Kevin Dundas, Supply Chain Manager (Products) of Willmott Dixon, discusses the challenges of specifying moveable walls and his support for the FIS Acoustic Verification Scheme.

In the built environment, main contractors are constantly striving to get the best results for their clients, which is why the specification and performance of building products is so critical, according to Kevin Dundas, Supply Chain Manager (Products) of Willmott Dixon, who is an advocate of the FIS Acoustic Verification Scheme.

Kevin has spent the past 17 years working in construction in various roles from buying, site management and supply chain management. He is passionate about continuous improvement and says collaboration is what will drive the industry and result in vastly improved end products.

He said for contractors such as Willmott Dixon, the scheme has become a game changer, as it has meant the company can specify products with confidence that it is on a level playing field.

“As a business, we noticed various issues with moveable walls. These included broken slabs fitted inside panels to provide weight, misleading or missing acoustic data, large panels fitted on a single track, to name a few,” said Kevin.

Historically, acoustic testing and test certificates have been very inaccurate, in Kevin’s view.

“It has been commonplace for many years for manufacturers to provide just the front page of a test certificate. This first page tells us very little in the way the panel has been tested,” he said. “Whilst it may not be an outright lie, it is very misleading. Our teams on site have a lot to deal with and are responsible for checking a lot of data.

With these reports not being clear and presented in a misleading way, it can result in us providing a product to our customers that does not meet their requirements.

“As a business, we aim to astonish our customers. This approach goes against all we stand for.

Testing falsifications
So what are some of the scenarios Kevin has experienced in terms of testing falsification?
“The most common is the term “testedinoperable” where a company has tested the moveable wall but in a way that makes it inoperable,” he said. “This generally includes sealing all the gaps with rockwool and tapes prior to the sound testing. This is obviously unacceptable to anyone. Surely we must have test evidence based on how the wall will be used?

If inoperable, it is no longer a moveable wall and becomes just a wall.”

Another issue Kevin has encountered with some tests currently provided is the standard they are testing against. He said: “It happens all too often that we will be referred to a test that is in accordance with a standard from nearly 40 years ago, despite the test being carried out in the past five years. Some companies will send test data from companies that no longer exists. It is an old test and they feel it is acceptable to just keep using it to avoid carrying out new testing. But this gives no assurances that the wall will perform as required.”

So how important does he think an acoustic rating on a moveable wall is? “It all depends on what the project requires. If the acoustician has designed the building and requires a wall to be a certain dB rating, then itis vital that the wall achieves what is required. Acoustics play a huge part in the success of a building and the wellbeing of those using it. We cannot compromise on this,” he said.

Contractors or specifiers will benefit from the scheme because it addresses the issue of misleading use of data and means that
the product selected has been properly and independently tested, he said.

Moveable wall challenges
Highlighting the benefits and negatives of different types and mechanisms of moveable walls, Kevin said he believes it is important to engage early with moveable wall partners.

“This will help them understand what the building is being used for, the amount the wall will be opened and by whom,” he said. “If the wall is in an unmanaged building and will be opened on a regular basis, it is key to ensure the mechanism is robust and well-engineered. Some I have seen in the past have looked very botched and it is hard to see how they will last beyond a year or two.”

So what are the longer-term impacts to Willmott Dixon when products do not meet acoustic standards? “These can materialise as loss of profit owing to rework or in the worse cases, replacement. There is also the loss of reputation,” said Kevin. “This one is very hard to quantify but can have a huge impact on a business. We like to pride ourselves on delivering a perfect product that is right first time, every time. If a customer is not happy then we are not doing our job correctly.”

Outlining the Building on Better strategy, Kevin said it’s always possible to keep driving improvement. “We can always keep learning and getting better! The aim is that through our work we build lives that are less ordinary,” he said.

“Willmott Dixon’s Building on Better strategy is about getting the best results for our customers by ensuring nothing is taken for granted, no matter how good we think it is. However excellent the project, we can always learn and improve.”

He said his company’s teams are required to examine and challenge everything and never accept that something cannot be improved, even if it already works well. “Ideas are never dismissed, no matter how small or irrelevant, and there’s a zeal for not accepting the status quo just because it works – because who knows if it will work tomorrow?”

Speaking about future specification challenges, Kevin said: “The challenges we face are finding more like us to follow. We need more tier 1 contractors to know about the issues facing the moveable wall industry and to stand up and do something about it as we have. While the industry remains focussing on cost alone, we will never improve.”

The scheme has been extended to include the verification of glazed partitions. Manufacturers wanting to find out about getting data verified can request a copy of the FIS Acoustic Verification Scheme Manual by emailing