“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


Acoustic design for schools in the UK is largely based on the guidance contained in Building Bulletin 93. We are very experienced in designing to this document and also negotiating derogation from BB93 where operational considerations means that it is not desirable to design to BB93.

We have advised both Educational Authorities and also Main Contractors across a wide range of schools and further education facilities. These have included several schools for students with special educational needs, where conditions need to be very tightly controlled to ensure good educational conditions.

New Recording Studio complex – ARU, Cambridge

Client: Anglia Ruskin University 

Scope: Anglia Ruskin University commissioned Cass Allen to design a suite of five recording studios and associated control rooms for their Cambridge campus. We achieved the design brief that required a complex in line with full commercial standards.

Library – Clapham One Development

Client: Studio Egret West

Scope:  Our role was to design the internal acoustics of all three parts together with discharging planning conditions related to environment noise emissions from the CHP and cooling plant. The central part of the library is also to be used as a music performance space.

This was complicated due to the elliptical floor shape, which can result in unpleasant acoustic focusing effects. The solution (developed after extensive room modelling) was to add diffusion to the walls in the shape of the glazed areas visible in the photograph and also to cant the walls outwards slightly to reflect sound up to the absorptive/diffusive ceiling.

New Skills College – Bristol

Client: Balfour Beatty
Architects: AWW

Scope: The new South Bristol Skills College caters for a wide variety of courses, from vehicle maintenance and construction to beauty therapy and hairdressing. In additional, the building contains two large atria (shown above) which are used for private study, catering facilities and arts performance. Each type of space required detailed acoustic design to ensure that the acoustic characteristics of the space fitted the intended use, whilst maintaining a consistent design aesthetic.

New School and Residential Development in Hackney

Client: Telford Homes
Architects: GHM Rock Townsend

Scope: Cass Allen are advising on a unique mixed-use residential/school development in Hackney on behalf of Telford Homes and the London Diocesan Board for Schools.

The proposal comprises a school at ground and first floors, a second floor open-air multi-use games area. With 100 residential flats stacked above the school facility.

Mayor of London Boris Johnson commenting on the scheme said: “The design for the redevelopment of Holy Trinity School is pioneering and cleverly tackles the need to provide more housing and more primary school places.”

Campus Expansion – Fareham College

Client: Bouygues UK
Architects: Perkins Ogden Architects

Scope: Cass Allen was instructed by Bouygues UK to advise on the acoustic design of a new two-storey teaching block at the Bishopsfield Road Campus of Fareham College.

The new accommodation includes a professional quality studio theatre, dance studio and also music and media studios with music rehearsal and recording facilities.

Mixed Use Residential-Educational Development in Rotherhithe

Client: Telford Homes

Scope: Cass Allen are providing Telford Homes with acoustical input to the design of a 19 storey mixed-use development comprising a primary school, secondary school and 6th Form college on the lower floors with residential dwellings above.

Our role is to aid in discharging a number of noise and vibration related planning conditions attached to the development. These include building envelope design as well as developing mitigation against the noise impact of the students at the site on residents above.

New Skills College – Fareham

Client: Leadbitter Group
Architects: Perkins Ogden

Scope: Cass Allen have been providing Leadbitter Group with acoustic design guidance for a new skills college at Fareham. The assessment included noise surveys at the site and at the existing college facilities, 3D computer noise modelling, a sound insulation design assessment, detailed reverberation calculations, a plant noise assessment and preparation of documentation to support the planning application. A challenge of the project was the use of natural ventilation in an area close to an active airfield.

New Performing Arts Building – The Brit School, South London

Client: The Brit School
Architects: Daniel Connal Partnership
Engineering Consultants: Cundalls

Scope: The Brit School is a unique performing arts college in Croydon, South London with former graduates including Katie Melua, Amy Winehouse, Kate Nash, Leona Lewis, The Noisettes, Athelete and many others. The new performance building contained studios, rehearsal and performance facilities for dance and music – all designed to standards well in excess of BB93. Our involvement also extended to acoustic design of the refurbishment to the existing school.

New Secondary School – Bradley Stoke, Bristol

Client: Kier Construction
Architects: AWW
M&E Consultants: Mitie

Scope: To acoustically design this secondary school to comply with Part E of the Building Regulations and Building Bulletin 93. The school lies close to the M4 and M5 intersection and so external noise levels required high performance facades. We then carried out Pre completion tests, which showed that all design targets had been achieved.

Primary School Extension – Teddington

Client: Morgan Sindall
Architects: GDM Architects

Cass Allen has provided Morgan Sindall with acoustic design guidance for a 2-storey extension at Hampton Wick Primary School in Teddington.

The expansion comprises 6 classrooms, 6 group rooms, a library, an extension of an existing hall/gymnasium and ancillary areas.

