Acoustics & Noise Control in Mixed-Use Buildings
In a world where sound plays a pivotal role in both our personal and professional lives, the demand for acoustical engineering has never been more essential. One of the most common challenges is managing unwanted noise. It is often more prevalent in urban environments, but noise can be even more noticeable in quiet suburban and rural areas. Whether noise from traffic, machinery, or nearby activities is the culprit; effective acoustic design and noise control can greatly enhance the daily experience of both workers and residents.
Imagine moving into a new apartment in a mixed-use building in a bustling downtown location. It is convenient, with a variety of nearby shops and restaurants; however, noise issues can become more noticeable soon after becoming settled. For example, a lively gym below cranks up loud music during a morning class, and noise and vibration from weight training shakes the apartment. The stylish wood veneer finish in the corridor may look great, but it is highly reflective, making it impossible not to hear every conversation as neighbors pass by.
This is the reality for many tenants in mixed-use buildings – where noise and reverberation are not only inconveniences, but deal-breakers. This is especially true in recent years, as lightweight construction methods have become more common, inadvertently worsening noise control between spaces. Poor design decisions can cause noise complaints and negatively impact customer experiences. This blog will explore why acoustical design is so crucial in mixed-use buildings and discuss the common challenges businesses and residential tenants face.
Retail-to-Retail Sound Transmission
In a bustling mixed-use building, sound travels quickly – and sound transmission can occur via both airborne and structure-borne paths. For example, a booming playlist from a fitness studio can easily disturb the productivity of a nearby office. Or the steady hum of a coffee shop can interfere with the calm atmosphere in a high-end boutique retail store. Over time, this kind of noise disruption can lead to tension between tenants.
In these scenarios, airborne paths are sounds emanating from the loudspeaker(s) or kitchen equipment. Noise is transmitted through a wall or floor-ceiling assembly and then arrives at the ears of a neighbor. Structure-borne paths are more complex. They include how the espresso machine or sound system is attached or mounted to the ceiling, wall, or table/floor. Vibrations from equipment can be transmitted through the building structure – exciting the building element to resonate and thus causing audible noise in the adjacent tenant space.
If someone is trying to shop and a loud thud from next door suddenly echoes in the store, it can lead to discomfort. Not only does unwanted noise impact the customer experience, it also affects productivity in an office. When retail and office tenants cannot enjoy their spaces without noise interruptions, action must be taken to resolve the concern.
Retail-to-Residential Sound Transmission
In the next mixed-use building scenario, apartments or condominiums are located above or beside retail spaces. A residential occupant does not want to return to a noisy apartment after a long day at work. It is especially frustrating when low-frequency noise from a retail or restaurant space below is disruptive. Late-night sounds can lead to sleepless nights. Noise issues can quickly lead to a rise in complaints, strained relationships between tenants, and, in some cases, even legal disputes.
Mechanical system noise is prevalent in restaurants and other food service spaces. Kitchens have the need for more extensive exhaust systems. Dedicated air handlers required to operate these facilities have higher noise levels and may be installed directly below an apartment or condominium. Rooftop equipment in mixed-use buildings is often located above the most expensive apartment or penthouse condominium unit in the building.
These airborne and structure-borne noise paths are similar to the retail-to-retail scenario. However, because residents live in the building at all hours of the day and night and may even work from home, excessive noise levels are tolerated less than retail-to-retail noise.
Design Considerations in Mixed-Use Buildings
Appropriate acoustical design begins during the concept or schematic design phases. Space planning involves choosing to place quiet spaces closer to other quiet spaces and noisy spaces closer to other noisy spaces. When this cannot be done, a more robust structure must be considered. When acoustics and noise control are considered later in the design, this may lead to more expensive noise control solutions.
Decisions related to aesthetics or cost often outweigh decisions related to acoustics and noise control. Open-concept layouts and hard, reflective surfaces such as concrete floors and glass walls let natural light in and are easier to clean, but they can create an echo chamber. Sound bounces off these surfaces and builds up, creating a noisy, uncomfortable space. Excessive noise levels can be transmitted through walls and floor-ceiling assemblies, especially when these assemblies have less mass.
While developing an appropriate acoustical design, demising walls, and floor-ceiling assemblies need to be designed to provide proper noise reduction. In an existing building, noise surveys are important to understand the amount of sound isolation that an existing structure provides. Measuring the noise levels from any existing mechanical systems is also important. This can help inform design decisions to provide adequate acoustics and noise control solutions.
Detailed Acoustical Design and Construction Administration
After preliminary acoustical design services are provided, it is important to stay involved in the detailed design and construction administration phases. BABICHacoustics provides architectural, structural, mechanical, electrical, and plumbing design reviews to develop customized solutions to be incorporate in the construction documents. Drawing details and appropriate coordination are provided to the design team prior to the release of contract documents. These reviews and calculations ensure that acoustical criteria are met during and after construction.
It is important for acoustical consultants to stay involved during construction and complete site visits to ensure that contractors are carrying out the design. Submittals are reviewed to ensure that the products being installed meet the design intent. Finding issues on site, such as a lack of acoustical caulking or the wrong vibration isolators, can prevent noise concerns after tenants occupy the building.
Acoustical design is important for multiple businesses and residents to coexist in one mixed-use building. By addressing noise issues during the design and construction phases, an appropriate acoustical environment can be created for everyone. BABICHacoustics has the experience to provide the necessary acoustics, noise, and vibration consulting services for mixed-use and residential buildings!