A common modern office layout would be an open plan central space for the majority of workers, with separate offices around the edge for key team members, and perhaps some meeting rooms. A key consideration when planning this kind of layout is noise.
There are several noise-related questions that need answering as part of the specification process:
- Will unwanted noise from the central work space disturb the people in the offices?
- Will noise from within the offices distract those in neighbouring spaces?
- Do any of the offices need privacy?
Glass partitions looks great, and are easy to install and move if a reconfiguration is ever needed. But do they really have the soundproofing properties needed to ensure that everyone can work distraction-free, and have private conversations if needed?
How is soundproofing measured?
One figure you may see quoted in relation to acoustics is an Rw value from the sound reduction index. This is a value of sound reduction performance, within a lab environment. It can be helpful to compare options. For example, single glazed 12mm partition is around 32Rw. 12mm double glazed with an acoustic laminate can achieve up to 49Rw.
However, it’s perhaps more useful to relate this to speech privacy level – that’s what the weighted sound reduction index does. Based on this index, a measure of 45 dB means loud speech can be heard faintly, but not distinguished. This is a sufficient level of soundproofing for most office situations.
However, there are a couple of other aspects which need to be taken into consideration. There’s something called flanking transmission – that’s how things like junctions between partitions and around things like air conditioning ducts affect the actual performance in situ (as opposed to in the lab environment). With the very best team on the case, you can still expect to lose up to 5dB on the weighted sound reduction index value. It’s important to take this into account at the planning stage – that 5dB can make the difference between loud speech being distinguished or not.
So, there’s another value – Dw, which is the weighted sound level difference on site.
There’s also the issue of background noise, which helps mask sound transmission in the real world. This is measured in dBA and is usually between 40 and 50 dBA. This figure is added to the Dw value to give another number known as the Speech Privacy Potential (SPP).
A good SPP figure to aim for, where privacy is important, would be 85dBA – this means that loud speech is barely audible and is unintelligible.
Whilst this provides a great starting point for specifying a glass partition, it still doesn’t take into account things like the positioning of the office. So, as you can see, it’s not a simple calculation. That’s where working with an expert really pays off!
Acoustic performance of double-glazed partition
Our double-glazed partitions reduce the level of speech intelligibility and reduce distracting noise coming in. This is sufficient for most offices. Our Polar Double Glazed Partitioning, for example, has a rating of 49dB on the sound reduction index.
Our specialist acoustic glass
Whilst double glazing is sufficient for most office environments, there are some specialist environments, such as pharmaceutical laboratories and media centres, that need a greater level of acoustic insulation. That’s where our specialist acoustic glass comes in. With an additional laminate in place, the travel of sound is reduced to almost nothing.
Don’t forget the doors
By their very natures, the join between a door and the surrounding partition has the potential to reduce the acoustic performance. However, there have been some great advances in door sealing technology, enabling them to achieve good acoustic performance. Our Sonik acoustic double glazed door, for example, achieves acoustics up to 38dB.
Ask the experts
As you can see, when it comes to acoustic performance, there are a lot of measurements to take into consideration. Getting this step right can make the difference between an office environment that really works and some awkward conversations in the future!
If you have a project in Norfolk, Suffolk, Essex, Cambridgeshire or London, one of our team will be happy to come and visit you on-site to help advise on the best solution for you. Get in touch to book an appointment.