Today, many existing buildings are being considered for renovation or restoration because the cost and carbon footprint may be significantly less compared to constructing a new building. These projects can also help tame urban sprawl and preserve the heritage of the built environment. The latest trend is the conversion of empty office buildings to residential. Renovation and restoration projects comprise a large portion of the work in the AEC industry. These projects are common in Philadelphia as the city is home to some of the oldest urban architecture in the country.
Renovation and restoration projects require an assessment of the existing conditions to identify issues that may affect the ensuing design and construction. These assessments are performed to evaluate the materials, structure, and infrastructure of the building. Existing buildings can also be assessed for acoustical deficiencies through testing. The types of testing performed in renovation projects are myriad; some of the more common are sound transmission tests for wall and floor/ceiling assemblies, measurements of intruding sound and vibration from building systems, and testing for exterior sources such as nearby road and rail.
In cases where a building is converted from non-residential to residential, noise reduction and impact sound testing of existing-to-remain demising assemblies is critical. For example, some office buildings are constructed with relatively lightweight composite decks (poured concrete over corrugated metal). While floor-to-floor sound isolation is considered in office buildings, there are usually no code requirements for air- and structure-borne sound transmission between floors, converse to residential buildings. For the latter, the International Building Code requires floor/ceiling assemblies achieve ratings of STC 50 and IIC 50, or field ratings of NNIC 45 and ISR 45. Measuring the air- and structure-borne sound transmission through an existing-to-remain floor/ceiling assembly is the first step to ensure the building will be code-compliant for its new purpose.
Further, some projects include spaces that inherently generate high sound levels (e.g., restaurants or bars with sound systems, fitness centers, etc.). These often occupy commercial spaces in mixed-use residential buildings. In the case of a bar, high sound levels with significant low-frequency content can be generated well into the night. Conducting acoustical testing of demising walls or floor/ceiling assemblies is valuable to develop a baseline for the existing condition and determine if upgraded assemblies are needed to keep sleeping residents happy.
Vibration testing is helpful in life science fit-outs. For example, life science spaces typically have equipment that needs very low ambient vibration levels. If a building is to be fit-out for lab space, it is valuable to measure ambient vibration levels so that the tenant is not left exposed to higher vibration levels than suitable for their equipment.
Performing acoustical and vibration testing for renovation and restoration projects is advised. Using measured data, consultants can determine the acoustical efficacy of an assembly and assist clients in developing recommendations. Doing testing during the design leads to better outcomes, more options, and lower price tags than being surprised after occupancy.