Acoustic standards, guidelines and building codes have the potential of having a profound impact on future construction, for better or worse, for years to come. That is why we at Acoustic Bulletin keep a keen eye on the developments. We’ve written about this topic on several occasions, like this post from Poland, or this one about an update to the German DIN standard, or this post about a presentation around the topics of why standards matter. We’re happy to bring you a new update, this time from Finland.
New proposal – significant improvements to acoustic conditions
The Finnish Ministry of the Environment has published a proposal for a revised version of part C1, “Sound insulation and noise abatement in buildings”, of Finland’s National Building Code. The proposed revision would significantly expand the Code’s scope of application: from the beginning of next year, it would no longer apply solely to residential buildings. Experts say the new regulations would have a direct and positive impact on people’s health and productivity.
The current part C1 of the National Building Code dates back to 1998. In terms of room acoustics, it only regulates reverberation time in staircases. For example, there are no binding statutes covering acoustics in classrooms and open-plan offices, only recommendations. Outside residential buildings, acoustic environments have been left to market forces.
Limits introduced for speech intelligibility
In addition to reverberation time, the proposed revision sets limits for speech intelligibility (STI), a particularly marked improvement for acoustics in educational premises and places of assembly. New, action-triggering limits for low-frequency noise is another positive step for health protection.
The acoustic environment in educational spaces affects the wellbeing of teachers and students alike. Students should be provided with an appropriate physical learning environment, a precondition for educational accessibility and equality. A well-designed acoustic environment can also protect and promote the health of professional voice users, such as teachers.
“Finnish learning environments have changed in many ways; open-plan rooms have become increasingly common, and more and more students are not native Finnish speakers. This makes speech intelligibility crucial,” says Environment Counsellor, Ari Saarinen, at the Ministry of the Environment who is in charge of drafting the decree laying down the new building regulations.
“When implemented, the targets that our proposal sets for flexible and adaptable spaces will have a significant impact on work efficiency,” Saarinen says.
Direct impact on health and productivity
Under the reform, the application of the decree would be extended to patient rooms, treatment rooms, educational premises, places of assembly, recreational facilities and offices. Acoustic conditions have a direct impact on the wellbeing and safety of people and public health in general.
In the future, under the reform, qualitative measurements would allow acoustic environments to better reflect the way people experience the acoustics of different spaces.
“Acoustic measurement techniques and research have come a long way in twenty years. For instance, we are now much more aware of which aspects users of various spaces find the most problematic,” Saarinen says.
The acoustic environment of open-plan and activity-based offices will also fall under the remit of the new decree. Studies have shown that acoustic conditions affect people’s coping, wellbeing and recovery ability at work. Open-plan offices are often associated with high noise levels and a lack of privacy, which increase stress in the workplace.
“When implemented, the targets that our proposal sets for flexible and adaptable spaces will have a significant impact on work efficiency,” Saarinen says.
Aiming for best value for money
More stringent regulations always entail higher costs. What if, when refurbishing an old block of flats, demolishing the building suddenly seems the only viable option due to stricter regulations?
“The decree must allow for case-by-case discretion. At the same time, we are trying to find good, pragmatic solutions,” Saarinen says.
Saarinen says that investment and operating costs have been examined separately at the drafting stage. The new decree is expected to make measurements easier, which will, in turn, reduce costs. From a financial perspective, the decree is a comprehensive solution.
Aim: a practical tool guiding building work
The revised National Building Code will only contain legally binding provisions, dispensing with guidelines. Building-related statutes issued by other authorities may be added to the new code. The aim is to clarify regulation and ensure the Code’s role as a practical tool for guiding building work.
“The decree will be supported with non-legally binding guidelines. The guidelines may refer to standards, which the decree cannot do. If the decree requires a product or space to have a certain acoustic property, the guidelines can specify which standard can be used to test that this requirement is met,” Saarinen says.
The guidelines are being drafted alongside the decree, with the goal of publishing them both at the same time. In addition to the guidelines, other manuals will be drawn up later.
The proposal for the revised part C1 of the National Building Code is circulated for comments. The aim is to have the decree enter into force 1 January 2018 without a transitional period.
The proposed values
For room acoustics, the new decree sets limit values for reverberation time (RT) and speech intelligibility (STI). At a discussion event held at the Ministry of the Environment regarding the Building Code reform, the proposed values below were considered appropriate:
Text: Terhi Rauhala
For more information on the proposal, contact Virpi Villa-Peltonen or follow her on Twitter Follow @VillaPeltonen or LinkedIn .
