GRP 001: The Top 10 Benefits of Installing a Green Roof

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In this episode: We discuss stormwater, aesthetic, urban heat island mitigation benefits of green roofs, and more

Kevin Songer and I are proud to present Episode 1 of the Green Roofs Podcast!  Please let us know your thoughts in the comments.  Any other particular areas you’d like us to cover?

Links Mentioned

  • Green Roof Industry Grows 28.5 Percent in 2010 – Reuters

GRP 001 Green Roof Benefits (right click and choose “save” to download mp3)

Raw Transcript

Dave: This is the Green Roof Podcast Episode 1. Welcome to the Green Roof Podcast, the podcast dedicated to helping you get your home or business on the road to a beautiful, energy-saving green roof, even if you’re just starting today. Hi everyone, and welcome to the first Green Roof Podcast, this is Dave Hilary.

Kevin: And I’m Kevin Songer

Dave: And today we are kicking off what we hope is the first of many podcasts where we talk about the benefits of installing a green roof on your home or small business, condo building or what have you, and talking about some of the ins and outs of the process.  We are doing this podcast to help home and business owners get educated about the benefits of green roofs and hope more people will be inspired to install them on their own homes or projects.

I just wanted to start off with a quick announcement, I was doing a little search on the iTunes store, and even though this is our first episode, the good news is we are already number one on iTunes, because we will be the only green roof podcast available, so congratulations to us for that!

Today we are going to start off with going through the top ten benefits of installing a green roof, but since this is the first episode, why don’t we step back a little bit and introduce ourselves.

My name is Dave and I live in Washington DC and I first got interested in green roofs because I live in a condo building, just moved in a couple years ago, and they have a green roof there, and I started doing a little background research and learned more and more about the benefits of green roofs, and got more and more interested in it the more I learned. Then about a year ago I started a website called which is the result of many interviews and research projects that I did on green roofs, and it’s a site dedicated to helping homeowners learn about green roofs and giving them information to get started.  And with me today is Kevin Songer, and I’ll let him say a few words about himself.

Kevin: Thank you, Dave, and good morning.  My name’s Kevin, my undergrad is in biology and I also have a law degree focusing on environmental law.  My wife Judy and I are south Florida natives and we have worked with plants for many years. We have worked with trying to grow plants on roofs for many years, and we are very excited about the wonderful potential green roofs have to offer, for many reasons which we’ll discuss today, and I’m looking forward to talking with Dave about it further

Dave: And I’m looking forward to continuing to hear those beautiful bird sounds in the background coming from Kevin’s end.  He’s got the perfect setting for recording this I think.

Kevin: You know, Dave, since we’ve started adding plants to the roof, the birds have come en masse, and it’s truly amazing to watch the hummingbirds and different types of migratory birds and butterflies, pollinators, come to the plants on the green roof.

Dave: Alright, so let’s move on to the main segment, which is going through the top ten benefits of installing a green roof, and I wanted to kick that off by mentioning a Reuters report last week that said – and we’ll have the link to this in the show notes – that the green roof industry grew 28.5% last year, in 2010, which just goes to show that more and more people are really getting on board and starting to discover the benefits, the enormous benefits that having a green roof can offer. And today we’re going to go quickly through the top ten of those, so number one is controlling stormwater runoff.

Kevin: And this is important, Dave.  What we have found and what we have seen based on field observations over the past years is that most green roofs will absorb all of the rainfall from a one inch event or less.  That means less runoff that carries pollution into our waterways, rivers, and streams, and certainly has a very positive ecological benefit.

Dave: Let’s move on to the second one.  And as we’re hearing the birds in Kevin’s background, number two is “providing a habitat for plants and insects, and wildlife”

Kevin: Absolutely, Dave.  You know we’ve got stormwater listed as number one, and many municipalities and cities and organizations highly recommend green roofs to control and attenuate stormwater.  However, in my opinion as a biologist, biodiversity ranks side by side with stormwater control.  You know we’ve created what I call “horizontal green” in the urban core.  We used to have vertical green – massive amounts of forests, trees, but today it’s the asphalt jungle rather than the native jungle.  And so with the loss of habitat that loss of vertical green, as I call it, wildlife has had to look elsewhere, and by restoring that vertical green in the form of green roofs back in the urban core, what we’re doing is bringing habitat back to cities, and that’s important, and I have a slogan Dave that says – I copied it, stole it – “if you build it they will come” and that’s so true.

