By Dylan Salazaar, P.Eng.
Historically, building design had a strong focus on one main purpose. While other uses were not intentionally excluded, the design typically centred on that primary function, such as a performing arts venue for a narrow range of performance types or an educational facility. Recently, there is a demand for venues serving more than one purpose. Much more is being required of these spaces, but with significantly fewer resources available—be it space, money, or the ability to change from one configuration to another. These demands will only increase as cities become more densely populated and land and construction become more expensive. Financially, it makes more sense to build one space serving multiple uses.
Multipurpose venues have the opportunity to be community hubs, serving a range of purposes and a significant number of people. Having a space that can be used for more than one kind of event also provides the potential for increased revenue generation. It is common for the rental calendar at such facilities to be booked solid with a range of activities. For example, a school group might hold a graduation ceremony, a performing arts troupe may perform a concert, and a faith congregation might use it for a worship service. With demand for multipurpose venues expected to increase, these spaces must be built to offer as much flexibility as possible to accommodate these different needs, now and in the future.
From an acoustics standpoint, designing multipurpose venues can pose some challenges. Acoustics impact the comfort and experience of users. The design must consider everything from the size and shape of the space to the materials used in the furniture, walls, and ceiling, as they all can change the overall sound quality. Moreover, the venue’s acoustics will differ depending on the activities taking place—an amplified musical performance will be different than a chamber ensemble or a Shakespearean play.
With all of these considerations, it is clear when an environment was not designed for a certain use, but just making do. For a movie night, one can set-up a screen in a room, but the seating or sight lines might not be ideal. Even with a sound system, it is possible the audience will suffer from lack of immersion if the system was designed for live performance instead of theatrical exhibition.
When designing multipurpose venues, building professionals need to consider all of these possibilities, as well as their potential benefits and risks. Considering different uses means balancing the overall experience for the widest range of users. While the goal is to optimize the space as much as possible, the fact is it would be very difficult and costly to accommodate 10 different uses in one space to the same excellent standard.
Managing competing needs without compromising acoustics
This was the reality when designing Lazaridis Hall at Laurier University in Waterloo, Ont. The $103-million building is home to the Lazaridis School of Business and Economics. It features a 1000-seat auditorium that also functions as a 400-seat lecture hall.
Since the space was intended to hold lectures, convocation ceremonies, and musical performances, it was critical to manage competing needs and expectations. To ensure optimal acoustics throughout the auditorium, detailed discussions were held with stakeholders about the requirements and expectations of the space. Over those conversations, the lectures and convocation ceremonies were deemed higher priorities than the musical performances, and the acoustical design reflected this.
Main purpose of the space
As mentioned earlier, programming greatly impacts acoustical needs. Is the space going to be used for sporting events, educational sessions, musical or theatrical acoustics, or multiple purposes? A multipurpose space requires greater acoustic flexibility. Since optimizing the space for one kind of event may be detrimental to another, priorities need to be determined before design begins. It is advisable to work with the relevant stakeholders to determine the areas of focus and develop a clear understanding of the needs and expectations of the space. In most cases, a space can be optimized for only one or two key uses, so determine the primary and secondary uses, followed by potential tertiary ones.
For example, the Aga Khan Museum in Toronto required great acoustic flexibility to accommodate music performances, lectures, film festivals, and school group visits. During the design process, the stakeholders decided the auditorium’s primary use would be to support natural acoustics of eastern instruments. Its secondary use was for amplified musical performances, and its tertiary use was for film screenings. This prioritization was important because, if the goal was to optimize for speech instead of music, the acoustic design would have been different.
For Lazaridis Hall, the priority was speech, so a noise criterion (NC) of 25 was selected. This number is used to rate indoor noise (such as the noise from an HVAC system) and represents the background noise in the frequency range of 31.5 Hz to 8 kHz. Typically, the lower the NC value, the quieter the room. For reference, in an office setting, an NC rating of 25 to 30 is typical of a quiet meeting room, whereas an open office space would have a higher NC rating of about 40. Had musical performances been the top priority for the space, a more restrictive and quieter NC rating would have been used. For example, world-class performance spaces can be as quiet as N1, which is the threshold of human hearing. Other high calibre performance venues can be NC 10 or 15.