Case Study – Smaller Consultancies – Hayes McKenzie

COMPANY: Hayes McKenzie

PROJECT: 25 Clifton Road

Splitting a basement off from an existing dwelling to create a flat with separate entrance from the house above in a building over 100 years old, with a party-wall between the existing dwellings that was only 3 inch lath and plaster rather than masonry, presented a project the like that no-one in the design team had ever come across before. The team had to take the existing building (which was in a poor state of repair), factor in the structural engineer’s design (which runs a 10 metre high vertical steel through the whole structure off a concrete pad in the basement with steel ‘branches’ coming off it to support/re-level the floors and ridge throughout the structure) and come up with an action plan, a list of products and an installation procedure which would stand a chance of complying with regulations.

The biggest challenge was addressing all the flanking paths in the party floor between basement and ground floor (and upper floors). The results showed the party wall was 23 dB better and the party floor was 18 dB better than the requirements of ADE, a ringing endorsement for both the planning/preparation stage and the carefully considered install stage of the works. This was the first time the professional team had all worked together, the contractor was experienced in sub-division of Victorian Buildings and the Project Manager had a history of building recording studios so was confident of understanding what was required, if also a little concerned as to the likelihood of success! The key to the success was a pre-commencement site meeting between the Project Manager and the Acoustic Consultant where the plans were scrutinised and the site walked to identify problem areas, the challenges to be faced by the existing/proposed materials and the right products to address the challenges.
There was careful consideration to marrying acoustic principles with a range of both specialist and standard products and the install technique itself. One of the benefits is the performance value of relatively inexpensive materials which the Contractor has applied in another project where the aim was to provide a better environment for the individual tenants over traditional building requirements inexpensively.


The judges were impressed at the high level of sound insulation this project aimed for and achieved. There was good communication and the great collaboration between the parties and it was pleasing that the principles had been used again elsewhere. Work of this type may not present the technical challenges that arise on buildings of greater prominence but they are an excellent example of the work which smaller consultancies undertake and show the contribution which acousticians make to a successful outcome. The judges were unanimous in declaring this the winner of the smaller consultancy award 2020.


The brochure entry for this project can be found here and the video is available here.



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