Many of these species that we are seeing that are threatened or endangered now, they require green above 2-3 meters to escape their predators and once you build a green roof, what we’ve noticed here in Florida is that you’ll start to see the Florida Tree Frog and Florida Anoles re-appear, and that’s just the beginning because the Anole, which is a lizard, and the tree frog, you’ll have the other forms of wildlife that are up the food chain start to come to feed on tree frogs and green roofs, all the way up to eagles.  I’ve seen eagles circling.  We have a swallow tailed kite and an osprey that visit us on a regular basis, so providing habitat is a crucial important aspect of green roofs’ supporting biodiversity

Dave: Yeah, unfortunately, the green roofs that’s up on top of my building here in Washington does not bring in that much a diversity of lizards and birds, etc, but it is nice to just have that green space up on our rooftop deck area, and it just makes a lot more relaxing place and so there’s such a range of different types of green roofs, but they all provide some kind of a benefit in terms of having living things up there.

Kevin: No doubt.

Dave: So let’s move on to number three, carbon sequestration and oxygen production.

Kevin: For every 20,000 leaves that we have, nature pumps out enough oxygen for one person to breathe, so plants are crucial to providing oxygen, controlling air pollution in the urban core, and what better way to do it than on a green roof, and of course, plants, as part of the photosynthetic process in producing oxygen, they take in carbon, carbon dioxide and sequester that as plant biomass, so green roofs are doing the ecology of our cities’ urban core a huge favor by sequestering carbon and producing oxygen.

Dave: All right, let’s move on to number four, the fourth top benefit of installing a green roof “managing pests”

Kevin: Dave, we touched briefly on that talking about habitat but what we see is when the tree frogs and Anoles, the lizards, come to the green roofs, they eat termites, house flies, ants, and other pest insects, so it’s all part of nature’s plan for controlling exotic and invasive creatures.

Dave: I wanted to ask you this, have you ever had a situation where the green roof has become a home for pests and there’s been a problem with insects that are coming there?

Kevin: No, not really, Dave.  It’s just the opposite.  Some people may consider a lizard a pest, but most don’t and there relatively innocuous, harmless, and they’re fun to watch and of course they eat lots and lots of flies and ants and termites, so I have not seen a case where a green roof really does provide a home for exotic or invasive pests.

Dave: Alright, and so the fifth top benefit of installing a green roof is just the sense of beauty and sense of place that it can add, really in some cases re-claiming that rooftop surface as a place to hang out, place to enjoy nature.

Kevin: Oh no doubt, look at your website, the photos are beautiful, and just google “green roofs” they’re truly an amazing wonder of the world.

Dave: Moving on to number six, the sixth top benefit of installing a green roof is that certain types of green roofs, intensive green roofs, which have deeper soil – and we’re going to get into some of this in later episodes – but certain types of green roofs you can actually grow food and herbs and other edible plants up there.

Kevin: We love rooftop gardening, and it’s my opinion that one of the new frontiers for green roofs is going to be growing food, providing places to grow food.  Right now I’ve got a great little green roof that has black eyed peas and what I call Matt’s wild cherry tomatoes, they are little Tommy Toed tomatoes, and within a month we’ll have thousands and thousands of cherry tomatoes, so it’s a lot of fun to grow food on our roof, and it’s a good use of otherwise wasted space.

Dave: I just wanted to take this opportunity to plug one of my favorite restaurants here in DC, which is called the Tabard Inn, and if you google their name they have a rooftop vegetable garden and they harvest vegetables and herbs that they cook in their food, and I was over there for brunch the other day, and can tell you it is some fantastic stuff.  They have some really good pictures of their roof up there, so everyone should go check that out.

