Worked Example: GP Consulting Room — Speech Privacy Design
RT60 calculation for a GP surgery consulting room where speech privacy is critical for patient confidentiality. The small room benefits from high-NRC ceiling tiles and wall panels that reduce sound energy available to transmit through partitions.
A 37.8 m³ hospital ward designed to BS-8233 requires RT60 ≤ 0.6s. With Ecophon Focus E on the ceiling and Fabric-wrapped panel 50mm on walls, the calculated RT60 is 0.25s — PASS.
Room Setup
Total surface area: 72.3 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| ceiling | Ecophon Focus E | 14.0 | 0.90 |
| walls-main | Painted plaster | 28.5 | 0.04 |
| walls-treatment | Fabric-wrapped panel 50mm | 12.0 | 0.80 |
| floor | Vinyl/linoleum floor | 14.0 | 0.03 |
| windows | Double glazing 6mm | 2.0 | 0.04 |
| door | Solid timber door | 1.8 | 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 = 4 × 3.5 × 2.7 = 37.8 m³
- 2
Total Surface Area
Stotal = 14.0 + 28.5 + 12.0 + 14.0 + 2.0 + 1.8 = 72.3 m²
- 3
Absorption per Surface at 500 Hz
ceiling: 14.0 m² × 0.90 = 12.60 Sabins
walls-main: 28.5 m² × 0.04 = 1.14 Sabins
walls-treatment: 12.0 m² × 0.78 = 9.36 Sabins
floor: 14.0 m² × 0.03 = 0.42 Sabins
windows: 2.0 m² × 0.04 = 0.08 Sabins
door: 1.8 m² × 0.08 = 0.14 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 12.60 + 1.14 + 9.36 + 0.42 + 0.08 + 0.14 = 23.74 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 37.8 / 23.74 = 0.26s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.25s. Target: ≤ 0.6s per BS-8233. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 7.8 | 18.3 | 23.7 | 25.7 | 25.6 | 24.4 |
| RT60 (s) | 0.78 | 0.33 | 0.26 | 0.24 | 0.24 | 0.25 |
| Target (s) | — | — | 0.60 | 0.60 | 0.60 | — |
| Verdict | — | — | PASS | PASS | PASS | — |
Compliance Verdict
Reference: BS 8233:2014 Table 4; HTM 08-01
GP consulting rooms need low RT60 for both speech clarity and confidentiality. Reducing in-room reverberation lowers the sound level reaching walls, improving privacy for patients in adjacent waiting areas.
STI result: 0.81 (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 (4m × 3.5m × 2.7m) and RT60 target (0.6s).
Open CalculatorField Story
Patients at a GP surgery complain that conversations with their doctor can be overheard in the adjacent waiting room. A patient advocacy group raises the issue formally, citing GDPR concerns about medical confidentiality. The practice manager discovers that the consulting rooms have basic plasterboard ceilings with no acoustic treatment, and the partition walls only extend to the suspended ceiling grid — not the structural slab above. The acoustic consultant addresses both issues: installing Ecophon tiles and fabric wall panels to reduce in-room sound levels, and extending the partition to the slab to block flanking paths.
Frequently Asked Questions
What RT60 does a GP Consulting Room — Speech Privacy Design achieve?
With the specified materials and dimensions (4m x 3.5m x 2.7m, volume 37.8m3), the calculated mid-frequency RT60 is 0.25s 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 healthcare acoustic example?
This example uses Ecophon Focus E on the ceiling (NRC 0.9), Painted plaster on the walls-main (NRC 0.04), Fabric-wrapped panel 50mm on the walls-treatment (NRC 0.8), Vinyl/linoleum floor on the floor (NRC 0.03), 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 23.7 Sabins.
How much does acoustic treatment cost for this room?
The estimated treatment cost is £1,300 for 26 m2 of absorptive material at approximately £50/m2. Actual costs vary by region, supplier, and installation complexity.
Related Examples
Hospital Ward — BS 8233 Patient Recovery
Operating Theatre — Cleanroom Acoustic Design
Dental Surgery — Acoustic Treatment for Anxiety
MRI Suite — Patient Acoustic Comfort 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.