Why open-space booms — reverberation time in practice
Reverberation is sound that keeps bouncing between hard surfaces after the source has stopped. It is measured as RT60 — the number of seconds it takes the sound level to drop by 60 dB. In a typical office with a smooth slab, glass and a tiled floor, RT60 reaches 1.2–1.5 s: a conversation at the next desk is audible throughout the room, and every phone call makes the next person raise their voice. The target for open-space is below 0.8 s, for conference and meeting rooms below 0.6 s.
The largest reflecting surface in an office is the ceiling — which is why it gives the most when it changes from reflecting to absorbing. Wall panels and carpets help, but they will not replace several dozen square metres of absorption overhead.
How a tensioned acoustic ceiling works
The membrane is micro-perforated — thousands of openings per square metre, invisible from floor level. The sound wave passes through the perforation into the space above the ceiling, where the absorber (a layer of sound-absorbing material) turns its energy into heat. To the room, the membrane presents a smooth, uniform plane — no tile grid, no visible panels. The absorption achieved reaches Class A, which in practice means up to 75% less reverberation compared with a bare slab.
The material is A2-class polyester — non-combustible, which in office and public buildings is a requirement, not an option. Installation is cold, without a heat gun: no odour, no raised temperature, and the electronics and server rooms next door are safe.
Three ways to tackle reverberation — a comparison
Each solution makes sense in a different situation. The table sets them out honestly, including when a stretch ceiling is not the best choice.
| Criterion | Wall panels | Drywall + mineral wool | Tensioned acoustic ceiling |
|---|---|---|---|
| Effectiveness | limited by wall area | good, but unperforated board reflects | up to Class A across the whole ceiling |
| Installation time (100 m²) | 1–2 days | 1–2 weeks with skim coat and painting | 2–3 days, weekends possible |
| Disruption to office work | minor | dust, noise, zone shut down | no dust, installation outside working hours |
| Removability | yes | no — demolition | yes — membrane comes down, profiles stay |
| Access to services | n/a | inspection hatches | through the removable membrane |
| When to choose | as a supplement, small rooms | when the ceiling must also insulate | open-space, meeting rooms, restaurants — when effect and time matter |
What it costs and how the schedule looks
The rate for a tensioned acoustic ceiling is from around 320 PLN/m² net installed, typically 320–450 PLN/m² depending on geometry, the number of cut-outs for fittings and sensors, and the required absorption class. At the scale of a 100 m² office the unit rate drops towards the bottom of the range: a realistic cost is around 32,000–38,000 PLN net. Any additional absorption in the space above the membrane is quoted after a reverberation measurement, because it depends on the room volume and the existing slab.
Schedule: measurement and a reverberation measurement on site, made-to-measure membrane production, installation in 2–3 working days. For working offices we plan the work outside office hours or at the weekend — the crew comes in on Friday afternoon, and on Monday morning the office works under its new ceiling. Furniture and workstations stay; it is enough to move them away from the walls. Payment is a 30% deposit and 70% within 7 days after installation; the quote is valid for 30 days.
What we check at the measurement and what we need from the client
Before quoting we measure the reverberation time as it stands — that is the reference point against which we compare the result after installation. We check the height, the services above the ceiling (air conditioning, sprinklers, cabling), the layout of fittings and sensors, because every cut-out is planned at the membrane production stage. From the client we need the lighting design, or a decision on which fittings stay, and information on the building's fire-safety requirements — we attach the material classification to the documentation.
If the office already has a suspended tile ceiling, we install the membrane below it or in place of the tiles — the height decides, and whether the existing structure is to remain. We carry out projects of this kind for hotels and restaurants as well; one example is the Candor project in Sint-Martens-Latem, Belgium, which you will find among our case studies.