Now, let’s get down to the brass tacks economic benefits of green roofs, and the top seven benefit is the cost savings you’ll get because green roofs lengthen – by protecting the roof surface – they can actually lengthen, and in some cases double the lifespan of that roof surface.

Kevin: Absolutely Dave. I’m always amazed whenever we do maintenance on a roof, or do a change out on a green roof, once we pull up the roof, or the waterproofing layer, the underlying roof system looks like brand new, so we keep the ultraviolet rays off the roof, and there’s no telling how long it will extend the workable life of a roof system

Dave: Ok moving on to number eight, let’s talk about some of the energy savings that green roofs can bring, and how they can help you reduce your heating and cooling costs.

Kevin: Dave, this is exciting.  We just installed some thermocouples and are starting a temperature monitoring field trial for them on a number of green roofs here at Metroverde. And what we’ve seen so far, I’ve got it published on my blog, I believe there’s a link on your website to my blog, is that the asphalt roofs quickly gain heat during the day and jump 40-50 degrees hotter than the green roofs, so over time, it you look at that temperature curve you can see green roofs really do help moderate rooftop temperatures which, in turn, helps with the urban heat island effect and definitely energy savings within the building.

Dave: Yeah, I was checking out the research up on your site – do you want to give the name of your site again?

Kevin: its

Dave: And this is where Kevin puts up a lot of his research from green roofs that he’s installing with his company and, it’s really amazing to see the graph they have that shows how quickly those asphalt roofs heat up, and how having a green roof really reduces that curve and has a much more gentle heating up and cooling down throughout the day, and what that means for the bottom line is less money spent heating and cooling your home.

Alright, so benefit number nine of installing a green roof is the tax and zoning incentives that are available in many states and counties around the country

Kevin: This is exciting, Dave. For example, the city of Port Orange here in Florida has a one to one credit they allow if you don’t have the required amount of landscaping on your building site, you can put that landscaping on your roof. And this makes projects work, whereas they might not otherwise, so lots of benefits – check back I know you have a tab on your website that is a reference for some of those benefits, but check with your local authorities.

Dave: Yeah, we are going to have that link in the quick tip at the end of the show, which is a link to a site which has a very handy compilation of all the different zoning and tax incentives that are in place around the country. So make sure you stay tuned for that at the end of the show.

And now, let’s go on to number ten – so the top tenth top benefit of installing a green roof is that it reduces the urban heat island effect, and creates a microclimate around your building – so what is the urban heat island effect exactly?

Kevin: Dave, it’s just simply keeping the area cooler. Black asphalt roofs typically run 150-160 degrees Fahrenheit during a sunny day.  Green roofs 80-90 degrees, so your area is kept cooler, your building is cooler, and hence the entire city is cooler.

Dave: Yeah there’s some really fascinating research on that, we’ll have that in the show notes about how green roofs – even just one – can really change around, create a microclimate around the building and make the area much more pleasant place to live.

So, as promised those are the top ten, there are many more, which I’m sure we will cover in subsequent episodes, and they make a pretty compelling case for at least starting the research to see if a green roof might be right for your property or if you live in a condo building like me, staring to take to your neighbors and spread the world a little bit.

Let’s move on to the quick tip, which I mentioned earlier. If you go to a page on my site which is and look under “websites” at the end, there’s a link to a site that gives you a round-up of all the different legislation, policies and tax incentives for installing green roofs in your area, so you can go and check to see what might be available to you wherever you live.

Kevin: Green roofs are addictive, they really are.  Once you start, it’s hard to quit.  There are just so many benefits, and I look forward to discussing, vetting through some of the ups and downs of green roofs with you in future podcasts.

Dave: Yeah, and I hope you all enjoyed the podcast, this is it for us for today, but we’d like to encourage you to please leave us a comment on the post and let us know what questions or topics you’d like us to cover in future segments of the podcast. And make sure you tune in next time where we will talk about the different types and variations of green roofs.

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