Sustainable Acoustic Office Design
Our client was a Local Authority, and the project below concerns its brand-new office accommodation.
The overall project had ‘sustainability’, high on its agenda and in order to complete these ambitious aims it utilised BREEAM (Building Research Establishment Environmental Assessment Method). Relevant BREEAM acoustic credits deal with the sound insulation between rooms and other occupied areas and the indoor ambient noise levels in such rooms.
Numerous research studies have found that as well as noise levels inhibiting productivity and communication, excessive noise in the workplace has a direct effect on well-being. A 2008 review[1] assessed many articles and studies carried out which involved the effects of open plan offices and found that ‘noise is a dominant disturbing force in the open plan office environment which leads to poor employee satisfaction, lower morale, decreased productivity, increased stress levels, increased absenteeism and overall increased staff turnover’.
To facilitate avoiding such productivity issues associated with open-plan offices, the project architects in conjunction with the end user opted to provide a design solution where only cellular offices were to form the final design solution (158 cellular offices to be precise) with occupancies in each ranging from 1 to 4 people.
Finch’s extensive architectural acoustics expertise was sought to provide design solutions for the various party wall solutions separating the cellular rooms including junction details, detailing of ceiling void barriers, service penetrations, entrance door acoustic performance and layout design etc. Our advice resulted in the design team adopting to utilise a solution comprising “thin” party wall construction which spans from slab to slab thus maximizing commercial lettable floor space.
To provide maximum control to the occupants of the offices, rather than utilising a centralised ventilation system for the supply and extraction of air, the designers opted for individual mechanical ventilation heat recovery (MVHR) systems, located inside the ceiling void above the offices. In addition to this, the ceiling voids included the typical Fan Coil Units (FCU) for improved comfort cooling or heating. This design solution created an acoustics challenge due to the numerous noise sources in the ceiling void (with mesh ceiling located extract grilles). Industry technologies previously solved the associated challenges with the noise contribution from FCUs in the preceding decades by introducing the “real room” offsite test methods. However, no relevant information existed in order for the designers to provide a desktop assessment of the likely internal noise levels based on the bespoke and unique design proposed for this scheme. Due to the significant risk of noncompliance with the BREEAM requirements (a contractual obligation for the contractor), a solution had to be found in order to facilitate the contractor to better manage the risk associated with failures during the pre-completion testing (another subsequent requirement in BREEAM).
As such, Finch’s acousticians used their extensive knowledge to expedite and design a bespoke test arrangement and provide suitable sound power limits that would ensure project compliance with such requirements. As part of our involvement, we were tasked to contact various testing facilities (where in the past we have witnessed numerous “real room” tests) in order to discuss the specific requirements and locate the most appropriate facility. After extensive design input, which included various technical adjustments during the 2-day testing, the results of the testing demonstrated to the team that the proposals were capable of complying with the specification.
Further to the requirements to build the building, and install the services, commissioning was achieved in addition to pre-completion of an offsite designed test. This off-site acoustic testing provided sufficient confidence to the contractor that the requirements would be met, which further proved to be the case when the onsite testing was completed.
Due to the unique design of the development, any failure to meet the BREEAM requirements would have incurred significant economic consequences for the contractor. However, due to our involvement here at Finch, the risk was curtailed and the building was handed over successfully to the delight of the end user.
If you need a building acoustician with unique specialist knowledge in Office Acoustics and BREEAM, do not hesitate to contact our acoustics expert Teli Chinelis at [email protected].
[1] Oomen, Knowles, & Zhao, 2008
