Open plan offices now make up approximately 75% of all office workplaces in the UK. These areas feature reduced division between employees in the space. The popularity of these types of offices is nothing new. They’ve now become the preferred layout for most types of businesses to promote collaboration and communication. They can also contribute to the culture of the workplace by bringing people closer together. Up until recently there were no open plan office acoustics standards which guided designers to ensure the benefits of open offices are fully realised. In offices where they can be 20+ individuals all working in the same space, noise can be an issue.

This article will analyse aspects of the BS ISO 22955:2021 to give a guideline on the types of acoustic treatments are recommended and that Resonics can provide for your space.

The effects of noise in open plan offices

Noises that are uncontrollable, intelligible or have no relevance to your current activity are deemed to be the most disturbing. Distractions are everywhere in open plan offices. With multiple sources of noise pollution, operating at ranging frequencies, it can become quite the uncomfortable place to be. Uncomfortable employees are unproductive, as their concentration is heavily effective. With appropriate and mindful office design and effective acoustic treatment, the negatives of open plan working can be reduced significantly.

For more info regarding the effects of noise in offices, and the pros and cons of open working, read our other article on the topic.

Here we will focus more on the guidelines for meeting the new standards for open plan office acoustics.

The approach

The goal is to limit disturbances and distractions between desks and workstations but optimise quality of short distance converstations. Acceptable noise levels can varydepending on the tasks and work being undertaken.

The standard outlines 6 types of spaces, the acoustic challenges of which all sync around intelligibility and discretion. But here we will focus on general guidelines surrounding the acoustic treatment methods that are suitable for most open plan offices.

Guidelines for Open Plan Office Acoustics

Acoustic treatment involves applying sound absorbing materials to hard surfaces to limit sound reflection, echo and reverberation. Without treatment, noise levels reach uncomfortable levels as sounds continue to ping off hard surfaces multiple times without anything to absorb this sound. Room acoustic treatment generally will consist of;

1.Ceiling Treatment

Acoustic ceiling treatment is, as the name suggests, solutions which are installed to the ceiling to absorb reverberation and noise within the space. They are particularly effective in large, open plan spaces as they are often the surface which has the most exposed area. Ceilings also generally are hard surfaces, which results in the sound bouncing directly back into the area below increasing the overall noise in the office.

According to the new BS ISO 22955:2021, the ceiling is the most important treatment area, and should feature approximately 50-60% coverage in open plan office spaces. The standard also mentions that products with an absorption coefficient of close to 1 should be used. This means products that are Class A absorbers such as Ecophon Solo, SilentSpace Rafts and Autex Horizon. Ceiling baffles can also be used in certain situations.

acoustic-ceiling-treatment

Acoustic Ceiling Rafts

2.Wall Treatment

Wall surfaces are usually much smaller in comparison to the ceiling in open plan work areas, but wall treatment can also be effective. While not as important as ceiling treatment, the use of Acoustic Wall panels or stretched fabric systems can be especially effective in corner areas of the office. These systems are important for work stations which directly face or are close to walls, and especially in corner areas of open plan spaces. In these corners, sound will travel off both wall surfaces, creating flutter echo. Ideal height for wall treatments is at least 1.2 metres.

While no specific recommendations are given by the standard, our team will be able to recommend wall treatments in your space where required.

wall treatment

Acoustic Wall Panels

3.Floor Treatment

Floor treatment offers limited general absorption and is not significant enough to make improvements to the acoustics on its own. Coverings with acoustic interlayers can assist with mid to high frequency absorption on the floor. The main benefit is simply to reduce impact noise of people walking through the office. We focus on Ceiling and Wall treatments as they are the most effective solutions to solve the issues in your office.

 

Other considerations for open plan office acoustics

Acoustic Furniture

We have seen an influx of ‘Acoustic Furniture’ hitting the market in recent years. In general, furniture will not be significant to absorb sound and solve acoustic issues – surface treatment should be prioritised. However, provided the ceiling is appropriately treated, acoustic furniture which has actual acoustic value can make an improvement to the reverberation levels within the office. It can be used as a substitute for wall treatments in certain applications.

Acoustic Screens & Desk Screens

Screens can be used in the form of desk mounted screens or suspended acoustic screens which can be used to create divisions within the work spaces. For desk screens, having high enough to interrupt the path of speech from one desk to another is recommend. Higher than mouth height! Acoustic screens generally don’t provide adequate performance to reduce or replace the need for ceiling or wall treatments. Screen performance will be assessed in relation to absorption and attenuation.

Sound Masking 

Sound masking systems have come under scrutiny in open plan offices, with some finding in counter productive. This product essentially is added noise to a space to ‘mask’ existing ambient noise from services, phones and other general environmental noise. Noise from ventilation, heating, air conditioning etc is sometimes misused or substituted for proper sound masking installations. However, these sounds usually do not operate in the correct frequencies and levels to properly mask noise.  Products such as SoftdB are designed to operate and adjust to the existing ambient noise. The use of sound masking should be considered during design and activities to be undertaken within the office.

Our surveying team will be able to recommend the right systems for your office.

Conclusion

This new standard gives clear advice on requirements for acoustic treatment in open work spaces. We will work with you to ensure that your office meets the standards, and productivity is optimised for your team.

Contact Resonics to chat about your next project.