Acoustics should be a bigger piece in the building decarbonization puzzle

Jonathan Broyles – j.broyles@psu.edu

The Pennsylvania State University, University Park, PA, 16801, United States

Popular version of 5aAA6 – Acoustic design trade-offs when reducing the carbon footprint of buildings
Presented at the 184 ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0019111

The built environment is responsible for upwards of 40% of global carbon emissions and has sparked a change in how buildings are designed in an effort to mitigate the global climate crisis. Design goals to reduce the carbon footprint of a building directly affects acoustics, potentially causing unintended acoustical consequences. Yet building acoustics is often considered much later in the design of a building, if at all, resulting in missed opportunities to harmonize sustainable and acoustical design goals. Significant research is needed to further understand acoustic-decarbonization trade-offs, as preliminary results found that research at the intersection of building decarbonization and acoustic design lacks well behind other building disciplines (see Figure 1). Despite the lack of published work, several studies suggest that holistic building design solutions are possible, including the balancing the mass distribution of structures to achieve high sound insulation with less material, designing with natural materials that can reduce echoes, and selecting efficient mechanical systems that prevent unwanted noise.

Figure 1: Publication trends for five building disciplines and building decarbonization.

Building carbon emissions can be reduced by designing sustainable structural elements (including green roofs and mass timber structures) and reducing the material consumption of structures with high carbon emissions (such as concrete floors, as shown in Figure 2). Innovations in building and construction materials can further improve carbon emission savings, from reducing carbon emissions during material manufacturing and during building operation. Such strategies include the use of natural materials (including straw bales and compressed earth blocks), concrete mixes with lower cement proportions, and material optimization. Carbon emissions during the service life of a building can be reduced by selecting more efficient systems (such as multi-pane windows) and smart mechanical systems. These solutions also highlight the interdisciplinary nature of building design, as decisions in one discipline can directly influence acoustic performance.

Figure 2: Example of synergizing sustainable, acoustical, and structural design goals. Image courtesy of Broyles et al., 2023.

Many of the strategies to reduce carbon emissions while balancing acoustic design goals have important trade-offs that should be further studied. Many sustainable structures can have unfavorable sound insulation due to a lack of mass. Many natural materials deteriorate at a faster rate than conventional materials. Lastly, the upfront cost and maintenance of efficient systems can make these solutions unattractive to building owners. This emphasizes the importance for further research at the intersection of building decarbonization and acoustics to better understand how to provide sustainable solutions that benefit the planet, building occupants, and building owners. Future decarbonization technologies will need to consider the acoustic implications to prevent post-construction retrofits and other design modifications. As the building industry continues to pursue aggressive sustainable targets, a holistic approach to building design is needed to truly provide a sustainable building.