Worked Example: Care Home Lounge — Elderly Hearing-Optimised
RT60 calculation for a care home communal lounge optimised for elderly residents with hearing loss. Carpet, curtains, and acoustic ceiling create a warm domestic aesthetic while achieving the low reverberation essential for ageing ears.
A 151.2 m³ residential living designed to BS-8233 requires RT60 ≤ 0.8s. With Rockfon Sonar 25mm on the ceiling and Curtains (medium weight) on walls, the calculated RT60 is 0.28s — PASS.
Room Setup
Total surface area: 208.9 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| ceiling | Rockfon Sonar 25mm | 56.0 | 0.85 |
| walls-main | Painted plaster | 57.0 | 0.04 |
| walls-treatment | Curtains (medium weight) | 24.3 | 0.55 |
| floor | Carpet (heavy) | 56.0 | 0.30 |
| windows | Double glazing 6mm | 12.0 | 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 = 8 × 7 × 2.7 = 151.2 m³
- 2
Total Surface Area
Stotal = 56.0 + 57.0 + 24.3 + 56.0 + 12.0 + 3.6 = 208.9 m²
- 3
Absorption per Surface at 500 Hz
ceiling: 56.0 m² × 0.82 = 45.92 Sabins
walls-main: 57.0 m² × 0.04 = 2.28 Sabins
walls-treatment: 24.3 m² × 0.49 = 11.91 Sabins
floor: 56.0 m² × 0.14 = 7.84 Sabins
windows: 12.0 m² × 0.04 = 0.48 Sabins
door: 3.6 m² × 0.08 = 0.29 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 45.92 + 2.28 + 11.91 + 7.84 + 0.48 + 0.29 = 68.71 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 151.2 / 68.71 = 0.35s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.28s. Target: ≤ 0.8s per BS-8233. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 22.5 | 49.4 | 68.7 | 94.0 | 103.3 | 102.0 |
| RT60 (s) | 1.08 | 0.49 | 0.35 | 0.26 | 0.24 | 0.24 |
| Target (s) | — | — | 0.80 | 0.80 | 0.80 | — |
| Verdict | — | — | PASS | PASS | PASS | — |
Compliance Verdict
Reference: BS 8233:2014 Table 4
Care home lounges benefit from RT60 ≤ 0.8s to support residents with age-related hearing loss. Domestic-style materials (carpet, curtains) create a homely environment while providing acoustic benefit.
STI result: 0.75 (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 (8m × 7m × 2.7m) and RT60 target (0.8s).
Open CalculatorField Story
Residents at a care home increasingly eat meals in their rooms rather than the communal lounge, and staff notice that social interaction is declining. An occupational therapist identifies excessive background noise as the cause — the TV competes with conversation and the hard surfaces amplify both. Audiometric data shows that 85% of residents have moderate to severe hearing loss, requiring a signal-to-noise ratio of at least +15 dB for comfortable conversation. The care home manager invests in acoustic ceiling tiles, heavy lined curtains, and replaces the hard flooring with domestic-quality carpet. Residents gradually return to the lounge, and the activity coordinator reports a marked improvement in group participation.
Frequently Asked Questions
What RT60 does a Care Home Lounge — Elderly Hearing-Optimised achieve?
With the specified materials and dimensions (8m x 7m x 2.7m, volume 151.2m3), the calculated mid-frequency RT60 is 0.28s using the Sabine equation. The target under BS-8233 is 0.8s or less. The result is a PASS.
What materials are used in this healthcare acoustic example?
This example uses Rockfon Sonar 25mm on the ceiling (NRC 0.85), Painted plaster on the walls-main (NRC 0.04), Curtains (medium weight) 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 68.7 Sabins.
How much does acoustic treatment cost for this room?
The estimated treatment cost is £5,452 for 136 m2 of absorptive material at approximately £40/m2. Actual costs vary by region, supplier, and installation complexity.
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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.