Worked Example: Creative Agency — Timber Ceiling and Green Wall
RT60 calculation for a creative agency studio with perforated timber slat ceiling and living green wall. Shows how biophilic design elements double as acoustic treatment, achieving compliance while creating an inspiring workspace.
A 288 m³ open plan office designed to BS-8233 requires RT60 ≤ 0.6s. With Perforated timber slats on the ceiling and Green wall / living wall on walls, the calculated RT60 is 0.36s — PASS.
Room Setup
Total surface area: 333.6 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| ceiling | Perforated timber slats | 96.0 | 0.65 |
| walls-main | Painted plaster | 84.0 | 0.04 |
| walls-treatment | Green wall / living wall | 36.0 | 0.55 |
| floor | Carpet (heavy) | 96.0 | 0.30 |
| windows | Double glazing 6mm | 18.0 | 0.04 |
| door | Solid timber door | 3.6 | 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 = 12 × 8 × 3 = 288 m³
- 2
Total Surface Area
Stotal = 96.0 + 84.0 + 36.0 + 96.0 + 18.0 + 3.6 = 333.6 m²
- 3
Absorption per Surface at 500 Hz
ceiling: 96.0 m² × 0.70 = 67.20 Sabins
walls-main: 84.0 m² × 0.04 = 3.36 Sabins
walls-treatment: 36.0 m² × 0.60 = 21.60 Sabins
floor: 96.0 m² × 0.14 = 13.44 Sabins
windows: 18.0 m² × 0.04 = 0.72 Sabins
door: 3.6 m² × 0.08 = 0.29 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 67.20 + 3.36 + 21.60 + 13.44 + 0.72 + 0.29 = 106.61 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 288 / 106.61 = 0.43s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.36s. Target: ≤ 0.6s per BS-8233. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 28.8 | 67.5 | 106.6 | 137.8 | 146.4 | 138.1 |
| RT60 (s) | 1.61 | 0.69 | 0.43 | 0.34 | 0.32 | 0.34 |
| Target (s) | — | — | 0.60 | 0.60 | 0.60 | — |
| Verdict | — | — | PASS | PASS | PASS | — |
Compliance Verdict
Reference: BS 8233:2014 Table 4
Biophilic design elements — living walls and natural timber — provide genuine acoustic benefits alongside their visual and wellbeing value. The combination achieves BS 8233 compliance in a mid-sized creative studio.
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 (12m × 8m × 3m) and RT60 target (0.6s).
Open CalculatorField Story
A branding agency wants their new studio to embody their design philosophy: natural materials, living plants, and no corporate ceiling tiles. The design director commissions a perforated oak slat ceiling with acoustic backing and a 36 m² living wall of ferns and mosses on the main feature wall. Sceptics on the team question whether plants really absorb sound. The acoustic consultant's calculations confirm that the moss wall provides meaningful mid- and high-frequency absorption comparable to a commercial acoustic panel, while the perforated timber ceiling performs excellently. The space wins a design award and passes the acoustic assessment.
Frequently Asked Questions
What RT60 does a Creative Agency — Timber Ceiling and Green Wall achieve?
With the specified materials and dimensions (12m x 8m x 3m, volume 288m3), the calculated mid-frequency RT60 is 0.36s using the Sabine equation. The target under BS-8233 is 0.6s or less. The result is a PASS.
What materials are used in this office acoustic example?
This example uses Perforated timber slats on the ceiling (NRC 0.65), Painted plaster on the walls-main (NRC 0.04), Green wall / living wall on the walls-treatment (NRC 0.55), Carpet (heavy) on the floor (NRC 0.3), 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 106.6 Sabins.
How much does acoustic treatment cost for this room?
The estimated treatment cost is £17,784 for 228 m2 of absorptive material at approximately £78/m2. Actual costs vary by region, supplier, and installation complexity.
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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.