Cahill Design Consultants has been delivering acoustic design and consultancy services for over a decade. With a highly experienced and creative team of acoustic engineers, our clients and collaborators recognise the value of good acoustic performance. Even so, it’s worth stepping back to consider how sound is shaped, why early involvement makes a difference, and where a project can lose or gain acoustic value.
Whether the project relates to a school, housing, workplace, public or entertainment venue, the same core principles of acoustic design apply. The main factors to consider are sound insulation and noise control, room acoustics and sound quality, as well as building services and vibration management.
What is acoustic design?
Acoustic design shapes how sound behaves in and around buildings. It focuses on predicting, controlling, and enhancing sound to create spaces that sound and feel right for their purpose.
It is important to distinguish between sound and noise: while all noise constitutes sound, not every sound is classified as noise. Noise usually indicates sounds that are perceived as unwelcome or disruptive. Acoustic design considers both aspects by mitigating intrusive noise and improving sound quality where clarity and atmosphere are essential.
A well-designed acoustic environment improves occupant experience, by boosting building functionality, for example clearer speech in classrooms, less background noise in restaurants or privacy in open offices.
At CDC, we consider acoustic design an integral part of a building’s environmental strategy, rather than an element added later in the process. Early involvement in a project (be it new construction, refurbishment, or a change of use) means our engineers can help shape design decisions, support risk management and deliver the right acoustic outcomes.
Why is it important?
Acoustics affect how spaces operate and how people experience them. Poor sound control or unsuitable sound levels may result in distraction, discomfort, lower productivity, issues with compliance and adversely affect health.
In schools and universities, high levels of reverberation may disrupt learning and teaching. In residential settings, inadequate airborne (sounds that travels through the air, e.g. voices or music) or structure-borne sound insulation (sounds that travels through a building’s structure, such as footsteps or machinery vibration) can affect privacy and general wellbeing. In healthcare environments, acoustics even have the potential to affect patient recovery.
The Building Regulations set out mandatory acoustic standards. These include BB93 (Acoustic Design of Schools), Approved Document E (Resistance To the Passage of Sound) and Approved Document O (Overheating).
Other codes and guidance are often used at project design stages, such as ProPG, BS:8233 2014, and HTM 0801. These provide recognised, structured approaches to design and assessment, helping ensure consistency, support compliance and demonstrate best practice across projects.
Early integration of acoustic design provides greater flexibility and can reduce cost throughout the project’s lifecycle.
We also support later-stage initiatives by recommending practical retrofit solutions and conducting compliance verification through testing and reporting.
In short, good acoustic design ensures buildings achieve their intended performance standards. Beyond meeting technical requirements, it also promotes comfort and addresses the expectations of occupants.
Variables that affect sound in your building
Reverberation Time
This is the time it takes for sound to fade in a space. Long reverberation can cause speech to become muddled and unclear, while very short reverberation can make a space feel too ‘dead’. Material choice, ceiling height and room volume all influence this.
Ambient Noise Levels
Noise from building services such as HVAC (Heating, Ventilation, and Air Conditioning) or external sources such as traffic or nearby rooms can raise ambient noise levels and make communication difficult. Acoustic design aims to reduce and manage these sources through careful planning and specification.
Sound Insulation
This refers to the capacity of walls, floors, and doors to reduce airborne and impact noise. Requirements may differ based on building type and intended use. Our expertise includes consulting on construction methods, junction detailing, and appropriate materials to meet specified acoustic standards.
Room Geometry
The dimensions and configuration of a room influence how sound reflects and spreads. Irregular shapes may result in flutter echoes or acoustic dead zones, whereas curved or diffusive features can spread sound waves more evenly, thereby enhancing overall sound distribution.
Absorption
Acoustic absorption happens when sound waves hit porous materials. Surfaces like acoustic ceiling tiles or wall panels help reduce reverberation and improve speech clarity.
Diffusion
Diffusion distributes sound energy evenly throughout a space, minimising areas of concentrated sound and reducing undesirable reflections. In auditoriums or music venues, it creates a more balanced and immersive acoustic environment.
Vibration and Structure-borne Noise
Vibrations from impacts or mechanical systems can travel through structural elements, particularly floors, ducts and pipework. These problems often arise when MEP (Mechanical, Electrical or Plumbing) systems are installed without coordination with acoustic design.
At Cahill Design, all of these factors are considered together, and solutions tailored to the building’s use, construction type, and project priorities.
How acoustic design fits into your project
Our acoustic consultants usually join projects from RIBA Stage 2 or earlier, advising on spatial layouts, material specifications, and performance objectives. We also work with the design team through the construction stage of works. We support live sites, fit-out phases, and post-completion stages, providing testing, validation, and remedial advice where needed.
Depending on the scope of work, we may provide:
- Environmental noise surveys
- 3D acoustic modelling and prediction
- Sound insulation design advice and detailing
- Internal acoustic treatments
- Set the Acoustic Strategy
- Mechanical services noise assessment
- Pre-completion sound testing and reporting
Our objective is to work seamlessly with design teams and programmes. We provide proactive, pragmatic guidance that supports planning approvals, ensures building control compliance, and helps to create environments that meet their intended performance standards.
Speak to Cahill Design
If acoustic performance is a key factor in your project, or you are encountering challenges on an active site, our team is available to discuss your specific requirements. With more than a decade of consultancy experience spanning the education, residential, commercial, and leisure sectors, we deliver clear and authoritative guidance throughout every phase of the building lifecycle.
Call us on 0203 950 9082 (London) or 01206 809 598 (Colchester), or [fill in our enquiry form] to speak with one of our consultants about your acoustic design needs.
