Meeting room acoustics: Rw thresholds, sound insulation, confidentiality. Kytom method, costs per m², lead times and ROI measured across 1,200+ office projects.
"Voices carry in the hallways"
An unusable room means 8 to 12 hours per week of meetings relocated elsewhere. For a 20 m² room rented at 450 euros excl. VAT/m²/year in Paris, the occupancy cost climbs to 9,000 euros/year for marginal use. <a href="https://www.arseg.asso.fr/" rel="noopener" target="_blank">ARSEG</a> estimates the average rate of underused rooms due to acoustic discomfort at 15%.
Noise ranks among the top three causes of cognitive fatigue in the office. Prolonged exposure above 55 dB(A) in a meeting reduces measured concentration by 20%. For a project manager, this risk weighs on the quality of decisions made in committee and on reported absenteeism.
The regulations require protection against disruptive noise in work spaces (articles R4214-1 and R4213-5). In the office sector, the expected acoustic thresholds correspond to an Rw greater than or equal to 44 dB for a confidential room. A GDPR audit may also identify a sound leak as a security flaw for the data being exchanged.
Kytom addresses acoustics along two complementary lines: insulation (what gets out) and correction (what resonates inside). Our partner acousticians measure the Rw sound reduction index of existing partitions, then size a calibrated response: 98/48 partitions lined with rock wool to reach Rw 48 dB, suspended ceilings rated Class A, wall-mounted absorbent panels targeting vocal frequencies (500 to 2,000 Hz). Over an average treated surface of 850 m², we aim for a reverberation time below 0.6 seconds. Present across 11 branches in France and Spain, our account managers coordinate the acoustician, electrician and drywall installer to meet an average lead time of 12 weeks, without interrupting the operation of neighbouring floors.
On-site measurement of the DnT,A insulation between rooms and the TR60 reverberation time. Mapping of sound leaks (doors, ducts, plenum). Deliverable: a quantified acoustic report compared against the regulatory thresholds applicable to office spaces, with prioritisation of the 3 to 5 critical points per audited room.
Definition of the target confidentiality level by room type (board room, video, creativity) and budget trade-offs with the project manager. Validation of a quantified objective: target Rw, target TR60, STI intelligibility index. Deliverable: a signed framing note and an estimated budget per m².
Detailed technical plans for partitions, ceilings, wall treatments and acoustic joinery (brush-seal doors, 44.2/16/44.2 glazing). Selection of certified materials (acoustic test reports, M1 fire rating). Deliverable: a complete tender package, an execution schedule over 10 to 14 weeks and coordination of the trades.
Execution by our integrated teams, intermediate checks on the singular points (junctions, penetrations). Acceptance acoustic measurement compared against the contractual objectives. Deliverable: an acoustic acceptance report, a digital as-built file and a performance guarantee over 24 months.
"Our strategic committee meetings were held with the door closed but in a low voice. After the works, we regained normal use of the board room, and the complaints stopped within six weeks."
For a board room or HR room, target Rw ≥ 48 dB on partitions and 35 dB on the door. The reference thresholds for high-confidentiality spaces are 44 dB minimum at the standard level and 50 dB at the performance level.
An acoustic lining gains 8 to 12 dB on an existing partition, which is sufficient in 60% of cases. Beyond that, rebuilding in 98/48 with double rock-wool facing remains more economical over 850 m² than stacking successive linings.
Three solutions: extend the partitions up to the top slab (ideal), apply acoustic flocking over 1.2 m on each side, or install 100 mm mineral-wool plenum baffles. Additional cost of 35 to 80 euros excl. VAT per linear metre.
Yes. The video-conferencing objective is correction, not just insulation. Aim for a TR60 between 0.4 and 0.5 seconds with absorbent panels covering 40% of the wall surfaces and a Class A ceiling to ensure an STI intelligibility above 0.75.
Yes, in 90% of our projects. The noisy phases (removal, drilling) are scheduled in the evening or at weekends. The dry phases (panel and ceiling installation) are done during the day with temporary partitioning. Lead time extended by 2 to 3 weeks on average.
Kytom contracts the Rw and TR60 objectives into the agreement, with an acceptance measurement by an independent acoustician. A 24-month performance guarantee covers any discrepancies, with rectification at our expense if the contractual thresholds are not met.