Designing for Residential and Hotel Uses in Noisy Locations
What do thrifty investors, industrial reuse, and affordable housing have in common? Railroads!
Ok, perhaps not railroads themselves, but certainly proximity to active rail lines. Recently, we’ve seen projects from California, North Carolina, Florida, and Washington all located adjacent to active rail lines. As demand rises, developers and city planners look to utilize vacant or abandoned lots and buildings, often in the noisiest part of town. Let’s take a look at how we guide the design of projects near rail lines, and the biggest pitfalls we’ve seen on similar projects.
How Loud Is It?
“We’re pretty sure those tracks aren’t in use.” Fortunately, this client gave us a call before charging ahead with design. The owner and project architect had been on site all day, multiple days, and hadn’t seen or heard any trains. Why? All eight, yes you read that correctly, eight, trains passed the site between 10pm and 6am. The building façade was less than 100-feet from the tracks, with nothing but parking lot in between.
The first step in addressing a noisy site is to determine just how noisy it is. With a combination of on site 48-72 hour measurements, noise level calculators, train schedules, and our library of measurement data, we can determine both the overall noise level on site, as well as what peak values can be expected from loud events, such as a train horn (or eight of them).
How Quiet Does It Need To Be?
Well that depends… What will the space be used for? Commercial applications can tolerate more noise than residential. Market rate and luxury tenants expect a quieter environment than affordable housing. The Department of Housing and Urban Development (HUD) sets requirements for affordable housing, and extensive industry and academic research has established guidelines for maximum noise levels in market rate and luxury applications.
In locations with specific loud events, such as a site near an at grade railroad crossing where trains will sound their horn, additional sound isolation should be provided to lower the peak noise levels to a level that will not be as disruptive.
Getting From A To B
“So, we are going to use windows just like the building’s original ones, from when it was built as a warehouse in 1903.” Typically, if a site is noisy enough to be worried about, it is noisy enough to require upgraded windows, not just historical 1/8-inch float glass or simple thermal panes.
To reduce the exterior noise down to the target interior level, the exterior envelope as a whole must provide the desired level of sound isolation. Sounds simple, but different building elements provide different levels of sound attenuation. Typically, windows and doors provide much less sound isolation than walls. The weakest element will control the overall sound isolation, so upgraded windows are often a must. The windows’ sound isolation performance may need to get pretty close to the overall performance level desired. This often requires dual pane windows and laminated glass.
So We Can’t Build There?
No, not exactly. While there are plenty of sites that we would advise against, there are mitigation efforts that can make bad sites workable. It is important to note that these efforts don’t just mean walls and windows. On nearly all sites with a noticeable noise source this means mechanical ventilation and inoperable windows. On sites with very high noise levels from all types of sources (think Steve Martin and John Candy’s movie “Planes, Trains & Automobiles”) this means changes to floor plan, building layout, and potentially the omission of features such as balconies or the addition of sound walls. It is possible to make that site work, but it means thinking about the noise as early as the conceptual phase and working with an acoustical consultant who can guide the evaluation and mitigation of site noise.
Please reach out if you need assistance with Acoustical consulting. We can also help with your next AV/Technology or Lighting designs.