30 May BKL Helps Forge a Path Toward Better Building Envelope Acoustics
Last October, Mark Bliss, one of the Principals at BKL, presented on acoustics at the BC Building Envelope Council’s annual conference. The theme for 2018 was Stepping into the Future: Forging the Path Toward Better Buildings, and before 300 building industry stakeholders, Bliss summarized best practices for building envelope design—and even busted a few myths.
As density increases, more and more buildings are being constructed in busy areas with a variety of noise sources including traffic, industry, music events, and more, all carrying the potential to negatively affect a new building’s reputation as well as the quality of life for its residents.
Bliss discussed the health effects associated with long-term noise exposure and pointed to building envelope design as a potential avenue to facilitating the health and comfort of residents living in noisy areas. He also acknowledged that acoustical upgrades can be at odds with other design goals that building envelope professionals are working toward, namely improved energy efficiency.
He said that by evaluating a noise environment according to best practices and designing a building envelope that adequately controls noise, developers can provide residents with a comfortable acoustical space, one that facilitates rest and relaxation after a busy day in the workplace.
A key first step, explained Bliss, is evaluating the environmental noise exposure at the development site. This process sees a qualified acoustician measure the noise sources in the area, assess how that noise propagates through the neighbourhood, and calculate the noise exposure at each facade. Best practice is to conduct these calculations according to international standards.
Bliss also described how environmental noise enters a building through windows, doors, openings, walls, and the roof, and then radiates throughout the room. He cited ISO 12354-3 as the go-to standard for this component of the assessment.
Since windows are often the most significant path for noise to enter a building, Bliss spent a few minutes debunking myths about windows and sound isolation. For example, some believe that triple glazing provides better acoustical benefits than double glazing, yet Bliss explained how triple glazing can sometimes provide less benefit than double glazing.
The presentation also included a series of case studies of typical envelope-related noise control challenges. Looking at various scenarios including a heritage refit, a new energy-efficient building in a very noisy area, and a multi-family dwelling with large windows, Bliss provided details for upgrading windows and exterior walls to reduce the level of environmental noise entering the residences. He also stressed the importance of using open-cell insulation in wall cavities.
Noise from road, rail, and air traffic; industry; community events; and more can affect comfort and quality of life for anyone living in a busy neighbourhood. Bliss showed how selecting strategically placed design elements and avoiding weak links (and design myths!) can upgrade a building envelope’s ability to control noise, something that benefits residents and developers alike.