Acoustics

Dr Anthony Chilton

Senior Partner and Acoustics Leader

Jack Hobhouse

Designing buildings to provide comfortable, controlled acoustic environments can lead to decisions that increase operational energy and embodied carbon – but it doesn’t have to.

A low-energy, low-carbon approach to acoustic design

Applying the following strategies to the acoustic design of a building can help maximise a project’s net zero carbon potential:

  • Avoid a situation where noise precludes a natural ventilation strategy. Adjusting the orientation, massing and form of the building can reduce the noise exposure of facades. By combining these approaches with ventilation openings that incorporate sound reducing material, the provision of natural ventilation for summer cooling or fresh air can be viable on all but the noisiest sites.
  • Provide cross-laminated timber (CLT) separating constructions as an alternative to in-situ concrete. Structural CLT has lower embodied carbon but also poorer sound insulation than concrete due to its lower mass. Additional acoustic enhancements can be added to minimise the thickness of separating barriers and control sound flanking (sound passing around a barrier) via exposed CLT elements.
  • Avoid unnecessary acoustic interventions by ensuring all advice is bespoke to the site and client brief. Invest in understanding the client’s ambitions for the project. Many acoustic issues can be mitigated by strategic planning and brief refinement at an early stage.
  • Prioritise the use of sustainable acoustic finishes. Aim to use sustainable materials and to minimise their quantity by using them efficiently.
  • Work collaboratively with other consultants to achieve solutions that work well. Valuable acoustic solutions need to be integrated into the building’s design. “Bolt-on” measures tend not to be efficient and may have unintended adverse effects.

At Peabody’s Burridge Gardens, acoustically attenuated vents were integrated into the façade design allowing dwellings to be naturally ventilated, even where they faced the railway line.

As well as considering carbon emissions, sustainable acoustic design must also seek to provide high quality acoustic environments that maximise occupant wellbeing and create spaces for people to enjoy throughout the life of the building.

Acoustics for Wellbeing

Applying the following framework to an acoustic design can help ensure the best wellbeing outcomes for our projects:

  • Approach the acoustic design through the occupant experience considering neighbours as well as the building users.
  • Engage in briefing to understand user activities and needs. Typically, an acoustic design will need to accommodate a range of activities that may require quiet, privacy, social interaction and collaboration.
  • Identify where acoustic performance should exceed the minimum regulatory standards. For example, where required to ensure good occupant experience or to future-proof the building.
  • Validate and improve the design process through post-occupancy evaluation to ensure persistent improvement in approach.

Post-occupancy evaluation of the acoustic design was undertaken at Keynsham Civic Centre, a naturally ventilated, open-plan offices with low-energy cooling.

Acoustics and Net Zero Carbon Buildings

Providing the right acoustic environment is an essential component in the design of sustainable buildings that support work, study, living, rest and recuperation.

Acoustic control can simply mean sealed, highly serviced buildings with a heavy and high embodied carbon structure. However, with the right approach, exceptional acoustics can be achieved through a passive, low-energy strategy that contributes to the design of a Net Zero Carbon building.

Successful design is highly reliant on careful clarification of the brief, collaboration between disciplines and early consideration of the acoustic strategy. The ultimate success of the design is best judged through appropriate post-occupancy evaluation.