Using a 3D noise model of the new extension and surrounding area, Cass Allen assessed the design to ensure internal ambient noise levels will be achieved to satisfy BB93 (the acoustic design of schools) and Part E requirements. An external mechanical plant noise impact assessment was also carried out to ensure noise emission levels will not disturb school users and nearby residents.

Primary Academy Phase 3 Extension

Client: Hillyfield Primary Academy
Architects: Hayhurst and Co

Cass Allen Associates has been instructed by Hillyfield Primary Academy to assess the acoustic
design of their new extension under the new BB93.

The project is unusual as the two storey extension has two large open plan areas including a number of classrooms and group rooms. There will also be associated ancillary areas (internal toilets, circulation areas, store rooms etc.) and one self-contained studio on the ground floor.

Cass Allen is providing on-going help to design the extension advising on sound insulation, reverberation treatments and speech intelligibility to achieve BB93 requirements.

Student Accommodation in Walthamstow

Client: Taylor Wimpey East London & Watkin Jones

Scope: Cass Allen was instructed to act as acoustic consultants on behalf of Taylor Wimpey & Watkin Jones to provide acoustic design advice for this student accommodation project.

Cass Allen started work on the development a number of years ago when we carried out the initial noise impact assessment to support the planning application for the masterplan.

We were then involved in the preparation of the Section 61 agreement. This included an assessment of construction noise associated with the development to minimise the risk of adversely impacting the breeding of migratory birds that are known to nest in the nearby reservoir.

More recently, we have been providing detailed acoustic design guidance to ensure that acceptable noise environments are provided in the student accommodation, which is being built by Watkin Jones, and the 475 residential units, which are being built by Taylor Wimpey.

Library Refurbishment – Chelmsford

Client: Anglia Ruskin University
Project: Queens Library
Planning Consultant: Gleeds

Scope: We have started work on the refurbishment of the library on ARU’s Chelmsford site. The library is built around two atria and one of the key aims of the refurbishment is to reduce noise transfer from floor to floor via these atria. We have completed transmission tests inside the library to understand how sound is reflected and absorbed from the various architectural features and are now working on the modelling, which will inform the internal fit-out and finishes.

Student Accommodation Scheme for City University in London

Client: Mace
Architects: TP Bennett

Scope: Cass Allen provided Mace with acoustic design guidance for this 800-room student accommodation development which is arranged in two blocks.

The scheme is located on a 1.5 acre site and includes a 34,000 sq ft sports hall and 20,000 sq ft of teaching accommodation.

We worked on the acoustic design of the external facades to achieve acceptable noise levels in the student rooms. We also worked on the design of the building services and the sports hall to ensure noise breakout from these areas did not disturb surrounding sensitive receptors.

New Primary School – Milton Keynes

Client: Milton Keynes Council
Developers: English Partnerships
Architects: Architecture MK

Scope: Acoustic design to BB93 standards of this large 3 story primary school in Central Milton Keynes. The school is designed to be the first carbon neutral school in the country incorporating a wide range of sustainable energy sources into the design.

New Secondary School – Merchant’s Academy, Bristol

Client: Cowlin Construction
Architects: AWW
M&E Consultants: Mitie

Scope: To acoustically design this new £23m academy to comply with Part E of the Building Regulations and Building Bulletin 93. We then carried out Pre completion tests, which showed that all design targets had been achieved.

New Secondary School – Milton Keynes

Client: Milton Keynes Council
Architects: Architecture MK

Scope: Acoustic design to BB93 standards of this large secondary school in Central Milton Keynes. This project is one of many educational projects that Cass Allen have advised on for Milton Keynes Council, including Special Schools, primary and secondary schools, and several refurbishments.

New School – Portsmouth

Client: Portsmouth College
Architects: HNW Architects
Planning Consultants: GVA Grimley

Scope: to assist with achieving planning permission for the replacement of Portsmouth College. We carried out baseline noise surveys and 3D modelling to help establish the most effective layout for the college from an acoustic perspective. Of particular concern was the presence of a breeding ground for Canadian Geese on the site, which the Council required should not be disturbed during the construction phase. The photograph shows the proposed college superimposed on the existing college, which is to be demolished in stages.

College of Construction – Lewisham, London

Client: Stanhope plc
Architects: Emoli Petroschka
Planning Consultants: Frontline Projects

Scope: As part of ongoing long-term developments at Lewisham College, the Construction Faculty plans to move to temporary accommodation in a disused factory site (top photo). Cass Allen’s brief was to design the acoustics of the temporary site so that they were at least as good as those the students currently enjoyed, but to minimize costs in view of the temporary nature of the building. We first surveyed the existing acoustic conditions in the current college and then using 3D modelling developed a scheme of internal acoustic barriers coupled with acoustic absorption (lower photo), which provided the necessary acoustic separation between adjacent work areas.

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.