Building Bulletin (BB) 93 - Acoustic design of schools

BB93 explained

Like Building Bulletin (BB)101 (BB101), Building Bulletin (BB) 93 (BB93) sets out minimum performance standards of school buildings and provides guidance on how to comply with relevant sections within the Building Regulations. However, BB93 solely deals with acoustics, was initially published in 2003, and last updated in 2014.

What is in BB93?

The main objective of having performance standards is to ensure that the design and construction of school buildings provide optimal conditions with suitable indoor ambient noise levels (IANL) for:

• Clear communication of speech between teacher and student
• Clear communication between students
• Learning and study activities

BB93 continues to describe what other noise sources can affect IANL:

• External sources outside the school premises (including, but not limited to, noise from road, rail and air traffic, industrial and commercial premises)
• Building services (eg, ventilation systems, plant, drainage etc). If a room is naturally ventilated, the IANL is calculated and measured with ventilators or windows open as required to provide ventilation… If a room is mechanically ventilated or cooled, the plant should be assumed to be running at its normal operating duty.
• Actuator and damper noise

Within BB93 there are several tables which describe specific IANL levels (in LAeq,30mins) for the various areas within a school, during normal teaching hours.

Noise being emitted by building services, such as ventilation units, should also fall in line with the IANL levels, however, there are varying tolerances on the IANL limits for the different ventilation strategies (e.g. Mechanical, Hybrid, or Natural) and what conditions they are operating under.

BB93 key points

Guides such as BB93 have meant that acoustic performance within school buildings has become more important in recent times. From a building services stand point, the importance of providing accurate acoustic data has been accelerated due to the shift of ventilation units becoming more decentralised; as units are now in the classroom itself rather than in a centralised plant room.

VES have been working with ISVR for over ten years, to provide the most accurate acoustic data for our ventilation units. ISVR (Institute of Sound and Vibration Research) is part of the University of Southampton, is a founding member of the Association of Noise Consultants and is renowned for its contributions to reducing noise and vibration in many engineering applications.

With the help of testing at ISVR, we sought to understand how noise is generated and propagated by our units and to design them from the ground up to emit less sound - we did not just seek to fix existing noise issues on site.

For products designed for classrooms, VES test every size in the range of units which we offer. This allows our customers to be certain that our products meet BB93 guidelines.

To get a better and more detailed understanding of Acoustics in schools, please see our Acoustic Technical Guide on the subject.