Acoustic fabrics in public spaces: technical guide for architects

9-min read — Updated December 2025

Acoustic comfort has become an architectural quality criterion on a par with natural light or thermal performance. In a restaurant, a hotel lobby, an open-space or a meeting room, the reverberation time determines occupants' ability to communicate, concentrate or rest. Acoustic textiles are one of the most powerful levers to address this topic — and one of the most poorly mastered in briefs.

This article provides architects and design offices with the technical vocabulary, specification criteria and reference budgets to correctly integrate acoustic fabrics into an office, hospitality or public-body project.

1. Space acoustics: the 3 quantities every architect must know

Reverberation time (RT or T₆₀)

Time needed for a sound to decay by 60 dB after the source stops. An RT of 0.4 s is comfortable for speech; beyond 0.8 s, comprehension in a restaurant becomes difficult; at 1.5 s, an open-space becomes hostile to concentration.

Absorption coefficient α (alpha)

Measures, between 0 and 1, the ability of a material to absorb acoustic energy. Bare concrete wall: α ≈ 0.05. Thick carpet: α ≈ 0.35. Acoustic fabric stretched over rock wool: α ≈ 0.85-0.95. The closer α is to 1, the more the material "sucks in" the sound.

Weighted absorption coefficient αw

This is the single, standardised (ISO 11654) value that summarises absorption performance over a spectrum of typical speech frequencies (125 Hz to 4 kHz). This is the figure to specify first in a CCTP. For a fabric stretched on an acoustic support in office spaces, target αw ≥ 0.85.

Absorption classes

To simplify specification, the EN ISO 11654 standard defines 5 classes:

Class	αw	Performance
A	0.90 - 1.00	Very strongly absorbing
B	0.80 - 0.85	Strongly absorbing
C	0.60 - 0.75	Medium absorbing
D	0.30 - 0.55	Weakly absorbing
E	0.15 - 0.25	Very weakly absorbing

2. The 4 acoustic-fabric typologies in public spaces

Typology 1 — Hung acoustic curtain

Thick fabric (300-550 g/m²) with a looped or multi-layer structure. Used as a movable partition, space divider, or window curtain in noisy areas.

Performance: αw = 0.40 to 0.70 depending on weight, distance to wall, pleating. Note: a curtain pressed against a hard wall absorbs significantly less than one leaving 8-15 cm of clear space behind (air cavity = acoustic resonance absorbed).

Applications: street-facing restaurant windows, movable ballroom dividers, acoustic stage curtains, textile partitions in open-spaces.

Typology 2 — Stretched acoustic textile panel

Peripheral frame (aluminium or wood) on which a thin fabric (150-220 g/m²) is stretched in front of an absorbent core (40 kg/m³ rock wool, melamine foam, wood wool). Total thickness 30-60 mm.

Performance: αw = 0.80 to 0.95 depending on core thickness and distance to support wall. This is the highest-performing technical solution per m² for an office space.

Applications: open-space walls, meeting-room partitions, acoustic suspended ceilings, hotel corridors, break areas.

Typology 3 — Suspended textile baffle and island

3D textile volume suspended from the ceiling, absorbing on all faces. Maximum efficiency in environments with high clear ceiling (> 3.5 m).

Performance: αw (equivalent sabin) = 0.70 to 0.90 depending on density and volume. The physical principle differs from surface α — we talk about equivalent absorption surface per object.

Applications: reception halls, dining spaces, amphitheatres, open-spaces with technical ceilings.

Typology 4 — Carpet and textile floor coverings

Thick tufted carpet (> 6 mm pile), on absorbing underlay. Contribution to overall room absorption, especially for mid-high frequencies.

Performance: αw = 0.20 to 0.40 depending on pile type and underlay. Complementary role — rarely sufficient alone.

3. Quick calculation rule: what do you need for your project?

Simplified formula (Sabine) to estimate the volume of absorption required:

A (in m² sabin) = 0.161 × V / target RT Where V = room volume in m³ and RT = target reverberation time in seconds.

Example — 200 m² restaurant, 3.20 m ceiling

V = 200 × 3.2 = 640 m³. Target RT for conversational comfort: 0.6 s. Required absorption: A = 0.161 × 640 / 0.6 ≈ 172 m² sabin.

With acoustic textile panels αw = 0.90, about 190 m² of walls or ceiling must be covered to reach the target. In practice, distribute: 30% ceiling, 40% wall panels, 20% window curtains, 10% carpet.

