“Very proactive and extremely helpful, especially with technical queries. I would not hesitate to recommend and will certainly be using them again in the future.”



Under CDM2015 regs we have found CASS ALLEN to exercise a level of professionalism and due diligence which is second to none. We would therefore definitely recommend CASS ALLEN as our preferred acoustic consultant, for all of our projects.’


SF - Taylor Wimpey South Thames

“I was very pleased with their technical knowledge and professional approach when dealing with a very awkward purchaser as well as the local authority.”


JH, Telford Homes

“Cass Allen went above and beyond to help with the Acoustic planning performance and conditions regarding the Greenwich Creekside project…”


LM, Capita plc

“Good comprehensive reports and advice at all design stages. Very flexible and professional, provided attendance at acoustic cladding tests at short notice.”


DF, Berkeley Homes

“Cass Allen have assisted us on a number of our projects. I’ve been impressed with their thorough and professional approach.”


MT, Lark Energy

New guidance for the acoustic design of schools

The Association of Noise Consultants (ANC) and the Institute of Acoustics (IOA) have released their latest guidance for the acoustic design of schools. The document, “Acoustics of schools: a design guide”, replaces the guidance previously published in the 2003 edition of Building Bulletin 93 and is now the official guidance for compliance with BB93:2014. A full version of the guidance can be found here.

The guidance reflects the changes in BB93 requirements between the 2003 and 2014 editions. A summary of the key changes is given below:

  • New noise limits for external school activities.
  • Examples of suitable natural ventilation strategies are provided for compliance with BB93 internal noise limits.
  • New information and limits for equipment in teaching and learning spaces.
  • Guidance on how to comply with BB93 sound insulation criteria. This includes examples of construction details, new guidance on curtain walling and clarification of requirements between circulation areas, classrooms and non-teaching rooms.
  • Significantly more guidance on the design and limitations of open plan teaching spaces.
  • Detailed guidance on how to achieve the new targets for refurbished school buildings given in BB93:2014.
  • A new calculation methodology for complying with BB93 in relation to reverberation control in sports halls, swimming pools, gymnasia, dance studios and other normally unfurnished activity spaces.
  • A new method for assessing the sound insulation performance of window actuators.
  • New guidance for the design of music rooms as per the changes in BB93.

The ANC have also revised their guidance on the testing of schools to bring it in line with the new version of BB93. The new testing guidance can be found here. The ANC are also planning to introduce a new accreditation scheme for the testing of schools similar to the current scheme for sound testing in residential developments (Part E testing). However, the testing of schools is not mandatory and therefore it is not clear how popular this scheme will be.

We hope you find the above useful – please get in touch if you would like to talk through the acoustic design or testing of schools further.


Get in touch

We hope you’ve enjoyed browsing our website but if you have any questions feel free to call us to talk through any acoustic issues you may be facing on your projects. The best person who can help with specific queries can be found here.