by Rose Mary Su
As acoustics, noise, and vibration consultants serving many of the metro Boston building developments, Acentech has seen a recent uptick in developers converting spec office buildings to lab or lab/office buildings. This conversion has some impacts that should be taken into consideration as they relate to acoustics, noise, and vibration.
Spec lab buildings will typically require more demanding ventilation systems than spec office buildings. This typically includes cooling towers and high-plume exhaust fans that produce more noise to the community. The emergency generators are noise sources that also need to be addressed. A spec lab building will generally require more stringent vibration criteria to accommodate vibration-sensitive equipment. This is especially the case for life science, chemistry, and other wet-lab research-based tenants.
Project location affects our recommended noise mitigation measures and the degree of complexity as they relate to the ventilation systems. For example, if the project site is located in Cambridge, the noise regulation required for mitigating building equipment noise to the community is different from Waltham. Another challenge is that some spec buildings have residential neighbors very close to the project site, while others are adjacent to commercial/industrial zoned properties. Cities like Cambridge have commercial/industrial zones that allow for a higher noise limit. Some cities and towns have building height restrictions and many of the noise control options would impact the overall height of the rooftop equipment or the noise barrier.
Another important consideration is whether the spec building is an existing or new building. Due to the frequent need to provide noise barriers around large rooftop equipment to mitigate noise to the community, this addition can have a higher impact on the structural design for an existing building than a new building.
Project location also affects our recommended vibration mitigation methods and the degree of complexity. A building located adjacent to a subway or a train line will have a higher likelihood of the transmission of vibration into the building. Unlike spec office buildings where the noise and vibration perception tolerance is relatively high, precision instruments such as electron microscopes have much lower tolerances for intrusive noise and vibration.
Oftentimes, not being able to identify the tenant program prior to designing the spec building can make it a challenge to determine the appropriate level of vibration criteria and mitigation. While this is the case, some educated decision making is needed to reduce over-design or under-design of the building.
Depending on the targeted lab tenant, it may be possible to identify whether the tenant would likely require stringent acoustics and vibration criteria for the fit-out. For example, for a more mature biotech research company, there is more desire and financial resources to have in-house equipment, such as electron microscopes. For start-up companies that cannot afford to have in-house equipment, the tenant may choose to outsource such services to other institutions or commercial services with such equipment.
At minimum, the spec lab building should allow for general bench microscopes to be functional. For new buildings, having floor plates that are relatively open and column-free make it difficult to meet the desired vibration criteria relative to the movement of people in the building. A good design approach would be to identify zones on each floor plate that would be suitable for vibration sensitive equipment. Existing buildings would benefit by conducting site vibration surveys to help establish the appropriate lab tenants. Otherwise, more complex structural upgrades may be necessary, if that is even an option.
Regardless of whether the building is new or existing, early evaluation and understanding of the site can help avoid many of the costly noise and vibration mitigation measures needed for a spec lab building.
Rose Mary Su is a principal consultant and the laboratory market leader at Acentech, an acoustics, noise, vibration, audiovisual and IT/security consulting firm headquartered in Cambridge, Mass.
