This is a legacy version of the WELL Building Standard. Please check the latest version here.
  1. Comfort
  2. Reverberation time

Reverberation time

Features>Comfort>78. Reverberation time

78. Reverberation time

Intent: 

To help maintain comfortable sound levels by limiting reverberation times.

Reverberation time, or RT60, is a metric which describes the length of time taken for a sound to decay by 60 dB from its original level. Optimal reverberation times vary depending on room volume, intended use of the space and the frequency of transmitted sound. In spaces with high reverberation times, the sounds of voices and footsteps take longer to dissipate, contributing to higher levels of ambient noise. The noise produced by reverberation can decrease speech intelligibility and in some situations cause additional stress. This performance specification can be met through the use of sound-absorbing materials on various surface and design elements.

Part 1: Reverberation Time

The following spaces have maximum reverberation time (RT60) as described:

a.90 Conference rooms: 0.6 seconds.
b. Open workspaces: 0.5 seconds.
Part 2: Reverberation Time for Learning Spaces

Reverberation time measurements for learning spaces meet the following criteria:

a.133 Spaces less than or equal to 3,000 m³ [10,000 ft³]: less than 0.6 seconds.
b.133 Spaces greater than 3,000 m³ [10,000 ft³] and equal to or less than 6,000 m³ [20,000 ft³] : less than 0.7 seconds.
Endocrine
Cardiovascular
Nervous

Applicability Matrix

Core & Shell New & Existing Buildings New & Existing Interiors
Part 1: Reverberation Time - O O
Commercial Kitchen Education Multifamily Residential Restaurant Retail
Part 2: Reverberation Time for Learning Spaces - O - - -

Verification Methods Matrix

Letters of Assurance Annotated Documents On-Site Checks
Part 1: Reverberation Time Performance Test
Part 2: Reverberation Time for Learning Spaces Performance Test

90

U.S. General Services Administration Center for Workplace Strategy Public Buildings Service. Sound Matters: How to Achieve Acoustic Comfort in the Contemporary Office. Washington, D.C.: 2012: 11, 29, 32, 33, 36.
78.1.a

The General Services Administration's Sound Matters recommends RT60 of 0.6 seconds for meeting rooms.
133

Accredited Standards Committee, S12 Noise. ANSI/ASA S12.60-2010/Part 1 American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, Part 1: Permanent Schools. Melville, NY: Acoustical Society of America; 2010:8-10.
78.2.a

ANSI/ASA S12.60-2010 Part 1 recommends maximum permitted reverberation times for core learning spaces of less than or equal to 10,000 ft³ to be 0.6 seconds.
78.2.b

ANSI/ASA S12.60-2010 Part 1 recommends maximum permitted reverberation times for core learning spaces greater than 10,000 ft³ and equal to or less than 20,000 ft³ to be 0.7 seconds.
Features>Comfort>78. Reverberation time