Example — 120 m² hotel lobby, 4.50 m ceiling

V = 120 × 4.5 = 540 m³. Target RT: 0.8 s (welcoming lounge). A ≈ 109 m² sabin. Solution: 5 × 1.2 × 2 m suspended baffles + 40 m² of textile wall panels.

4. How to specify correctly in a CCTP

The right words to put in writing:

« Supply and installation of acoustic textile panels measuring 1200 × 600 mm, 40 mm thick. Structure: rock-wool core 40 kg/m³ density, facing fabric stretched on peripheral aluminium frame. Fabric fire rating: M1 (NF P 92-503) or equivalent B-s1,d0. Acoustic performance: class A per ISO 11654, αw ≥ 0.85, attested by a notified laboratory test report. Wall fixing via concealed hooks. The contractor shall provide: acoustic test report, fabric fire test report, frame data sheet, installation and maintenance notice. »

Common mistakes to avoid:

• Writing "absorbing fabric" without specifying αw: each supplier interprets it differently.
• Not specifying core thickness: even with identical fabric, a 20 mm panel and a 50 mm panel have very different performances.
• Forgetting the facing-fabric fire rating: the panel can be acoustic and not M1 fire-rated — prohibited in ERP.
• Specifying total absorption without distributing between walls, ceiling, floor — which prevents the supplier from sizing.

5. 2026 budgets by typology

Solution	Budget excl. VAT/m² installed	Typical αw
Standard textile wall panel	€180-280 excl. VAT/m²	0.85-0.90
Printed textile panel (custom visual)	€280-450 excl. VAT/m²	0.80-0.90
Stretched acoustic textile ceiling	€150-240 excl. VAT/m²	0.75-0.90
Suspended baffle (per equivalent m²)	€220-380 excl. VAT/m²	0.75-0.90
Heavy acoustic curtain (window)	€140-280 excl. VAT/m²	0.40-0.65

6. The 5 most expensive mistakes on an acoustic project

1. Diagnosing after delivery: a prior acoustic study costs €1,500-4,000 excl. VAT. A post-delivery fix costs 10 to 50 times more. Do the study at the design-stage APD, not after the opening.
2. Neglecting residual hard surfaces: treating only ceilings in a restaurant with glass walls and polished-concrete floor gives a mediocre result. Acoustics is a distribution topic, not a "single zone" topic.
3. Choosing an aesthetic non-acoustic fabric: some very pretty fabrics are acoustically transparent but do not let sound pass through correctly to the absorbing core. Always ask for the acoustic test report of the complete system, not just the fabric.
4. Underestimating the distance to the wall: an acoustic panel glued directly to the wall absorbs 20-40% less than one offset by 20 mm (air-cavity resonance). Plan a fixing system that respects this space.
5. Not planning for maintenance: an acoustic fabric gets dirty, retains dust, gradually loses its efficiency (−5 to −15% in 5 years without care). Plan an annual dusting and a professional cleaning every 3 years.

FAQ — Textile acoustic specification for architects

Can an architect do without an acoustician?

For a project < 150 m² with simple geometry, yes, using the Sabine formula and manufacturers that provide test reports. Beyond that, or with strong constraints (concert halls, ballrooms, studios), an acoustician is mandatory to model the diffuse field.

Are all acoustic fabrics fire-retardant?

No. Some decorative acoustic fabrics are not fire-rated. In ERP, always require a combined acoustic + M1 test report.

Can an acoustic fabric be painted?

Not recommended. Paint clogs the micro-porosities and strongly degrades acoustic performance (−30 to −60%). If a colour effect is sought: use bath-dyed fabrics, not surface-painted ones.

What lifespan for a textile acoustic panel?

15-20 years in office interiors, 10-15 years in restaurants (grease, historical passive smoking). The rock-wool core does not age; it is the facing fabric that gets replaced every 8-12 years.

Acoustic absorption and acoustic insulation: the same thing?

No, two distinct topics. Insulation = preventing sound from passing between two rooms (wall, partition, double glazing). Absorption = reducing reverberation in the same room (textile, ceiling, coverings). The two must be treated separately.

In summary

A well-designed textile acoustic project rests on 4 levers: measure/estimate the existing reverberation time, set a target RT adapted to use, calculate the required absorption via Sabine, distribute intelligently between wall panels, ceiling, curtains and floor coverings. Specifying rigorously in the CCTP (αw, absorption class, core thickness, fire rating) eliminates 80% of delivered performance gaps.

For an architect, acoustic textile is today one of the finest levers combining measurable performance, aesthetic impact and creative latitude (formats, colours, digital printing). Provided it is handled at the design-stage APD, not as a "catch-up" after delivery.