Colorado Real Estate Journal - February 4, 2015
Robert Frost famously said in his poem “Mending Wall” that- “good fences make good neighbors.” This philosophy obviously applies to demising walls in multifamily construction, and sound isolation in these buildings is given due consideration by building codes, designers and lawyers when things go wrong. This adage also applies to another building type where sound isolation is often overlooked: shopping centers. Many types of retail and commercial tenants can coexist happily in shopping centers because they are not especially loud or particularly sensitive to intruding noises. Other types of use are not well suited to shopping centers, but they can be made to work with the right planning and construction. Fitness centers are the most common offenders but there are many other types of tenants that can cause problems, some of which may be unexpected. Here are some problematic tenants that our firm has encountered: bars with live music (a growing problem with the increasing popularity of microbreweries); rock band style music instruction schools; dance studios; indoor shooting ranges; vet clinics, kennels or doggie day-cares with barking dogs; a tanning salon with noisy ventilation equipment; a golf store with an indoor driving range; a ski rental store with a ski tuning machine; and a chiropractor’s office with a special adjustment table. At the other end of the spectrum are tenants that are more noise sensitive and require greater separation from their n e i g h b o r s , such as spas or salons with quiet massage or treatment rooms. In either situation, the typical existing demising wall in a shopping center will probably not provide enough sound isolation. The first step to avoiding problems is awareness of the issue on the part of tenants and property managers when selecting a site. End-cap units are better for noisy or noise sensitive tenants because it limits them to just one neighbor and one demising wall to deal with. Single-story buildings with slab-on-grade construction help avoid sound transfer issues through floors and ceilings. Once a site has been selected, the condition and performance of the existing demising walls can be evaluated. An experienced acoustical consultant can help establish design criteria based on the tenant type, evaluate the existing conditions and make recommendations to meet the criteria. Some investigative demolition might be required to understand the existing wall construction. Acoustical field testing also can be performed to determine the existing level of sound isolation between spaces. Even a nonscientific test can be informative, such as playing loud music from a stereo in a potential space and listening next door. Site visits are recommended rather than working solely from drawings because there are often issues in the field that won’t be shown on the drawings. Spaces in shopping centers are frequently combined, separated and reconfigured over the years, leaving behind a patchwork of different wall constructions, filled-in doorways and other potential sound leaks. A site visit will help identify potential issues, such as walls that do not seal against a fluted metal deck, unsealed penetrations through walls, ductwork that passes between tenants and so on. Improving the sound isolation for a noisy or noise-sensitive tenant likely will require adding layers of gypsum board to the walls or even building a new freestanding stud wall next to the existing wall. Obviously this is much easier and cheaper to do before the tenant moves in, so it is vital that the sound isolation is addressed up-front and not after the fact.
In addition to demising walls themselves, other flanking paths can lead to problems. The intersection between the demising wall and a storefront window system often allows sound leaks. Free-weights hitting the floor in a fitness center can transmit sound and vibration into adjacent tenants, even through a concrete slab on grade. If there is no ceiling in the space, sound can flank through the exposed lightweight roof deck and HVAC systems. Typical exterior windows and doors do not provide much sound isolation, and sound transfer to the outdoors can sometimes bother neighbors. Although there are no building codes to regulate sound isolation in shopping centers, special lease language can be added to establish allowable levels of sound transfer from noisy tenants based on industry standards. This lease language can either use subjective, nuisance-based limits or objective limits based on decibel levels. For everyone’s protection, the latter option is preferable. Establishing decibel limits in octave bands gives the designers a target that they can design to, and it is easier to demonstrate compliance after completion. Subjective limits based on complaints are harder to enforce and can lead to more hassles for the property manager and the tenants. Sometimes tenants will even use noise complaints as leverage to disrupt adjacent tenants that they don’t get along with for other reasons. The party responsible for modifying the demising wall and meeting the criteria must be clearly established. In some situations, a new noise-sensitive tenant might move in next to an existing noisy tenant and the existing wall is inadequate. Who should be responsible for upgrading the wall in that situation? These decisions should be made before the lease agreement is completed. The cost of upgrading the construction should be considered when selecting a site. Good walls make good neighbors, but sometimes the best option is to put a noisy tenant in a stand-alone building with no neighbors at all.