Worked Example: Student Housing Room — BB93/Part E Compliance
18 m³ student bedroom with concrete block walls, vinyl floor, and minimal furnishing
A 18 m³ residential living designed to BB93 requires RT60 ≤ 0.5s. With Painted plaster on the ceiling, the calculated RT60 is 0.61s — FAIL.
Room Setup
Total surface area: 45.6 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| Ceiling | Painted plaster | 9.0 | 0.04 |
| Floor | Vinyl/linoleum floor | 9.0 | 0.04 |
| Walls — painted concrete | Painted concrete block | 16.0 | 0.07 |
| Walls — plasterboard | Plasterboard on studs | 4.0 | 0.07 |
| Curtain | Curtains (medium weight) | 2.0 | 0.56 |
| Bed + mattress | Upholstered seating | 2.0 | 0.55 |
| Window | Double glazing 6mm | 2.0 | 0.03 |
| Door | Solid timber door | 1.6 | 0.09 |
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 = 3 × 3 × 2 = 18 m³
- 2
Total Surface Area
Stotal = 9.0 + 9.0 + 16.0 + 4.0 + 2.0 + 2.0 + 2.0 + 1.6 = 45.6 m²
- 3
Absorption per Surface at 500 Hz
Ceiling: 9.0 m² × 0.04 = 0.36 Sabins
Floor: 9.0 m² × 0.03 = 0.27 Sabins
Walls — painted concrete: 16.0 m² × 0.06 = 0.96 Sabins
Walls — plasterboard: 4.0 m² × 0.05 = 0.20 Sabins
Curtain: 2.0 m² × 0.49 = 0.98 Sabins
Bed + mattress: 2.0 m² × 0.56 = 1.12 Sabins
Window: 2.0 m² × 0.04 = 0.08 Sabins
Door: 1.6 m² × 0.08 = 0.13 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 0.36 + 0.27 + 0.96 + 0.20 + 0.98 + 1.12 + 0.08 + 0.13 = 4.10 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 18 / 4.10 = 0.71s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.61s. Target: 0.3--0.5s per BB93. Verdict: FAIL
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 4.1 | 3.3 | 4.1 | 5.1 | 5.3 | 5.1 |
| RT60 (s) | 0.71 | 0.89 | 0.71 | 0.57 | 0.54 | 0.57 |
| Target (s) | — | — | 0.50 | 0.50 | 0.50 | — |
| Verdict | — | — | FAIL | MARGINAL | MARGINAL | — |
Compliance Verdict
Reference:
Open the AcousPlan calculator pre-loaded with the exact room dimensions (3m × 3m × 2m) and RT60 target (0.5s).
Open CalculatorField Story
A university in Manchester is building a 500-room student residence using CLT construction. Each 3 m by 3 m study bedroom features painted concrete block party walls for fire separation. The vinyl floor is the developer default for durability between academic years. The room is assessed in "arrival condition" — before the student brings rugs and posters — representing worst-case acoustics. Only the bed mattress, thin curtain, and door provide meaningful absorption. BB93 and Approved Document E govern sound insulation between rooms, but internal reverberation amplifies noise breakin through the party wall. This calculation demonstrates why student housing receives noise complaints: minimum-specification creates a reverberant environment that STC-rated walls cannot compensate for without internal absorption.
Frequently Asked Questions
What RT60 does a Student Housing Room — BB93/Part E Compliance achieve?
With the specified materials and dimensions (3m x 3m x 2m, volume 18m3), the calculated mid-frequency RT60 is 0.61s using the Sabine equation. The target under BB93 is 0.3--0.5s. The result is a FAIL.
What materials are used in this residential acoustic example?
This example uses Painted plaster on the Ceiling (NRC 0.04), Vinyl/linoleum floor on the Floor (NRC 0.04), Painted concrete block on the Walls — painted concrete (NRC 0.07), Plasterboard on studs on the Walls — plasterboard (NRC 0.07), Curtains (medium weight) on the Curtain (NRC 0.56), Upholstered seating on the Bed + mattress (NRC 0.55), Double glazing 6mm on the Window (NRC 0.03), Solid timber door on the Door (NRC 0.09). The total absorption at 500 Hz is 4.1 Sabins.
How much does acoustic treatment cost for this room?
Cost data is not available for this example. Use the AcousPlan calculator to estimate treatment costs for your specific room configuration.
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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.