Case Study: Dartington Primary School Nat Vent Box

Dartington Primary School is located in close proximity to the A384; a large busy road. A number of natural ventilation strategies were developed in cooperation with Arup, including the use of landscaping as a barrier. This inspiring solid timber project presented challenges internally and externally. Natural ventilation is achieved through an external bulkhead cross-venting through the roof.

The first step of any noise break-in assessment is to establish levels across the site. This was done by carrying out noise monitoring throughout the site, over the full operational hours of the school.

A noise map was then created and used to assess the required level of attenuation required by facades of the school. The results indicated that the noise levels at the facades to the classroom block were higher than desirable.

The solution to the high noise levels at the building facade was to naturally ventilate using an external ground floor bulkhead containing the NVA, with hot air flowing out through openable window vents also containing the NVA. This solution allows for natural ventilation when it would otherwise not be possible through an open window for example. In addition to this, an acoustic screen and a strategically placed earth bund were designed to reduce noise levels at the classroom facade. The bund was formed from recycled tires, adding to the sustainability credentials of the building. Dartington Primary School is an inspiring development because a solid timber construction system has been used. BB93 also sets room reverberation requirements and the exposed timber in combination with barn shaped classrooms required some form of room acoustic treatments. The solution used was several acoustic beams provided by MACH Products (below).

The school met all BB93 requirements and BB101 ventilation specifications. Not only this but the finished design was pleasing and added function to the facade besides ventilation. The build was featured in ‘BD Reviews’ sustainability issue, a bow to the innovative design by MACH Acoustics, White Design and Arup. The photo below features the wooden beams put in place to reduce the reverberation. Click the preview below to download the full case study.

Open Plan Teaching

Open plan teaching is becoming increasingly popular due to the benefits offered by this form of teaching and learning environment. Open plan spaces offer increased levels of flexibility, sharing of resources, cross learning between teachers and between pupils, enhanced visual and auditory communication as well many other educational benefits.

Alsops open plan teaching space option 1

Open plan within the educational environment can take many forms; learning plazas, breakout spaces, library spaces, shared resource areas, external spaces etc. These spaces have a diverse range of requirements and needs. In addition to this, open plan teaching is carried out from reception years right through to higher education, and then of course onto our working environment. This further increases the range of requirements and diverse needs relating to these types of spaces. 

Alsops open plan teaching space option 2

Often, a limiting factor of open plan spaces is poor acoustics. In MACH Acoustics view, this shortfall is due to two main factors; insufficient importance given to the acoustic design of the spaces (i.e. not employing a good consultant) and a lack of understanding of the specific needs of a learning space. It is MACH Acoustics view that the starting point in the design of an open plan space is to understand what is required from the space and its specific educational needs. Once these are understood, the acoustics design can be established and such to ensure that these requirements are met and that the clashes between acoustics and open plan can be resolved. 

BB93 ‘Acoustic Design of Schools’ provides some basic requirements with respect to open plan and these requirements are covered in Section1.1.7 Speech intelligibility in open plan spaces. In summary, this section states that the speech intelligibility level and sound transmission index (STI), are required to be above 0.6 and 1 respectively. The STI of a space is determined through detailed software calculations.

BB93 ‘Acoustic Design of Schools’ also provides advice in the form of case studies which are presented in Case Study 7.2 – An investigation into the acoustic conditions in three open-plan primary schools (BB93 Page 97) and Case Study 7.3 – Remedial work to an open-plan teaching area in a primary school (BB93 Page 107). These case studies look at the effects of acoustic treatments, acoustic screens, seating layouts and other aspects. It is MACH Acoustics view that this information is relatively limited and that better, simpler and more flexible solutions can be found.

MACH Acoustics has undertaken a number of projects containing open plan spaces ranging from open plan breakout spaces in primary schools through to full plazas providing the full educational spectrum to 60/90 secondary school pupils at a time. Two of these spaces include the New Line Learning Plaza and the New Line Learning Plaza 2 at Oldborough School, Kent. Case studies on these two schools are presented within this PDF document - Open Plan Teaching.

In addition to these projects, MACH Acoustics is working alongside White Design and Monmouthshire County Council in the design of two key educational open plan facilities; Green Lane Primary School and Castle Park Primary School. Using this blog, MACH Acoustics will be presenting our designs as they progress.