S06: Impact Noise Management – Above Green

(2 points)

INTENT

Reduce the level of impact noise radiation by designing resilient floors.

SUMMARY

This WELL feature requires projects to manage background noise levels by demonstrating compliance with impact noise mitigation techniques.

ISSUE

Sound can transmit between rooms within a building as structure-borne impact noise. This impact noise travels through structures (e.g., walls, floors, columns, piping) as vibrations that are then radiated as airborne noise to a listener. Typically, impact noise derives from objects impacting a floor (e.g., footfall, machinery, gym equipment) and can result in workplace distractions, sleep disturbance or disrupted focus.

SOLUTIONS

The overall construction of a building influences impact noise radiation levels. For example, a building that utilizes a light-weight floor construction (e.g., wood truss, cross-laminated timber, steel frame) generally exhibits higher degrees of impact noise radiation between floors, whereas buildings constructed with resilient, composite floor-ceiling construction (e.g., thick concrete slab, suspended ceiling, floor with an underlayment) generally exhibit lower degrees of impact noise radiation. The performance of floor-ceiling materials can be measured using the following metrics:

Impact Insulation Class rating (IIC): a lab-tested metric which is used to assess the amount of impact noise transmitted through flooring assemblies and components. The data is expressed in third-octave frequencies between 100 and 3150 Hz. A higher IIC rating indicates a greater acoustical separation from impact noise.
Normalized Impact Sound Rating (NISR): the on-site field measured metric for impact noise reduction of an entire floor-ceiling assembly. Like IIC, a higher NISR indicates a greater acoustical separation from impact noise.
Weighted Standardized Impact Sound Pressure Level (L_nTw): a metric which assesses the on-site sound pressure level of impact noise. As opposed to IIC and NISR, the lower the sound pressure level (L_nTw), the greater the acoustical separation from impact noise.

IMPACT

Increasing acoustical separation between floors can foster better environments for focus and productivity, reduce noise-related sleep disturbances and help maintain consistent, comfortable background noise levels in rooms.

REQUIREMENTS

Part 1

Specify Impact Noise Reducing Flooring (1 point)

Verified by Design Specifications

For All Spaces

The following requirement is met within the project boundary:

For the following space types, the floor-ceiling construction meets the following minimum Impact Insulation Class (IIC) ratings with materials tested in accordance with ASTM E492-09, ISO 717.2 or equivalent:

Space Type	Location of Applicable Floor-Ceiling Assembly	Minimum Impact Insulation Class (IIC)
Dwelling Units	Above	55
Fitness, Gym, Pool (if the space below is within the project boundary)	Below	50
Enclosed Office, Conference, Teleconference	Above	50
Open Workspace	Above	45
Retail, Restaurant (if the space below is within the project boundary)	Below	45

Note: L_nTw (plus modification factor Ci) may be used as an equivalent metric and equivalent values may be determined by subtracting the IIC values listed above from 110.

All projects are required to submit the WELL beta feature implementation feedback form for every WELL beta feature pursued during documentation review.

More information on WELL v2 beta features can be found at https://resources.wellcertified.com/articles/introducing-well-beta-features/.

Part 2

Meet Thresholds for Impact Noise Rating (Max: 2 points)

Verified by Professional Narrative

For All Spaces

The following requirement is met within the project boundary:

For the following space types, the floor-ceiling construction achieves the following Normalized Impact Sound Ratings (NISR), as measured on-site, in accordance with ASTM E1007-19, ISO 140-7 or equivalent, by a professional demonstrated not to have a conflict of interest:

Space Type	Location of Applicable Floor-Ceiling Assembly	Minimum NISR - 1 Point	Minimum NISR - 2 Points
Dwelling Units	Above	52	57
Fitness, Gym, Pool (if the space below is within the project boundary)	Below	47	52
Enclosed Office, Conference, Teleconference	Above	47	52
Open Workspace	Above	42	47
Retail, Restaurant (if the space below is within the project boundary)	Below	42	47

Note: On-site testing by a professional must sample at least 10% of each regularly occupied space type listed and demonstrate compliance with the minimum NISR thresholds at each test location. The professional must state in their narrative which approved reference standard was adhered to during testing (e.g., ASTM, ISO, or equivalent).

Documentation for this feature may be submitted either as part of documentation review or along with performance testing results.

L_nTw (plus modification factor Ci) may be used as an equivalent metric and equivalent values may be determined by subtracting the NISR values listed above from 110.

All projects are required to submit the WELL beta feature implementation feedback form for every WELL beta feature pursued during documentation review.

More information on WELL v2 beta features can be found at https://resources.wellcertified.com/articles/introducing-well-beta-features/.