The LEED mission, as stated in the Strategic Plan, is to ensure that buildings create spaces that promote human and environmental well-being, including designing healthier and safer environments for building occupants. Therefore, we believe that the acoustic requirements need to be reconsidered in the new 5th LEED version, aligning them more closely with LEED’s mission.
Acoustic comfort in the new version will become less relevant than in the previous version 4.1, as it loses its specific place within the "Indoor Environmental Quality" category, becoming a sub-item ("Sound Environment") within the "Occupant Experience" item. This applies to both "Commercial Interiors" (LEED ID+C) and "New Construction" (LEED BD+C) certifications, categories that include developments such as offices, hotels, or healthcare and educational facilities.
Another point is that in some types of developments such as offices, hotels, or hospitals, the acoustic comfort, which was worth 2 credits in version 4.1, now only counts for 1 credit in version 5, out of the 7 credits in the "Occupant Experience" item.
In LEED 4.1, there was an EQ Credit: Acoustic Performance that applied to both BD+C (New constructions, schools, data centers, distribution centers, and lodging, worth 1 point, and healthcare facilities worth 2 points) as well as to ID+C (offices and lodging, worth 2 points). To obtain the credit, three criteria had to be met:
a) Air conditioning noise, meeting the sound levels established in Table 1 of chapter 48 of the ASHRAE Handbook HVAC Applications, for each type of environment.
b) Sound transmission (STC or NIC),
c) Reverberation time (T60).
For the new LEED version 5, there is no "Acoustic Performance" credit, but within EQ Occupant Experience, there is an option called "Sound Environment" worth 1 point, proposing the development of an acoustic plan mapping the different acoustic zones of the project, classifying them by type of use (noisy zone, quiet zone, mixed zone, circulation, or not applicable). Another requirement is that acoustic solutions are defined with a focus on managing acoustic comfort, background noise, privacy, reverberation time and impact noise, but without any objective requirements.
It also considers:
- Minimizing the effect of external noise (traffic, aircraft, railways, or building equipment) on building occupants;
- Treating sound transmission between noisy and quiet zones;
- Achieving a noise level for air conditioning equipment of maximum 35dBA in areas for speech, conferences, or learning.
As advantages, we see that on the other hand, LEED version 5 starts to consider relevant aspects for acoustics such as impact noise insulation or building envelope insulation from external noise, which were not considered in version 4.1.
But, on the other hand, it seems that in the new LEED version 5, we encounter the following negative points compared to version 4.1:
- Acoustic comfort no longer constitutes a specific credit and its score decreases.
- There are no criteria for acoustic insulation, reverberation time, or background noise that allow evaluating if the project is meeting the requirements, but rather simply proposes making an acoustic plan, which seems too vague and open when it comes to conducting an objective assessment of acoustic comfort.
Furthermore, offering a choice between meeting the requirements for Sound Environment and the requirements for Thermal Environment, for example, does not guarantee a genuinely healthy space. It is essential to recognize that the technical requirements for thermal studies cannot be replaced by acoustic studies, as they are complementary and not equivalent.
Given this, we request a reassessment of the items related to acoustics in LEED v5.
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Kevin Packer
May 17, 2024 - 6:25 pm
I am disappointed with the proposed changes. In the province of Alberta where I practice all new publicly funded K-12 schools need to achieve LEED silver as a minimum and the acoustic prerequisites in LEED v4 help to ensure that at least HVAC background noise and reverberation control are considered in the designs for the core learning spaces. The schools must also be designed to meet the acoustic requirements in the Alberta Technical Design Requirements, and these are fairly robust, but the threat of not achieving LEED certification if acoustics are ignored carries a lot of weight.
The optional LEED acoustic credits in v4 are more difficult to navigate and achieve but these could have been improved and clarified rather than totally replacing them with more generic/subjective requirements.
Judging from the available v5 pdf BD+C and ID+C documents, the proposed v5 standards seem much more generic, not project type specific as in v4.1 (e.g. schools, health care, etc.).
LEED seem to be trying to align these with the WELL precondition acoustic requirements. The WELL acoustic optimizations are more robust.
Good acoustics are important to quality of life and moving away from at least some basic measurable prerequisite acoustic criteria and to more open ended/subjective criteria seems like a step backwards.
It would be good to hear from someone involved with the development of the LEED acoustic requirements/credits for more context on these changes.
Chris Mackey
Co-FounderLadybug Tools LLC
1 thumbs up
May 18, 2024 - 3:34 pm
I second the comments here.
Sound privacy is arguably the aspect of the indoor environment that surveyed occupants are most dissatisfied with. Noise level is not too far behind it and they are both responsible for far more dissatisfaction than “visual comfort” and “amount of light.” This large study conducted at the CBE confirms that.
The fact that there is only one credit here but 4 for lighting is just a clear indication of misplaced priorities. Not that lighting doesn't also need attention and credits.
Granted, I am not really an expert on acoustics so my recommendations might not be much more than adding a credit for performing acoustic simulation. But I know that there are a lot of missed opportunities with this credit category and you really should be talking to experts to improve it.