Before I became involved in the world of green building I had never even seen an eco-roof. The first time I saw one it struck me that from a purely aesthetic or architectural point of view they create a sense of integration, or synthesis between the structure and the surrounding landscape, but that isn’t even the half of it…
I had the pleasure of interviewing Rosalind Haselbeck who along with Richard Alianelli form Building Green Futures, a San Diego company that specializes in living roof installation, here’s what she had to say;
BIGC- So what do you see as the chief benefits of a living roof?
BGF- The answer to that depends on your idea of ‘beneficial’ I would say the greater benefit lies in the many environmental aspects, such as the regained space for plant life (pollution and CO2 reduction) as well as mitigation of the urban heat island phenomenon mái tôn khung sắt. However for the individual property owner his immediate and personal benefit lies in the exceptional insulation, and temperature reduction/stabilization effects, as well as improved storm water management due to the absorptive qualities of the growth medium and plant life. Did I mention they are beautiful?
BIGC- So the benefits are personal, social, ecological, and aesthetic all at once. But how much does a living roof cost?
BGF- It’s really hard to put a dollar sign on it because your talking about not only say a couple thousand square feet of roof, but also a couple thousand square feet of landscaping. Is it more expensive then your average roof? yes, is it worth the extra cost? Definitely.
If your retrofitting you have to consider the added 2 to 5 times weight on top of the structure and making those changes can be pretty costly sometimes, but if your structural components can safely (and legally) handle the weight and your just adding waterproofing, drainage, growth medium and plants it can be as little as $8 to $12 a foot.
Aside from all the benefits I already talked about, it’s also worth mentioning that your green roof is going to last you at least 40 years and probably much longer. In Germany they have 80+ year green roofs that are still in good
BIGC- So were talking about a roof that will last you lifetime. That’s both an economic and ecological benefit right there. If this is the case why aren’t more roofs done this way?
BGF- Cost, quite simply. There is a higher initial cost, and the economic benefits are subtle and take years to mature. There’s only so many people willing and able to put out personal cash for social and ecological benefit.
BIGC- What about building codes?
BGF- There are a few that pertain. You need to meet fire safety standards, and demonstrate that your structure is capable of safely supporting the extra weight. Storm water drainage regulations also may apply.
BIGC- And maintenance?
BGF- That varies depending on type. Generally you would maintain your green roof twice a year, weeding, clearing drains, fertilizing- the same sorts of things you would do with your regular garden or landscaping…only on your roof.
So there you have it from the horses mouth. There are many factors involved in the world of green roofs. It all comes down to what is right for you and your budget. The good news is that there are now professionals out there like Rosalind and Richard who have made it their business to green the roofs of the world.