Greetings,
The relevant table.1 (minimum composite sound transmission class ratings or noise isolation class for adjacent spaces) in this Acoustic Performance Credit requires minimum sound insulation values to be met for separating constructions between acoustically rated rooms. However, the credit does not specify whether the criteria can be relaxed if there is a door within the separating construction.
If the Credit wording is read as-is, it is suggesting that, for example phone booths (assumed as ‘confidential’ spaces in the table) adjacent to open plan workstation areas (collaborative / multi-use) require a 50dB doorset, as the area of the separating construction will be comprised mostly of the door.
This is impractical for office spaces, as it will likely require heavyweight specialist acoustic doorsets similar to what is found in recording studios.
Can anyone please clarify this matter and how to best approach it in a practical way.
Many Thanks.
- Is the use of the phone room truly “confidential”, or would it be sufficient if classified as “private”? In our experience a private classification is suitable for most enclosed space types including phone rooms, unless there are healthcare or legal information considerations based on the type of client.
- While we haven't seen the layout of the space you're dealing with, it's worth considering the distance between phone room and workstation areas. Is there a sizeable circulation/corridor/hallway zone between the two? The credit table calls for a lower criteria at "hallways", and in our experience, distance across circulation zones shouldn't necessarily be written off.
- Take note of the double asterisk at the bottom of the criteria table, which advises STC/NIC criteria may be lowered by 5 points if a sound masking system is implemented at a minimum level of 40 dBA.
With a sound masking system introduced and/or the adjacency classification adjusted, the criteria is then reduced by 5-10 points or more. There are more options to achieve NIC-35 to NIC-40 performance with a well-gasketed, insulated core swing door; this performance does not implicitly require the aforementioned specialty door. -Adam