Specifying windows and doors while promoting resiliency
As the need and demand for durable homes ramps up, AIA partner Andersen Windows explores how to accommodate both glass trends and more robust building envelopes.
In the past, green building conversations have often focused on energy efficiency, water conservation, and indoor air quality. But recently the design community has also turned its attention to the concept of resiliency.
“Buildings and communities are subjected to destructive forces ranging from fire to storms to earthquakes to flooding or even an intentional attack,” AIA explains. “The challenges facing the built environment are evolving with climate change, environmental degradation, and population growth. Architects have a responsibility to design a resilient environment that can more successfully adapt to natural conditions and that can more readily absorb and recover from adverse events.”
Nadav Malin, president of BuildingGreen, notes that resilient design requires a dual approach that encompasses many aspects of sustainability: “For us, resiliency is the intersection of trying to prevent climate change and other natural disasters, [while at the same time] being prepared for them and able to respond and adapt and recover,” he says. Buildings and infrastructure must do their part to reduce carbon emissions, while at the same time be designed and built to withstand the disasters that increasingly result.
Malin points out that there’s often a sweet spot in resilient design, where strategies meet both proactive and reactive objectives. For example, a well-designed and -crafted building envelope will reduce energy use and emissions, but also will help the building survive a major wind event and remain habitable and comfortable afterward.
Increasingly stringent codes, from wind regulations developed in Florida following Hurricane Andrew to California’s new requirements for net zero homes by 2020, are playing a role in making homes more resilient. But it’s also up to the design and building communities to drive change. “Natural events are occurring with great ferocity,” notes Laurie Schoeman, senior program director of resilient communities and disaster recovery for affordable housing nonprofit Enterprise Community Partners. “We’re committed to help communities build resiliency into housing and infrastructure so that when disasters do occur they can bear the brunt.”
But designing for resiliency sometimes contradicts what consumers desire in their homes. For example, larger expanses of glass and blurred connections between indoors and out increase what is already one of the most inefficient parts of the building envelope. How can architects accommodate those demands while bolstering energy efficiency, increasing durability, and ensuring longevity? Here are a few strategies:
- Leverage glass technology: A continued innovation of energy-efficient coatings, glazing layers, and insulation are helping to increase the energy efficiency of windows and doors in both hot and cold climates, as well as provide flexibility to value engineer openings throughout each home to maximize both efficiencies and budget. In areas where high winds are a concern, the proliferation of impact-rated glass, in which a laminated interlayer prevents wind-blown debris from penetrating the structure and sacrificing the integrity of the entire structure, has played one of the most significant roles in preserving the glass homeowners crave without jeopardizing the structure. Impact-rated glass and frames are available in increasingly larger sizes and styles, promoting design flexibility as well as availability across price points.
- Leverage frame joining technology: The design pressure and impact resistance of the frame joining materials is just as important as the glass. For example, the new Andersen Easy Connect joining system for A-Series windows allows architects to design much larger window combinations and still meet the design pressure requirements for a specific jobsite as well as meeting local opening protection requirements, such as Florida’s High Velocity Hurricane Zone. The system also addresses durability in all regions of the country: The ability to join larger units on the jobsite helps reduce transport issues that may lead to damage.
- Specify a robust door system: For homes where an indoor-outdoor connection is critical but driving wind and rain are likely, Weiland LiftSlide doors from the Andersen Architectural Collection allow for 60-foot-by-16-foot expanses and feature custom hardware that lifts the door panel by engaging the wheel and allowing it to roll smoothly along a flush track. The system then easily positions the panel into place for reliable protection against weather. Similar to windows, larger doors can be specified with varying levels of efficiency and impact-resistance features.
- Look for quality: Materials that need to be replaced prematurely or don’t perform as promised do not contribute to durable, resilient homes. Specify products from established manufacturers that certify their products to third-party standards such as AAMA and Energy Star. For example, windows and doors that carry Hallmark Certification have been tested to the structural pressure, air, and water requirements referenced by the WDMA. Similarly, joints between windows and doors do not have to be air and water certified in the US, but designers should look for AAMA 450 certification to help ensure the window combination’s overall air and water performance.
- Consider the whole system: Each element of the building envelope must work together. Along with the windows and doors, include specifications for flashing, sealing, and other installation best practices in accordance with current building science-based recommendations to help prevent moisture and air intrusion and contribute to more durable, comfortable homes.
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