Room acoustics modelling is most valuable at RIBA Stage 2 or early Stage 3, when the room geometry is defined but surface finish decisions are still open. Modelling at this stage allows the acoustic consultant to evaluate the proposed geometry against the performance target and specify the treatment required before the material schedule is agreed. Modelling at Stage 4 or later is possible but limits the options available to geometry-constrained treatment specification only.

Geometric acoustic models predict reverberation time with accuracy typically within plus or minus 0.1 seconds of measured values in completed buildings, provided that the absorption and scattering data used in the model is representative of the actual materials and construction. Accuracy at low frequencies below 125 Hz is reduced because geometric methods do not fully capture wave effects that dominate room acoustics in this range. For low-frequency performance, statistical or wave-based methods are used alongside the geometric model. The acoustic consultant will advise on model validity for the specific project parameters.

Yes. We build a geometric model of the existing space calibrated against in-situ reverberation time measurements, use the model to diagnose the cause of the acoustic shortfall and then test alternative treatment configurations to identify the most effective remediation option. This avoids speculative trials of acoustic treatment that may not achieve the target performance. The calibrated model also predicts the performance of the treated space, providing the client with confidence in the proposed solution before committing to the cost of installation.

For simple rectangular rooms with uniform surface finishes, a Sabine or Eyring calculation is often sufficient to confirm reverberation time and specify treatment. For rooms with complex geometry, significant volume variation, balconies, raked seating, pronounced surface clustering or critical acoustic quality requirements, a geometric model provides substantially more reliable prediction and the additional parameters, including clarity, early decay time and strength, needed for auditoria or performance space applications. The acoustic consultant will advise on which approach is appropriate for the project's complexity and performance requirements.

We require architectural drawings in sufficient detail to establish the room's three-dimensional geometry, including plan, section and elevation drawings at a stage when the ceiling geometry and principal surface areas are defined. A schedule of proposed interior surface materials, or a list of candidate materials to be evaluated, allows absorption coefficients to be assigned. Where the project has a defined acoustic performance target, whether from BB93, BREEAM, a planning condition or a client brief, we also need the relevant criteria document. Early instruction allows us to request any additional geometric information needed before the model is built.