For the quantity surveyor and the finance side
The business case for designed sound
This argument lands with finance rather than with a designer or a wellbeing team. A commissioned background sound level can allow a floor to reach its speech-privacy target with a lighter isolation specification, which is a capital trade a quantity surveyor can model. Here is how to put a number on it for your project.
The mechanism, in short
Privacy is a ratio, not a wall
Speech privacy is the ratio between the speech that carries and the background it is heard against. Partitions, glazing and absorption work on the first half of that ratio. A designed, commissioned background sound level works on the second, alongside them, so the isolation the acoustician has to specify may come down: partition ratings, meeting-room glazing, full-height walls. It offsets isolation, not absorption, and it only counts when it is commissioned to a specified level.
How to model it
Six steps a QS can run
Set the privacy target by zone
Agree the required privacy outcome for each space with your acoustician, and how it will be measured, rather than setting one target for the floor as a whole.
Design the background sound level per zone
WELL S06 gives usable, defensible bands: 40 to 45 dBA across open work areas, and the narrower 40 to 42 dBA in focus rooms. The point is holding the level, not just reaching it.
Re-derive the isolation at that background
Ask your acoustician for the isolation needed to hit the privacy target at the raised background, rather than against the background the project would otherwise have assumed. The difference against the proposed acoustic design is the change that assessment permits. Step 04 establishes whether it saves money.
Cost the isolation delta
Partition ratings, meeting-room glazing specification, wall build-ups, door and glazing seals, ceiling sealing, and, where the acoustician confirms it and the design team and client agree, the number of enclosed rooms, which serve purposes beyond speech privacy. Cost only the changes the acoustician has approved, and only where every required performance is retained. This is the gross saving.
Compare upfront and ongoing costs
Subtract the installed and commissioned system cost from the construction saving to get the net upfront difference. Then set the subscription, maintenance, energy and replacement costs against it over the evaluation period your project uses. We quote both parts for your floor, and both numbers are yours to check.
Assess the value at reconfiguration
Where the equipment still suits the new plan, a later fitout can retain and rezone it rather than buy it again. Allow for the acoustic reassessment, any relocation and the recommissioning, then compare that against replacing the system. Treat it as a possible future benefit, held separately from the upfront number.
Assess the listening experience alongside the cost
The finance case, without giving up the room
Conventional fixed-spectrum masking makes this same capital argument. Its spectrum is set at commissioning and its material never varies. Compare the two on the same privacy targets, the same commissioning requirement and the same evaluation period, so the financial comparison is like for like.
Designed soundscaping makes the identical capital argument and adds nature-derived content, generative rather than a repeating playlist, and adaptive to occupancy and time of day. Both approaches can contribute to S06, which sets background sound requirements. Judge the difference by listening to it, and by the research, alongside the acoustic specification.
So the finance case does not cost you the experience case. The business case should answer both: whether the system is worth what it costs, and whether the sound suits the people who will hear it all day.
Model it on your project
Send us the floor plan and the privacy targets
Send a floor plan and the speech-privacy targets your acoustician is working to. We will map the zones, propose the background sound levels, and give you the system cost to net against any construction changes your project team confirms.
This document is deliberately not gated. Forward it to whoever signs the fitout budget. If it is useful, that is the point.