The noise impact assessment process typically assesses how noise emissions from a proposed development (commercial, industrial, renewable energy, etc.) affect existing receptors in the surrounding area. Impacts are assessed in the context of ‘bringing noise to people’. In recent years, there has been a growing requirement to assess the reverse scenario, where development will ‘bring people to noise‘. This applies to residential developments, for example, it is proposed to construct a housing development or apartment complex in an area already exposed to noise.
In most cases, the chief concern is road traffic noise, but it also applies to railway noise, aircraft noise, and industrial noise. For instance, a developer may propose constructing a Large Residential Development (LRD) on a greenfield site within 1 km of a major road, where traffic noise levels are elevated throughout the day and nighttime.
The concern here is that residents who will occupy the proposed development in due course may be exposed to elevated noise levels from existing nearby sources, bearing in mind that noise levels associated with those sources may increase in the future, due to a planned increase in train activity. The World Health Organisation (WHO) has identified elevated noise levels as a major cause of health impacts throughout Europe, resulting in issues such as heart disease and sleep effects. The WHO recommends that the population exposed to elevated noise due to traffic and other sources should be reduced. This is the main objective of noise action plans issued by local authorities.
There is no Irish guidance on how to assess ‘inward impacts’. In the absence of any national guidance, impacts are generally assessed regarding ProPG Planning and noise: Professional practice guidance on planning and noise – New residential development, a UK document jointly issued by the Association of Noise Consultants, the Institute of Acoustics and the Chartered Institute of Environmental Health in 2017. ProPG sets out guidance on recommended internal and external noise levels at residential developments, taken from British Standard BS 8233. ProPG also includes guidance on the assessment process. Elevated noise levels due to existing sources may result in a requirement for acoustic treatment of building elements at the proposed residential development and ProPG recommends that any such treatment should be set out in an acoustic design statement.
MKO has undertaken environmental assessments for several residential developments, including LRD projects. Our Acoustics team has carried out inward noise impact assessments and prepared acoustic design statements as part of these assessments. Projects completed include a docklands development project in Cork, one of the largest LRD projects approved in Ireland. This project was particularly complicated due to the requirement to assess existing traffic noise from several roads, in addition to a requirement to assess future traffic growth, a proposed new road, a mooted bridge over the River Lee, the proposed Cork light rail project which will pass the site, as well as noise emissions from events at Páirc Uí Chaoimh.
Other residential projects have required an assessment of future motorways not yet built, and railway station activity (including noise from train horns on arrival and departure). Our Acoustics team has built up considerable expertise in inward noise assessments. This expertise is likely to be called on more and more as the country attempts to get to grips with the ongoing housing shortage.