Grant: Alliance Grants

Mass timber construction has become more popular in the building industry as it is more sustainable, efficient, and economical than conventional construction materials. The majority of recent development in mass timber buildings has focused on technical issues such as structural strength, fire safety, and cost-effectiveness with the aim of extending the technology to high-rise buildings. In comparison, the acoustic performance of mass timber buildings has received minimal attention. In fact, their poor acoustic performance has been a key barrier to promoting timber construction. Especially impact noise, such as footsteps from neighbors, is difficult to attenuate due to its structure-borne nature and the dynamic property of the mass timber. The current standards on impact sound evaluation methods do not effectively quantify occupants' annoyance as they are designed for conventional materials such as concrete. It has been shown that the existing standards are not reliable for predicting the impact noise levels for a mass timber floor assembly. On the other hand, the acoustic impedance and dynamic characteristics of mass timber floors are not fully understood yet. Thus, there is a critical need at the design stage for understanding and predicting how building occupants perceive impact noise in mass timber buildings. A more efficient design alternative can be developed by identifying the crucial acoustic components that affect human annoyance and offering feedback on the mass-timber floor design. To address this need, this project aims to develop an innovative mass-timber floor system to improve impact sound insulation in mass timber construction using human-centered design optimization and metamaterial. The objective will be carried out by an interdisciplinary team in the area of building acoustics, psychoacoustics, vibration, and timber engineering in British Columbia and Quebec.