Red Way Self-Storage in Redmond, Washington has a design feature that makes it unique among self-storage facilities in the U.S. But its creation came about in an unusual way.
When local real estate firm, Nelson Legacy Group, decided to build a 578-unit storage facility, it discovered that the City of Redmond offered some very interesting “green” incentives. The program, called the Green Building and Green Infrastructure Incentive Program, encourages developers to incorporate green building and green infrastructure techniques into their designs. After reviewing a number of construction and landscaping options, the Nelson Group decided to go with a “Green Roof.” This allowed the company to get priority review status in the permitting process as well as add an additional floor to the building.
Amy Webber, Project Manager for Nelson, explained their choice. “We felt that, given the design of our building, a green roof made the most sense. We would be able to incorporate a unique design feature that not only benefited Redmond, but would also be of long-term economic benefit to us.”
Otherwise known as a “vegetated roof” or “living roof”, green roofs are typically comprised of either a layered system or a containment tray system. The Nelson Group worked with area eco-technology manufacturer, Columbia Green Technologies, and opted for the tray system due to its ease of installation and lower cost. The system consists of a series of interlocking and overlapping green roof trays that are spread out across the storage facility’s roof, amounting about 4,000 square feet of coverage. The 5” trays sit on top of the existing roofing material and came prefilled with soil and plants. Red Way’s installment came with sedum, a type of succulent. Sedum is a frequent choice for green roofs because it has a low water requirement, is drought resistant, has shallow roots, and adapts well to its climate. Other plants including moss, herbs or grasses are also used in green roofs.
Green Roof Benefits
There are a number of benefits to installing a green roof as well as some additional issues that crop up (no pun intended.)
Rainwater Management
As you can imagine, when rain hits a standard flat business roof, most of it is channeled off the roof onto surrounding hardscapes such as concrete sidewalks and roadways. This runoff picks up contaminants, which end up polluting water bodi
es. Green roofs mitigate this water runoff in a couple of ways. The soil retains a portion of the rainwater as well slowing down the flow of water that comes off the roof by 65%. In the process, the load that wastewater treatment plants must treat is lessened.
Longer Roof Life
The standard waterproofing materials used in commercial roof applications degrade over time due to sunlight and temperature and must be replaced every 15 to 20 years. With a green roof, the sunlight doesn’t reach the underlying roofing material, which means that the temperature of the roof is greatly reduced. This increases the life of the roof.
Reduced Energy Costs
While the amount of energy saved varies from building to building, green roofs can reduce the amount of energy that storage facilities use as the plants reflect sunlight that normally heats up traditional roofing materials. The plants also act as insulation during the winter months to block escaping heat. Facilities that have more roof surface area in proportion to their height are able to save more energy than taller, narrower facilities. Rick Bell, the manager of Red Way Self-Storage, concurs. “We’ve seen a nice reduction in our energy bills, especially during the summer months.”
Urban Heat Island Reduction
Urban Heat Island is a term used to describe urban areas that are often significantly hotter than the surrounding rural areas. This is due to all the paved areas like parking lots and roads, as well as clusters of buildings. All these surfaces retain heat and lead to increased energy consumption. Green roofs reduce the urban heat island footprint and related energy use.
Habitat Creation
A field of plants on a storage facility’s roof provides an excellent, new habitat for insects like butterflies and bees, as well as birds and other wildlife.
Drawbacks to Green Roofs
If this has got you thinking about installing a green roof for your storage business, there are also a few drawbacks to consider as well.
Cost
According the GSA (General Services Administration), a green roof will cost between $10.30 to $12.50 per square foot more than a traditional black roof. In addition to the installation costs, there will be ongoing maintenance that can cost approximately $.50/sq. ft/year. However, over a 50-year period, the savings gained through added property value, as well as in the form of stormwater retention, energy conservation and other factors results in a payback period of just 6.2 years.
Maintenance
As mentioned above, a green roof must be taken care of on a routine basis. These include doing routine inspections to remove debris and excess plants so they don’t block drain paths. Weeds will need to be removed so that additional sedum or other plants can grow. If the roof includes an irrigation system, this must be inspected to ensure it’s functioning properly. Red Way hires a local landscaping company to provide these services in addition to their standard grounds maintenance.
Access to the Roof
Should a roof leak occur, it can be difficult to quickly get at the underlying waterproof membrane. The green roof tray or layer system will have to be moved to access the point of the leak.
Unwanted Insects and Wildlife
Butterflies and hummingbirds sound great, but a potential exists for attracting more invasive species of both. There could be additional costs associated with removing these unwanted guests.
Are You Ready to Go Green?
The decision to put in a green roof is a complex one with both upside and downsides. But in Red Way’s situation it turned out to be a great thing. “We’re very pleased that we decided to do this. We feel like we’re contributing to keeping Redmond a great place to live and work.” added Webber.