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acoustic advice

Acoustic advice and acoustic surveys

Acoustic advice means investigating sound in and around a building: we measure what actually happens, test the measured values against the applicable standard and advise which measure solves the problem. KGI Groep has done that since 1994 as an independent acoustic consultancy in Amsterdam, with over 10,000 reports. We do not sell insulation materials and we do not carry out any work ourselves, so we have no commercial interest in the advice we give. A survey starts from 1,598 euros excluding VAT.

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When do you need acoustic advice?

In practice, people come to an acoustic consultant for four reasons. For a permit: the municipality asks for an acoustic report when a property is split, converted into rooms or changes function. For a dispute: you want the nuisance from the neighbours, a homeowners' association floor or a hospitality venue recorded in figures rather than in feelings. At handover: you want to know whether a new-build dwelling or a renovation achieves what was promised. And for a complaint: there is disturbance, but nobody knows where the sound comes from.

Architects, developers and hotel owners also bring us in before construction starts, when a design can still be adjusted and an acoustic mistake is cheaper on paper than in concrete. Installations are another common reason to seek advice. A heat pump or air conditioning unit close to the property boundary has to meet a limit of 40 dB(A), and that can be calculated in advance.

Svantek SV 971A klasse 1 geluidsmeter

An independent consultancy or a party that also sells insulation

Many companies that measure sound also sell the solution: insulation material, soundproof glass or acoustic panels. Their measurement is then the first step in a sales pitch. KGI measures and advises, nothing more. We do not supply materials, we do not install anything and we have no stake in the measure you choose. What we advise follows from the measurement, even when the outcome is that you are better off doing nothing because the gain is too small to justify the investment.

That difference hits your wallet. A wrongly chosen measure costs thousands of euros and does not solve the problem: a heavy ceiling does not stop airborne sound that enters through the side wall. So we first establish where the sound comes through and which frequencies dominate, and only then what can be done about it. A noise nuisance inspection is where that starts.

How an acoustic project runs

A project consists of four steps. During the intake we discuss your situation, the purpose of the survey (permit, dispute or handover) and who is going to read the report. That determines which measurement is needed. On site we measure with Class 1 equipment, the most accurate category of measurement equipment. A measurement between two dwellings usually takes half a day. Variable or night-time nuisance calls for a long-term measurement of one to four weeks.

Then come the analysis and the report: the measured values, the test against the standard, the sound leaks found and advice with the expected improvement in dB per measure. For a permit survey we usually start within two weeks of approval and deliver the report within ten working days. If you need it sooner, because of a court date or a municipal deadline, an expedited procedure is available.

What is in an acoustic report?

The report contains the measured values per room combination, the measurement method and equipment used, and the test against the framework that applies to you. That is usually the Dutch Building Decree (Besluit bouwwerken leefomgeving, BBL, formerly Bouwbesluit 2012): impact sound LnT,A of at most 54 dB and airborne sound DnT,A of at least 52 dB. Measurement is carried out in accordance with NEN 5077 and NEN-EN-ISO 16283, and for façades we calculate in accordance with NEN-EN 12354-3.

Where no statutory requirement applies, for example between two existing dwellings, we express the quality in the classes of NEN 1070, from K=1 (excellent) to K=5 (very poor). That way you see what an improvement delivers in practice. Because we are independent and measure in accordance with these standards, the report can be used with the rental commission, the homeowners' association, the municipality and the courts.

NEN-EN-ISO 16283NEN-EN 12354-3NEN 5077NEN 1070

What does an acoustic survey cost?

The price depends on the type of survey, not on the degree of nuisance. Our starting rates, excluding VAT: noise disturbance inspection on site from 1,598 euros; noise measurement of impact and airborne sound compliant with NEN 5077 from 1,998 euros; long-term measurement of one to four weeks from 2,598 euros; acoustic report for room conversion or a conversion permit from 2,598 euros; calculation-based assessment of a heat pump or air conditioning unit from 1,098 euros, with an on-site measurement 2,598 euros; façade insulation and traffic noise from 2,498 euros.

