sound / acoustic comfort / healthy building

acoustical comfort in healthy buildings

Acoustical comfort or what the WELL healthy building standard calls ‘acoustic performance’ is a core concept for healthy building standards and wellbeing interiors, yet is often a forgotten piece of the interior architecture puzzle, especially when designing offices for example.

Acoustics, sound and its unwanted cousin ‘noise’ are therefore an essential building block of occupant comfort and Indoor Environmental Quality (IEQ), alongside thermal comfort, adequate lighting and Indoor Air Quality (IAQ). Typically here we are working with sound mapping, spatial layouts, acoustic thresholds and criteria for optimal performance, sound masking and soundscapes. When in doubt, we call in an expert acoustics consultant!

The WELL healthy building rating standard has an entire Sound chapter dedicated to acoustics. We interviewed the Sound Concept Lead for our podcast here, sound acoustician Ethan Bourdeau based in New York. The Pre—Condition for this section is a spatial layout breaking a space down into different zones, for example in a biophilic office space we might identify quiet zones for deep work and privacy, mixed zones for informal meetings and loud zones for collaboration, coffee breaks and so on.

There are then a series of additional Credits for Maximum Noise Levels; Sound Barriers; Sound Absorption; Sound Masking; Impact Noise Management; Enhanced Audio Devices and Hearing Health Conservation.

Use of acoustic partition walls and doors, combined with other sound absorbing materials in an office, study space or residence all help ensure adequate acoustical comfort for building occupants. By installing acoustic panels overhead, high performance glass partition walls and acoustic flooring solutions we can significantly reduce the Reverberation Time (RT) - the amount of time a sound lingers - in an interior space. These are the main levers we have as healthy building consultants considering acoustics.

More tactical yet equally worthwhile solutions include the introduction of acoustical wall treatments, acoustic wall panels, acoustic desk dividers, reliable door gaskets and acoustic light fixtures. It’s about making a series of small but meaningful interventions. All such sound reducing surfaces are an Optimization in the WELL healthy building standard Sound Concept.

Sound wellness is a relatively new concept but one that has evolutionary roots, as with so much in the field of healthy buildings, wellbeing interiors and biophilic design in particular. It is based on sound therapy in which soundscapes are used to trigger emotions within us to help illicit a certain emotional state of mental clarity, allowing us to step back from the realities of life in a mindful moment, no matter how brief.

Natural soundscapes or ‘biophilic sounds’ have a role to play in creating restorative spaces such as recharge rooms aimed at restoring a sense of zen calm, for example in a high-energy workplace. This can often be equated to the sonic experience of ‘forest bathing’ whereby we are actively engaged in listening to the natural sounds around us whilst in a remote nature spot. These can also be an example of an active acoustic treatment, a.k.a ‘sound masking’ to create consistent noise levels and increase sound privacy, while decreasing acoustic distractions.

What sources should we as healthy building consultants be particularly aware of in an office building or residential development? Design oversights such as loud HVAC equipment, improperly insulated spaces, and the omission of sound mapping in the design phase could all create acousti issues post-occupancy. If a CrossFit gym moves into the ground floor of a mixed-use building, that too will quickly become an issue unless they install suitable sound absorbing gym flooring tiles!

Generally enclosed spaces dominated by hard interior surfaces such as ceramic floors and metal tables cause sound to literally bounce around, or reverberate from one surface to the next. A building in use is going to generate noise from occupant’s voices, footfall in corridors and so on. Planning for this early on in the healthy building design phase is a far more efficient strategy than trying to fix the acoustical issue later on.

What tools do we have as healthy building consultants to minimize unwanted noise and maximize acoustic comfort in an office or residential development? Early on there is the opportunity to isolate HVAC systems, working in collaboration with the project engineer. In terms of wellbeing interior spaces, we focus more on the strategic use of acoustic, sound absorbing materials, be that in the ceiling, floor, wall treatments or partitions and doors.

From there, if the issue has not significantly improved, we can consider introducing consistent ‘white noise’ or ‘pink noise’ as a sound masking strategy. In some circumstances, such as an executive office conference room where speech intelligibility is especially important, we may integrate high performance audio technology such as speech enhancement technology to provide maximum occupant comfort.

What are the negative impacts of unwanted noise in a building interior? Primarily, attention levels are badly hit, which in turn impacts focus, productivity and memory retention, soon becoming a source of low level stress as it is repeated over time and accumulates greater damage.

If noise levels are too high in a space that is being used for quiet, reflective thinking, there is a fundamental mismatch between the acoustic environment and the use requirements of that space. This is what we want to avoid as healthy building consultants.

The dimensions and intended usage of a particular space as well as the expected demographics of its users help us as healthy building consultants to identify potential acoustic issues. By creating different zones within an interior space and overlaying that with possible sources of noise, be that mechanical such as a whirring HVAC system, or occupant generated such as footfall in a corridor, we can identify possible pain points in terms of acoustical performance for a building interior. This type of Sound Mapping is an essential ‘Precondition’ in the WELL healthy building rating system’s Sound Concept.