Worked Example: Kindergarten Playroom — DIN 18041 Acoustic Design
RT60 calculation for a German kindergarten playroom using acoustic plaster ceiling instead of suspended tiles. Demonstrates how seamless acoustic plaster achieves compliance while being robust enough for active play environments.
A 240 m³ classroom designed to DIN-18041 requires RT60 ≤ 0.6s. With Acoustic plaster 15mm on the ceiling and Fabric-wrapped panel 50mm on walls, the calculated RT60 is 0.45s — PASS.
Room Setup
Total surface area: 288.0 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| ceiling | Acoustic plaster 15mm | 80.0 | 0.70 |
| walls-main | Painted plaster | 94.0 | 0.04 |
| walls-treatment | Fabric-wrapped panel 50mm | 14.0 | 0.80 |
| floor | Rubber sport floor | 80.0 | 0.08 |
| windows | Double glazing 6mm | 16.0 | 0.04 |
| door | Solid timber door | 4.0 | 0.08 |
Absorption coefficients sourced from manufacturer datasheets and ISO 354 test reports. Browse the full acoustic materials database.
Step-by-Step Calculation
- 1
Room Volume
V = L × W × H = 10 × 8 × 3 = 240 m³
- 2
Total Surface Area
Stotal = 80.0 + 94.0 + 14.0 + 80.0 + 16.0 + 4.0 = 288.0 m²
- 3
Absorption per Surface at 500 Hz
ceiling: 80.0 m² × 0.65 = 52.00 Sabins
walls-main: 94.0 m² × 0.04 = 3.76 Sabins
walls-treatment: 14.0 m² × 0.78 = 10.92 Sabins
floor: 80.0 m² × 0.08 = 6.40 Sabins
windows: 16.0 m² × 0.04 = 0.64 Sabins
door: 4.0 m² × 0.08 = 0.32 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 52.00 + 3.76 + 10.92 + 6.40 + 0.64 + 0.32 = 74.04 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 240 / 74.04 = 0.52s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.45s. Target: 0.4--0.6s per DIN-18041. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 17.2 | 42.7 | 74.0 | 91.0 | 93.9 | 85.2 |
| RT60 (s) | 2.25 | 0.91 | 0.52 | 0.42 | 0.41 | 0.45 |
| Target (s) | — | — | 0.60 | 0.60 | 0.60 | — |
| Verdict | — | — | PASS | PASS | PASS | — |
Compliance Verdict
Reference: DIN 18041:2016 Table 1
DIN 18041 classifies kindergarten playrooms as Group A (speech communication). Acoustic plaster provides a seamless, robust ceiling finish suitable for environments where suspended tiles risk damage from ball games.
STI result: 0.66 (per IEC 60268-16:2020)
Cost Estimate
Costs are indicative and vary by region, supplier, and installation complexity. For a detailed cost breakdown, use the AcousPlan calculator.
Open the AcousPlan calculator pre-loaded with the exact room dimensions (10m × 8m × 3m) and RT60 target (0.6s).
Open CalculatorField Story
Staff at a Munich Kindergarten report that children's excited play creates overwhelming noise levels that leave educators exhausted by noon. The playroom has a hard plaster ceiling, tiled walls, and a rubber floor — necessary for hygiene and durability but acoustically terrible. Suspended ceiling tiles were tried previously but children threw balls into them, causing constant breakage. The acoustic consultant specifies a spray-applied acoustic plaster directly onto the existing ceiling — providing NRC 0.70 absorption with a seamless, indestructible finish that looks like a conventional plastered ceiling.
Frequently Asked Questions
What RT60 does a Kindergarten Playroom — DIN 18041 Acoustic Design achieve?
With the specified materials and dimensions (10m x 8m x 3m, volume 240m3), the calculated mid-frequency RT60 is 0.45s using the Sabine equation. The target under DIN-18041 is 0.4--0.6s. The result is a PASS.
What materials are used in this education acoustic example?
This example uses Acoustic plaster 15mm on the ceiling (NRC 0.7), Painted plaster on the walls-main (NRC 0.04), Fabric-wrapped panel 50mm on the walls-treatment (NRC 0.8), Rubber sport floor on the floor (NRC 0.08), Double glazing 6mm on the windows (NRC 0.04), Solid timber door on the door (NRC 0.08). The total absorption at 500 Hz is 74.0 Sabins.
How much does acoustic treatment cost for this room?
The estimated treatment cost is €6,110 for 94 m2 of absorptive material at approximately €65/m2. Actual costs vary by region, supplier, and installation complexity.
Related Examples
UK Primary Classroom — BB93 Acoustic Compliance
UK Secondary Classroom — BB93 Marginal Result
US Classroom — ANSI S12.60 Acoustic Compliance
German Classroom — DIN 18041 Acoustic Design
Explore More
All calculations are advisory and based on the Sabine equation (ISO 3382-2:2008 Annex A). Results require professional verification for compliance submissions. Absorption coefficients are sourced from manufacturer datasheets and ISO 354 test reports.