Assessment & Treatment Protocol
A fixed sequence, not a checklist applied loosely - each step depends on the one before it, from first site visit to signed-off result.
Site Survey & Measurement. On-site acoustic survey - reverberation time (RT60) and impulse response measured to ISO 3382, background noise levels assessed against Portugal's RRAE thresholds - establishing the actual problem before proposing a fix.
Material & Treatment Modeling. Absorption coefficients (tested to ISO 354 and expressed as NRC) and diffusion coefficients matched to the frequencies identified in the survey, modeled against the reverberation time targets set out in DIN 18041 for the room's intended use, before any material is ordered.
Installation Sequencing. Structural isolation goes in first, then surface treatment, then fine-tuning - installed in the order that avoids redoing earlier work.
Verification & Sign-off. Post-installation measurement, re-run to the same ISO 3382 and RRAE criteria used at survey stage, confirms the targets were met - documented and handed over to the client.
What Portuguese Law Requires
Acoustic treatment for a commercial space in Portugal isn't just a design choice - it has to clear specific legal thresholds before a venue can operate. These are the regulations every project gets checked against.
General Noise Regulation - Decree-Law 9/2007 (RGR)
Sets the ambient noise limits a venue's activity can't exceed at the property line: 55 dB by day / 45 dB at night in residential areas, 65 dB by day / 55 dB at night in commercial areas. Live music inside a restaurant or bar requires a special noise licence (licença especial de ruído) from the local council.
Building Acoustic Requirements - Decree-Law 96/2008 (RRAE)
Sets minimum airborne sound insulation between adjoining units - at least 50 dB - plus separate requirements for impact noise, façades, and mechanical equipment, extended to hotel units, auditoriums, and performance spaces.