Retrofitting, while essential for long-term sustainable urban development, presents a unique set of acoustic challenges – challenges that are amplified when it comes to listed and heritage buildings.
While these buildings can feature desirable internal architectural features, worthy of care and preservation, traditional construction methods and materials often suffer from poor sound insulation and provide limited opportunities for acoustic intervention. This can result in unwanted noise intrusion, compromised indoor environmental quality and a poor user experience.

We understand the relationship between acoustics and a successful retrofit to be symbiotic, and believe considered interventions at a project’s earliest stages can breathe new life into aging structures, while improving the auditory experience, wellbeing and productivity of occupants and users.

Acoustic innovations in renovation

Modern insulation materials are capable of significantly enhancing sound insulation for refurbishment projects, improving the perception of a building from an echoey, noisy relic to a stylish, sound enhancing retrofit. However, differing standards of construction in historic buildings, often with poor tolerances or degraded materials, results in the need for a bespoke acoustic design approach.

EPR Architects’ new headquarters project ‘All Saints’ (winner of prestigious BCO and RIBA Awards), was originally constructed in 1875, where it was employed as an orphanage, a hospital and then as an archive for the Imperial War Museum. EPR were keen to reclaim and reuse the existing timber floors and expose the original brickwork, which could give rise to acoustic issues.

Working with EPR’s team we developed a design solution that involved the strategic integration of a high-performance soundproofing membrane and resilient couplings within the floor; which significantly improved the floors’ acoustic properties while preserving their historical integrity and aesthetic appeal.

All Saints also presented a unique challenge in balancing the preservation of heritage ceiling elements with the need for modern acoustic solutions. Our team was tasked with developing an acoustic design that would integrate seamlessly with the historic aesthetics of the space. To achieve this, we used CATT-Acoustic room acoustic modelling to show that acoustic wall panels could be used around the distinctive vaulted ceiling features to achieve a suitable performance without overshadowing their architectural significance.

An outside influence

Windows are often a weak point in older buildings when it comes to sound transmission. Single glazing was installed back when occupants would experience considerably lower external environmental noise levels – think horses and carts outside instead of Range Rovers! We experienced this first hand on Bruntwood’s ‘Bond’ refurbishment, a newly renovated workspace in Manchester City Centre. This Grade II* listed Victorian bank was originally built in 1862, but now finds itself having to contend with Manchester’s noisy trams and traffic from the street outside.

We undertook thorough internal and external acoustic site surveys to establish the performance of the existing façade, and then used CadnaA environmental acoustic modelling, together with our own experiences, to define the performance requirements for the refurbishment in line with modern commercial office standards. The resulting solution involved the careful addition of secondary glazing to the windows to maintain the Grade II heritage feel, while delivering an excellent indoor noise environment and a marked improvement in the energy efficiency of the building.

On Bond we also provided a schedule of non-intrusive measures to enable incoming tenants to achieve optimal acoustic comfort without compromising the listed aspects of the building. These measures included free-standing acoustic panels, carpet and shelving units with acoustic panels.
The final result was a harmonious blend of old and new, offering improved acoustic performance while appreciating the building’s historic charm.

A brighter future

Looking to the future, we are seeing continuous improvements in modelling software alongside the development of new materials and technologies. These include the integration of smart technologies (e.g. adaptive masking or soundscape systems), artificial intelligence (e.g. noise source identification), and the continued development of eco-friendly acoustic materials (e.g. biobased acoustic panels) to meet the evolving needs of retrofitted spaces.

We are already seeing the effect of innovations such as active mass dampers, that can control vibration to rigorous standards with minimal architectural compromise by simply attaching a device to the floor, and digital room scanning tools, which allow you to quickly create an accurate acoustic model by scanning a room with a smartphone.

Our comprehensive, collaborative approach to acoustic retrofit involves working closely with the client, architect and structural consultant, including the inspection and analysis of the existing building, environmental and room acoustic modelling and a deep understanding of historical context. We believe this approach, combined with our understanding and implementation of the latest modern materials, enables a sensitive, sustainable evolution for our architecturally significant buildings.

As always industry collaboration is key to progress, and we love a challenge so get in touch to discuss your past or future projects. What challenges have you faced when applying acoustic materials in retrofit projects? What innovative solutions have you encountered in the refurbishment of heritage buildings?

To discuss your project with us, please contact Jerry Rees.