Selling the concept of a green roof sometimes requires shattering a few myths.
Sustainability has been a strong selling point for residential homes for about a decade. Between increased and improved enviro-friendly building standards and a general desire by homebuyers to “do right” by the environment, it’s good to go green—and even better to quietly brag about it.
But while consumer literature, building competitions and on-site home tours gleefully point out obvious green components—such as low-flow showerheads, LED lights, Energy Star-rated appliances—and the less obvious, such as triple-pane glass, ultra-efficient insulation and recirculating heat pumps—there’s an item that presents itself nicely to the crowd and is more likely to get visitors to at least snap a photo of the house, if not flat-out beg for a key to the front door.
You might say that item—the green, vegetated or “living” roof—is a bit over the buyer’s head…and that’s a good thing.
To help remove, or at least clarify, some of the buyers’ and builders’ preconceived notions about green roofs, here’s a look at a few common myths and how to work around them with customers.
- All green roofs are the same, no matter what they’re called. There’s some truth here: By definition, a green roof is one that promotes plant growth as a tool for climate control and better air quality. But aside from that, there are three types of living roofs: “intensive” green roofs or roof gardens, which are accessible and may include larger plants and water features; “extensive” roofs, which are thinner, lighter and closer in appearance to a standard roof; and “semi-intensive,” which contain numerous different plant species, mostly native grasses and flowers.
- Green roofs are a new environmental trend. Contrary to this belief, green roofs have existed in some form since the era of
Ancient Greece. The modern vision of living roof appeared in mid-1940s Europe. Like so many items in the early baby boomer years, homes with green roofs became popular, but were in short supply.
- Green roofs cause structural problems. If a roof is going to leak, it’s going to leak no matter if there is grass or tile shingles up there. A properly designed living roof—one with a solid waterproofing member (something all roofs are supposed to have)—will be just as reliable as a regular roof. It may even better protect the structure, because the plants act as an extra barrier to wood-destroying ultraviolet light. The key problem could lie with the age of the roof when the garden goes in. Building codes for a new home take into account the impact of a green roof upon the structure’s designed load. But retrofitted green roofs are subject to varying requirements based on geography and the home’s original load capability.
- Only succulents can be used on a green roof. Water-storing plants are popular because they look good and can withstand fairly harsh conditions while up on the roof. But many types of vegetation can survive, particularly native grasses, if the right conditions exist. Irrigation is the key, as all plants need water (to some degree).
- A green roof is just some dirt on the top of the house. Strange how illogical this sounds, but for some builders and buyers, it makes perfect sense. A regular, ground-based garden is more than a couple shovels of dirt. There are times when a green roof doesn’t even need soil. It’s not as simple as mere potting soil—perlite or other porous materials are typical components. But it’s not an impossible task, either.
- Once a green roof is installed, the owner is on their own. Because they use various under-warranty building products, the same protections apply to green roofs as for any covered component inside the home. Every roof handled by a professional installer, green or otherwise, should have a service contract available for annual maintenance. How much it covers depend on exactly what the owner has planned for the roof.