“48 dB insulation” is incomplete unless it identifies what is measured. In B2B procurement, performance needs an element or building, an indicator, a method and test conditions. Airtightness requires the same documentary care.
Do not interchange laboratory and site performance
Rw describes laboratory performance of an element. Room-to-room and façade insulation use different indicators in Spain’s DB HR. Joints, ventilation openings and transmission through adjacent elements can change the finished result. A good glazing datasheet does not automatically establish whole-home sound insulation.
Our commissioning recommendation is to identify the noise source, receiving room and project requirement. The report should show which construction was tested and whether it matches the installed one. Acoustic ratings cannot simply be added layer by layer.
An air test also needs context
As an arithmetic example, a reference volume of 70 m³ with leakage flow of 42 m³/h at 50 Pa gives 0.6 h⁻¹. This explains n50; it does not demonstrate that a particular capsule achieves it or has certification. Volume, preparation, method and instruments must be recorded.
Suggested quality process
- Test a representative prototype before advertising performance.
- Document seals, windows, junctions and service penetrations.
- Schedule checks that locate defects before finishes are closed.
- Record remedial work and verify its effect.
Ventilation and comfort should be designed alongside the envelope. One measurement cannot replace system design. References here concern Spanish projects.
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Sources and scope
Sources reviewed 11 October 2026. Handover and control lists are CasasCápsula editorial recommendations; they do not replace project calculations, tests or documents.