Class MA permitted development allows the conversion of some commercial buildings to residential use, and is crucial to the delivery of much-needed housing in England. However, it is essential that development doesn’t impact on existing businesses, and to this end, the legislation makes an allowance for the Local Authority to request an assessment of the impacts of noise from commercial premises on the intended occupiers of the development.
This article explores the key sources of commercial noise, how surveys are undertaken, and the necessary mitigation measures to protect future residents from noise impacts.
Why Noise?
It would be easy to think that the noise assessment is just another tick in the box of red tape, but it’s important to understand the knock-on effect noise can have on residential occupiers and landlords.
Exposure to excessive noise has an adverse impact on health, well-being, sleep quality and ultimately, quality of life.
Residents exposed to noise are more likely to move home, increasing tenant turnover and associated costs for landlords.
Noise complaints can have a significant impact on businesses which were there before any residents moved in. Pubs and bars close across the country, due to noise complaints, and the Local Authority’s obligation to uphold them under the Environmental Protection Act 1990. Not only do these closures affect the businesses and their owners, but they also affect the wider economy and cultural life in our towns and cities.
Understanding Commercial Noise Sources
When assessing noise for Class MA developments, one of the key challenges is understanding the various types of commercial noise that can affect a residential environment. Some common sources include:
Retail and Hospitality Businesses: Shops, bars, and restaurants can generate noise from various activities, including customer interactions, deliveries, music, and equipment operation. Noise levels can vary depending on the time of day, with evening and night-time noise being particularly disruptive.
Industrial and Manufacturing Sites: Industrial premises near residential areas can emit continuous noise from machinery, loading bays, or ventilation systems. Even occasional bursts of loud activity can cause disturbance, especially at night when residents are more sensitive to external noise.
Entertainment noise: Noise from music venues, clubs and pubs playing live and recorded music can all have an impact on residents. In this situation, low-frequency bass sounds, and noise from patrons congregating or smoking outside are of particular concern.
Conducting a Commercial Noise Survey
A noise survey is typically required as part of the planning process for Class MA development to assess the potential noise impact on future residents. The survey process involves several key steps:
Initial Site Visit: An acoustician or noise consultant will conduct a site visit to assess the existing noise environment. They will identify potential sources of noise and areas of concern. This visit helps them understand the proximity of noise sources to the proposed residential development and the time of day when noise levels are highest.
Noise Monitoring: During the survey, noise levels are monitored at key locations around the site. This is typically done over a 1-2 day period to capture daytime and nighttime variations. The monitoring equipment records noise levels and the frequencies of concern, which can vary depending on the source. Additional, attending monitoring at specific periods of interest may be required for more complex sites with fluctuating noise levels.
Internal noise transfer: If commercial elements are still proposed in the same building, consideration needs to be given to these. Problematic adjacencies can include gyms, restaurants, bars and clubs.
Assessment Against Guidelines: The data collected is compared against relevant noise standards, such as those set by British Standards, Industry Guidance or local authority noise guidelines. This comparison helps determine whether the existing noise levels are acceptable for residential development or if mitigation is required.
Mitigation Measures for Residential Development
If the noise assessment identifies that commercial noise levels exceed acceptable thresholds, mitigation measures are required to protect future residents. These measures are often site-specific but may include:
Enhanced Building Fabric: One of the most common mitigation strategies involves upgrading the building’s envelope to reduce noise transmission. This includes thicker walls, sound-insulating materials, and high-specification glazing for windows. Double or triple glazing with air gaps between panes can significantly reduce the impact of external noise.
Improved Internal Sound Insulation: In some cases, improvements to floors or walls which separate commercial from residential demises may be required. Potential treatments include additional wall linings, or floating floors, both of which can assist in reducing commercial noise transfer towards acceptable levels.
Mechanical Ventilation Systems: Installing mechanical ventilation systems can allow windows to remain closed while maintaining fresh air circulation within the residential space. Closed windows can significantly reduce noise ingress, and these systems can provide a quiet indoor environment without the need for residents to open windows for ventilation.
Internal Layout Optimization: Another key strategy is to design the building’s layout in a way that minimizes the impact of external noise. For example, bedrooms and other noise-sensitive areas can be placed on the quieter side of the building, while less sensitive areas (e.g. corridors, bathrooms, kitchens) can face the noisier parts.
Conclusion
Commercial noise assessments are a crucial step in the planning process for Class MA permitted development, ensuring that future residents are not adversely affected by nearby commercial activities. By identifying key noise sources, conducting thorough noise surveys, and implementing effective mitigation measures, developers, architects, and planning consultants can navigate the noise challenges of these projects successfully.
Early engagement with noise consultants and local planning authorities can help streamline the process, ensuring that noise issues are addressed upfront and do not delay project timelines. Ultimately, managing noise effectively will enhance the quality of life for future residents and contribute to the long-term success of the development.
For a no-obligation chat about your Class MA conversion project, contact Timbral Acoustic Consultants, serving London and the Southeast.
Tony Trup – Founder
Timbral
Comments