Acoustic Refurbishment & Fit-Out

E-mail: pod@space-pod.net

Tel: 01628 535 790

Image of soundproof rehearsal pods at ACM Guildford

So how do we soundproof a room or office, well basically we don’t!

We do however construct and modify rooms to isolate sound, whether it be airborne or impact vibration. We design recording studios, production suites, practice rooms, pods and dance environments. All have differing acoustic requirements and differing ways of dealing with sound transfer.

During an acoustic refurbishment project we spend a lot of time constructing these spaces to a high acoustic standard isolating area to area and minimising sound transfer between adjacent spaces. We effectively build rooms within rooms, isolating each layer by means of decoupling techniques and effective use of air gaps with obsessive detailing of sealing any air transfer gaps between layers and cavities.

This obsessive attention detailing applies to walls, floors and ceilings/roofs and we design solutions that incorporate all 3 elements together as a whole relative to your building to ensure that the joints between each element perform correctly and eliminate sound transfer at junctions.

The most critical points in the design are nearly always penetrations through the walls, including door sets, windows and services.

  • We design door solutions that realise a 40–45 dB sound reduction using acoustic seals and acoustic bars. However, this isn’t always enough to attenuate the room sufficiently and we will often also install a double door set to provide further sound reduction.
  • We design acoustic windows in a variety of sizes and specifications depending on the required usage, with each window being designed to perform in accordance with the adjacent wall and door specifications. This can range from straight forward double glazed isolated floating units for dance studios through to sophisticated high isolation units featuring two sets of double glazing with various weights of glass at differing angles with neoprene isolation bars giving a sound reduction of 65-75 dB.
  • Special attention is paid to services with electrical, fresh air, air-con all dealt with specifically with a variety of techniques to ensure any penetrations into the rooms maintain the integrity of the structure and do not allow sound leakage around the penetrations.
  • Further attenuation covers sound transfer through pipe and duct work with isolation fixings utilised to prevent vibration transfer.
  • Fire alarms are dealt with specifically utilising the same techniques as the electrics to ensure minimal sound leakage with special attention placed on locations of sounders/lights/beacons and system interlocks to ensure minimal delay to egress in the event of the fire alarm being activated.
  • Further tuning of the spaces can be provided utilising acoustic absorption/diffusion panels and bass traps to ensure the rooms perform correctly.
Picture of an acoustically sound-proof window

A guide to office acoustics

Basic acoustics

• Good acoustics are essential to productivity and creativity in the workplace. Indeed they can be key to the success of a building.
• Acoustic problems and disturbance in a room are often derived from either long reverberation times, which give a room an echoey feel or from noises outside the room and poor sound insulation.
• Sound is a series of waves or pressure fluctuations, which start with an object vibrating. It moves or propagates in the air from its source at about 1,200km/h or 786mph.
• As it travels the sound dissipates. If it hits a hard surface it can reflect the reflection can lead to a build-up of sound energy. If it hits a soft surface some of the energy can be absorbed. As the sound encounters objects such as walls the energy passing through them is reduced.
• When sound travels through air it is described as airborne; when it moves through a solid it is termed structure borne.
• Sound is measured in terms of the frequency of the wave, expressed in hertz (Hz), and the wavelength and pressure level, expressed in decibels (dB).
• Decibels are a logarithmic scale, and are best described using typical noises: shouting (80dBA), a pneumatic drill (100dBA). Sound levels above 120dBA would be the threshold for pain in most humans.
We perceive an increase of 10dBA as a doubling of sound.
• Reduction figures of 10dB are describing a perceived reduction of 50% or 20dB being a reduction of 75%. Humans can detect a difference of about 3dB.
• To communicate effectively, normal speech needs to be between 10dB and 15dB above the background noise level.

Acoustic control

• Sound can be controlled in three distinct ways:
1) Absorption, which deals with reverberation within the space.
2) Insulation (attenuation), which deals with the control of sound from one space to another.
3) Diffusion, which scatters the sound.
• Sound reflects in a similar way to light.
• The acoustic quality of a room can be expressed by measuring the reverberation time (RT). If a room has a long reverberation time, one spoken word does not have time to die out before the next reaches the listener.
• In order to reduce reverberation times, sound absorbing products such as ceilings, rafts, wall panels, carpets and free standing structures can be introduced.
• The sound absorption coefficients of a particular material are expressed as αw – 0.0 being no absorbency and 1.0 being 100%. For ease of comparison, manufacturers
categorise products using five performance bands, A to E, where A denotes the highest absorption.
• A products sound insulation performance is expressed as a weighted sound reduction index described as Rw in accordance with BS EN ISO 717-1: 1997.
• If office background noise is too high, productivity is likely to suffer. If background noise is too low, privacy can suffer.
• Research has shown that ceilings have the biggest impact on the acoustic quality of open plan offices.
• The sound insulation performance of the ceiling may be compromised when it is penetrated by lighting fixtures and ventilation ducting grilles.
• Sound can also be transmitted through building elements, this is known as flanking which can be defined as sound travelling around a sound resisting element.
• When installing acoustic performance partitioning it should be made as airtight as possible.
• Wall sockets should not be installed back to back.

