Poor home sound insulation costs – privacy and cash

city scape - west londonFollowing his presentation at this year’s recent Solent Acoustics Conference ‘Acoustics in the Built Environment’, acoustician and lecturer Jonty Stewart writes on some of the issues surrounding sound insulation and in particular the problems it causes.

The first thing I would say is that “poor” sound insulation depends on whom is being affected: to the builder or develope. “Poor” sound insulation can probably be loosely defined as anything which doesn’t meet the legally-required performance criteria [see Section 0, page 12 of Approved Document E (ADE)] and which therefore must be upgraded to the point where it does, with all the attendant extra time and money that will take; to the person actually living in the dwelling, “poor” sound insulation is more likely to be anything which allows disturbance of their privacy, irrespective of whether the measured level meets the requirements of ADE. It’s worth noting that simply meeting the required performance standards is NOT an indication of reasonable levels of privacy between dwellings; personally I wouldn’t be happy living in a house with a party wall offering less than about 55 dB of attenuation to airborne noise, which is 12 dB above the lowest level required in ADE.

To my mind, merely achieving the minimum required performance criteria is a false economy. Builders and developers should be able to add value to their properties by building better walls and floors. They are required to have the sound insulation tested in any case, so why not make the results a selling point? It is surely better to be able to tell prospective purchasers or renters that the performance far exceeds the criteria, because they may then have some confidence in their ongoing privacy and quality of life. One of the less endearing psychoacoustic properties of sound is that, once a listener identifies a particular sound as a problem, they immediately become more sensitive to it, so it becomes a bigger and bigger problem as time goes on.

One of the most common mistakes made by builders and developers is to treat sound insulation as an afterthought, and it’s the one which costs them the most money. Use of inappropriate or insubstantial treatments, incorrectly-installed treatments, or treatments which are incompatible either with the rest of the construction or with each other, all invariably lead to poorer sound insulation, which in the worst cases proves to be unacceptable and has to be fixed. The most fundamental advice I can offer is to consider the sound insulation before you even pick up a hammer or a screwdriver. Do it at the planning stage when the worst that can happen is that you might need to re-draw your plans.

The other thing I would strongly recommend is seeking expert help. If you need legal help you ask a solicitor; if you need to know what size of beam you’ll need to support a roof, you ask a structural engineer; if it’s a legal requirement for your sound insulation to meet certain standards, doesn’t it make sense to ask a sound insulation expert? Getting an expert involved at the planning stage means that inappropriate and incompatible treatments are more likely to be spotted and fixed before they are constructed, thus saving money further down the line. For conversions in particular, having an expert visit the site and recommend appropriate treatments BEFORE work begins is like paying your insurance premium – obviously there’s a cost, but it is substantially less than the cost if it were all to go wrong.

Sound insulation has a real and lasting effect on people’s lives, and can mean the difference between feeling safe and protected in your own home, and feeling trapped next to the neighbour from hell. For developers, approaching sound insulation in the right way can mean the difference between selling your property at a significant profit, and making a substantial loss because of the costs of remedial work on a failed sound insulation

Jonty Stewart is a self-employed Acoustic Consultant, Senior Lecturer at Southampton Solent University, and current Chair of the Registration Scheme Committee which quality assures sound insulation testing for the Association of Noise Consultants – who provide expert help and advice with sound insulation or any other aspect of noise and vibration.





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