What you ultimately pay depends on the number of room combinations, the number of measurement locations and the complexity of the building. You receive a quote in advance, so you know where you stand before we come out to measure. If you have legal expenses insurance, many policies reimburse the cost of a dispute in full or in part, and you can submit our quote to them directly.

Which survey fits your question?

If you hear the neighbours talking or the television through the wall, you are dealing with airborne sound. If you hear footsteps and chairs being dragged, it is impact sound, and that calls for a different measurement and a different solution. If the nuisance is variable or occurs mainly at night, a measurement of a few hours misses exactly those peaks and a long-term measurement is the better choice. If the problem is vibrations you can feel, from traffic or construction work, we measure those separately in accordance with the SBR guideline.

If there is a low, persistent hum, low-frequency noise is often at play, and that only becomes visible once the measurement runs far enough down the frequency range. If a room sounds hollow and echoing, reverberation is the issue, not insulation. If you are not sure, we determine during the intake which survey answers your question. That saves you a measurement that does not give the answer.

FAQ

Frequently asked questions

What does an acoustic consultant do?

An acoustic consultant investigates how sound behaves in and around a building. They measure the sound insulation or the sound level, test those values against the standards and against the Dutch Building Decree, and advise which measure solves the problem. At KGI it stops there: we measure and advise, we do not sell materials and we do not carry out any work ourselves. You choose the contractor yourself.

What does an acoustic survey cost?

That depends on the type of survey. A noise disturbance inspection on site starts from 1,598 euros excluding VAT, a noise measurement of impact and airborne sound compliant with NEN 5077 from 1,998 euros and a long-term measurement of one to four weeks from 2,598 euros. An acoustic report for room conversion or a conversion permit costs from 2,598 euros. The final amount depends on the number of room combinations and the complexity of the building. You receive a quote in advance.

When do I need an acoustic report?

There are three situations in which a report almost always comes up. For a permit, because the municipality asks for acoustic evidence when a property is split, converted into rooms or changes function. For a dispute with the neighbours, the homeowners' association or a business owner, because a measured figure carries more weight than a complaint. And at handover of new construction or a renovation, to establish whether the sound insulation achieves what was agreed.

Is an acoustic report usable in legal proceedings?

Yes, provided it is drawn up independently and measured in accordance with the applicable standards. Our reports are based on measurements made with Class 1 equipment in accordance with NEN 5077 and NEN-EN-ISO 16283, and test the results against the Dutch Building Decree. Because we do not sell materials or installation work, we have nothing to gain from the conclusion. That means the report can be used with the rental commission, the homeowners' association, the municipality and the courts.

What is the difference between acoustic advice and a noise measurement?

A noise measurement produces figures: how many dB come through, at which frequencies and at what times. Acoustic advice is the step after that: comparing those figures with the standard, establishing along which path the sound enters and determining which measure remedies it and how much gain in dB that realistically delivers. A measurement without interpretation tells you that there is a problem, but not what you can do about it.

How long does an acoustic survey take?

A measurement between two dwellings usually takes half a day on site. With variable or night-time nuisance we record continuously for one to four weeks, because a short measurement misses the peaks. For a permit survey we usually start within two weeks of approval and you receive the report within ten working days. If there is time pressure from a court date or a municipal deadline, an expedited procedure is possible.

Does KGI also sell insulation material?

No. We measure, calculate and advise, and we do not supply insulation materials, soundproof glass or acoustic panels. We do not carry out any work ourselves either. As a result we have no commercial interest in a particular solution, and we can also advise doing nothing when the expected gain is not worth the investment. You contract the work out to a party of your own choosing.

Contact

Consultation or direct quote

Schedule a free consultation or request a direct quote via the form. We respond within one business day.

+31 (0)20 808 70 90
info@kgigroep.nl
Keizersgracht 241
1016 EA Amsterdam