Design considerations

• When selecting the performance rating of a partition, background noise levels need to be taken into account. BS 8233: 1999 encourages the principle of acoustic zoning, using the concepts of intrusive noise and privacy factors. Background sound can provide vital masking.
• The cumulative effect of different building elements will affect the overall room to room performance.
• The speech privacy potential (SPP) combines the partition sound insulation performance expressed in terms of installed R’w with the background noise level in the receiving room expressed in terms of NR. The higher the resulting SPP, the higher the level of privacy
between the rooms.
• Speech intelligibility defines the degree of privacy in a space. The higher the intelligibility, the better for promoting communication in a space; the lower it is, the better for privacy. Intelligibility is affected by the background noise level and reverberant characteristics of a space.

Source: Association of Interior Specialists

Image of a team working in an open-plan office
Picture of Steelcase Kalidro Office Desk Systems

Acoustics - What to consider when planning an office fit out

Type of space
Atria, open plan, rest area, restaurant etc.
Communication generally important.

Deployment considerations
Where privacy is important ensure that a speech transmission index of ≤0.4 can be achieved between adjacent areas.
The suspended ceiling will provide the greatest effect on absorption in a space.
Consider absorbent baffles on the walls or ceiling to absorb and diffuse sound.
Consider installing ceiling rafts and islands to increase absorption where exposed soffits are used.
Consider lowering the ceiling between work clusters.

Other considerations
Too much absorption can make a space unnaturally dead.
Too little will mean long reverberation times, leading to increased sound levels as people raise voices to be heard over sound that has not decayed.

Outset considerations common to both sound absorption and sound insulation.

Zone the space, putting areas of communication in the quietest part of the building, and areas of privacy with higher levels of background noise.

Determine the acoustic requirement of the space.
Understand the background noise of the space from all external and internal sources.
Establish suitable reverberation times and noise levels for the space.
The size, including height, shape and internal finishes will affect the acoustic properties of the space: ensure these are taken into account.
Consider the services of an acoustician.
Remember that sound insulation affects users in adjacent spaces, while sound absorption affects the quality of the sound in the space.
Understand the effect on acoustics if an exposed soffit is used, as the lack of an absorbent ceiling could result in increased reverberant noise level or the lowering of background noise where mechanical ventilation is absent.

Deployment considerations

When looking at test data, check that the test data is still relevant, and ask to see the whole report detailing the composition and assembly of the system.

Ensure that the products are installed fully in accordance with the manufacturer’s method of build .
Consider additional absorption in areas of highly reflective surfaces, such as glass or polished plaster.

Other considerations

Be prepared to carry out additional works to fine tune the space in use.

image of foam wall sound dampening panels
Image of a man in an open-plan office, wearing headphones because of inadequate sound-proofing

Steps required for sound insulation

Type of space

Meeting room, conference room, cellular space etc.
Privacy generally important.

Deployment considerations
Consider planning offices and meeting areas where background sound (e.g. from ventilation or office activity) can mask conversation and assist in privacy.
Where communication is important ensure that a speech transmission index of ≥0.6 can be achieved within the communication zone.
Look at the sound insulation requirements separately to sound absorption, i.e. partitions, doors, floors.
Where privacy is important ensure that the partition can achieve the required Dnf,w / Dw by specifying the insulating factors of all the elements separately from sound absorption.
When considering the insulating value of partitioning, understand that an onsite test Dnf,w / Dw will be lower to the laboratory test of Rw by between 3-8dB dependant on the partition type (e.g. lightweight stud or blockwork).
Consider the effect of flanking paths above ceilings or building services.
Balance the benefit of flexibility afforded by installing partitioning to the underside of the suspended ceiling (with appropriate cavity barriers in place) against additional performance but with additional cost and disruption should the partition need moving.

Other considerations
Too much absorption can make a space unnaturally dead.
Too little will mean long reverberation times, leading to increased sound levels as people raise voices to be heard over sound that has not decayed.

Mezzanine Floors

Having purchased or leased your premises, why not maximise your internal volume by installing a mezzanine floor?

adding space with mezzanine floors

CHURN Refurbishment

‘Out of hours office churn’ means moving, re-fitting or relocating occupied offices at a time when they’re not being used.

we can restructure your office over a weekend

Collaborative Workspaces

Collaborative working can speed up productivity and the generation of new ideas.

reconnect the disconnected workplace

Space Planning

The right use of space can make as much impact on your business as the right choice of people.

how productive is your office space?

Accreditations

Space-pod accepts our responsibility to work safely, cleanly and in a way which is caring to our staff, our customers, our community and the environment.

We have introduced a number of initiatives designed to continuously improve our quality, health & safety and environmental performance, to ensure that our staff are safe and give our customers confidence and peace-of-mind that we will act responsibly at all times. READ MORE >