🏫WELL v2 Feature S01 (Sound) · International

Classroom Acoustic Design to WELL v2 Feature S01 (Sound)

Classrooms are the most acoustically critical room type in education buildings, where speech intelligibility directly determines learning outcomes. A well-designed classroom achieves an unoccupied RT60 of 0.

TL;DR

Under WELL v2 Feature S01 (Sound), a classroom of 150-300 m³ (typical dimensions 10m × 7m × 3m) requires an RT60 of ≤ 0.6s at 500-2000 Hz. Background noise must not exceed 35 dBA. A minimum STI of 0.6 is required for speech intelligibility. WELL v2 Feature 74 Part 1 requires RT60 <= 0.

RT60 Target

≤ 0.6s

Noise Limit

35 dBA

STI Minimum

≥ 0.6

Frequency Range

500-2000 Hz

Specific Requirements

Parameter	Target	Clause Reference	Notes
Reverberation Time (RT60)	≤ 0.6s	S04	500-2000 Hz, Furnished, unoccupied, <500 m³
Background Noise Limit	≤ 30 NC	S01 Part 2	HVAC + building services, unoccupied
Speech Transmission Index (STI)	≥ 0.6	—	Per IEC 60268-16:2020
Frequency Range	500-2000 Hz	—	Octave bands for compliance assessment

Step-by-Step Compliance Calculation

1
Review WELL Feature 74 requirements
Identify which parts (1-3) apply to the classroom space within the WELL project boundary.
2
Set acoustic targets
RT60 <= 0.6s, background noise <= 35 dBA, STI >= 0.60 at all occupied positions.
3
Design treatment package
Specify ceiling, wall, and floor treatments to meet RT60 and STI targets simultaneously.
4
Coordinate with MEP engineer
Ensure HVAC design meets 35 dBA noise criterion with appropriate duct attenuation and diffuser selection.
5
Arrange third-party testing
Engage a WELL-approved acoustic consultant to conduct post-construction verification measurements.

Recommended Materials

Surface	Material Category	Min NRC	Coverage %
Ceiling	Mineral wool ceiling tile	0.85	80%
Rear wall	Acoustic panel	0.80	40%
Floor	Carpet tile	0.25	100%

Browse the full acoustic materials database for absorption coefficients and product specifications.

Common Failure Modes

⚠️Third-party verification failure

WELL requires independent acoustic testing. Design-stage predictions that marginally meet targets often fail field verification.

⚠️HVAC noise in green buildings

Energy-efficient HVAC systems with variable speed drives can produce tonal noise that exceeds 35 dBA criteria.

Frequently Asked Questions

What RT60 does WELL v2 Feature S01 (Sound) require for a classroom?

WELL v2 Feature S01 (Sound) requires a reverberation time of ≤0.6s at 500-2000 Hz for classroom spaces. WELL v2 Feature 74 Part 1 requires RT60 <= 0.6s in classrooms within WELL-certified buildings. Background noise from HVAC must not exceed 35 dBA. STI of 0.60 or higher is expected for occupied learning environments. Third-party acoustic verification is required for certification.

What is the maximum background noise level for a classroom under WELL v2 Feature S01 (Sound)?

WELL v2 Feature S01 (Sound) sets a maximum background noise level of 35 dBA for classroom spaces. This includes noise from HVAC systems, building services, and external intrusion, measured with the room unoccupied. Exceeding this limit degrades speech intelligibility and occupant comfort.

How much acoustic treatment does a classroom need to comply with WELL v2 Feature S01 (Sound)?

A typical classroom (150-300 m³) requires Mineral wool ceiling tile (NRC ≥0.85) covering 80% of the ceiling as the primary treatment. Additional wall absorption on 2 surface(s) is typically needed. Use the AcousPlan calculator with the pre-loaded dimensions (9m × 7m × 3m) to calculate the exact absorption deficit for your room.

Calculate WELL v2 Feature S01 (Sound) Compliance for Your Classroom

Pre-loaded with typical classroom dimensions (9m × 7m × 3m) and an RT60 target of 0.6s per WELL v2 Feature S01 (Sound). Enter your actual dimensions, select materials, and verify compliance instantly.

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