Result The latest Ballast Point Tasting Room & Kitchen aimed to create a vibrant environment with inspiring views. A single-source glazing solution helped realize the aesthetic intent by placing the surrounding scenery at the forefront using minimal hardware.

Energy and Atmosphere

As a primary part of the building facade, a computerized energy performance model can be developed based on using the appropriate NFRC ratings for U-factor, Solar Heat Gain Coefficient, Visible Transmittance, and Air Leakage if available. Further, the coordination between using natural daylight and electrical lighting should be incorporated as part of the computer model for total energy performance. Adjusting or changing the fenestration design of different facades on a building can yield significant differences in energy performance. Building variables can include high-performance triple-glazed windows, super-insulation, an airtight building shell, limitation of thermal bridging, and balanced energy recovery ventilation. Therefore, it is common to run several energy performance models with some of these different attributes to compare the impacts of those differences on a specific building and facade design. For accuracy, the data used for the computerized model should reflect the actual values obtained from the manufacturer’s tested products, not generic values.

Materials and Resources

The aluminum components of a fenestration system can contain significant recycled content. Further, glass and aluminum components can be salvaged and re-used in other buildings or recycled at the end of their service life. The pre-manufactured nature of the products reduces the amount of construction waste and scrap materials. All of these attributes help to reduce their environmental impact which can be demonstrated in a life cycle assessment (LCA) or environmental product declaration (EPD) for these products. Some industry-wide versions of these documents are available for fenestration products, but, where available, it is always advisable to obtain specific information from a manufacturer.

Indoor Environmental Quality

The addition of daylight into a building is clearly the strongest contributor of fenestration to this LEED credit category. Daylight has been shown to provide human health benefits as well as productivity boosts. Clear glazing in building facades can also be designed to provide appropriate views as well, which is also recognized as an indoor environmental quality issue in LEED. Operable windows and doors, particularly bi-fold and sliding door systems, also allow for beneficial natural air ventilation into a building. Further, for systems that avoid sealants and adhesives, requirements for low-VOC emitting materials can be met. This is carried through in the prefinished nature of the panels since no paints, coatings, adhesives, or sealants are needed.

Innovation in Design

With green design, size matters. Building size is a significant contributing factor to resource efficiency and, in the end, will affect energy use also. The move to smaller and more efficiently planned spaces makes flexibility, functionality, and expansion capabilities all the more important. Sliding and bi-folding glass walls do just this, whether in an exterior wall providing a variable connection to the outdoors or in an interior space allowing for different room configurations with the operable glass wall opened or closed.

As part of an overall building design, large format high-performance fenestration systems can be a significant part of achieving LEED certification or a similar green building recognition. Fixed systems become part of the continuous air, water, and thermal barriers of a building. Operable systems are dynamic and need to provide those same barrier characteristics when closed, but obviously, allow the desired free flow of air and temperature when open.