Worked Example: Garden Room Studio — Best Practice Home Recording
25 m³ garden office with mineral wool ceiling, fabric panels, foam, and carpet
A 25 m³ recording studio designed to ISO-3382 requires RT60 ≤ 0.4s. With Mineral wool 50mm (wall) on the ceiling and Fabric-wrapped panel 50mm on walls, the calculated RT60 is 0.18s — MARGINAL.
Room Setup
Total surface area: 55.6 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| Ceiling — mineral wool | Mineral wool 50mm (wall) | 10.0 | 0.73 |
| Ceiling — plasterboard | Plasterboard on studs | 2.5 | 0.07 |
| Floor | Heavy carpet | 12.5 | 0.29 |
| Walls — plasterboard | Plasterboard on studs | 12.0 | 0.07 |
| Walls — fabric panel | Fabric-wrapped panel 50mm | 6.0 | 0.78 |
| Walls — acoustic foam | Acoustic foam 50mm | 6.0 | 0.63 |
| Window | Double glazing 6mm | 3.0 | 0.03 |
| Walls — painted plaster | Painted plaster | 2.0 | 0.04 |
| 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 = 5 × 2.5 × 2 = 25 m³
- 2
Total Surface Area
Stotal = 10.0 + 2.5 + 12.5 + 12.0 + 6.0 + 6.0 + 3.0 + 2.0 + 1.6 = 55.6 m²
- 3
Absorption per Surface at 500 Hz
Ceiling — mineral wool: 10.0 m² × 0.70 = 7.00 Sabins
Ceiling — plasterboard: 2.5 m² × 0.05 = 0.13 Sabins
Floor: 12.5 m² × 0.14 = 1.75 Sabins
Walls — plasterboard: 12.0 m² × 0.05 = 0.60 Sabins
Walls — fabric panel: 6.0 m² × 0.78 = 4.68 Sabins
Walls — acoustic foam: 6.0 m² × 0.55 = 3.30 Sabins
Window: 3.0 m² × 0.04 = 0.12 Sabins
Walls — painted plaster: 2.0 m² × 0.04 = 0.08 Sabins
Door: 1.6 m² × 0.08 = 0.13 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 7.00 + 0.13 + 1.75 + 0.60 + 4.68 + 3.30 + 0.12 + 0.08 + 0.13 = 17.79 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 25 / 17.79 = 0.23s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.18s. Target: 0.2--0.4s per ISO-3382. Verdict: MARGINAL
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 8.0 | 12.2 | 17.8 | 23.9 | 28.6 | 29.5 |
| RT60 (s) | 0.50 | 0.33 | 0.23 | 0.17 | 0.14 | 0.14 |
| Target (s) | — | — | 0.40 | 0.40 | 0.40 | — |
| Verdict | — | — | PASS | MARGINAL | FAIL | — |
Compliance Verdict
Reference:
Open the AcousPlan calculator pre-loaded with the exact room dimensions (5m × 2.5m × 2m) and RT60 target (0.4s).
Open CalculatorField Story
A voiceover artist in rural Devon has installed a prefabricated garden room as a dedicated recording studio separate from family noise. The 5 m by 2.5 m insulated timber-frame structure uses 50 mm mineral wool behind a perforated fabric ceiling as the primary broadband absorber. Fabric-wrapped panels on the wall behind the microphone target first reflections colouring the recorded voice. Acoustic foam on the opposite wall prevents flutter echo between parallel short walls. Heavy carpet absorbs footfall and chair movement picked up by the condenser microphone. The double-glazed window and solid-core door provide thermal insulation and sound isolation from garden birds and neighbours. Best practice for voiceover recording targets RT60 below 0.4 s for clean, dry recordings that clients can add ambience to in post-production.
Frequently Asked Questions
What RT60 does a Garden Room Studio — Best Practice Home Recording achieve?
With the specified materials and dimensions (5m x 2.5m x 2m, volume 25m3), the calculated mid-frequency RT60 is 0.18s using the Sabine equation. The target under ISO-3382 is 0.2--0.4s. The result is a MARGINAL.
What materials are used in this residential acoustic example?
This example uses Mineral wool 50mm (wall) on the Ceiling — mineral wool (NRC 0.73), Plasterboard on studs on the Ceiling — plasterboard (NRC 0.07), Heavy carpet on the Floor (NRC 0.29), Plasterboard on studs on the Walls — plasterboard (NRC 0.07), Fabric-wrapped panel 50mm on the Walls — fabric panel (NRC 0.78), Acoustic foam 50mm on the Walls — acoustic foam (NRC 0.63), Double glazing 6mm on the Window (NRC 0.03), Painted plaster on the Walls — painted plaster (NRC 0.04), Solid timber door on the Door (NRC 0.09). The total absorption at 500 Hz is 17.8 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.
Related Examples
Living Room — BS 8233 Residential Comfort
Home Cinema — THX Reference Standard Design
Office Podcast Studio — Recording Booth Design
Recording Studio Control Room — EBU Standard
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.