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Sustainable Urban Rooftops Urbanstrong
86 Plays4 years ago
Conversation highlights
- It doesn’t feel right that with we have so little opportunity to connect with nature here given the huge percentage of our lives we spend in dense urban centers.
- Green roofs clean and cool the air, sequester carbon and provide rooftop habitats for birds, bees, bats, butterflies, and much more.
- Farm-to-table is great but roof-to-table is even better
- Green roofs perform multiple functions with societal, environmental, building operations, and mental health benefits, all simultaneously.
- Building owners should be thinking of their rooftops as buckets instead of lids, because there's money falling out of the sky.
- Solar panels lose operating efficiency when the ambient air around them gets too hot but Plants cool the air around them through through evapotranspiration so when you install solar panels directly on top of green roofing, the plants cool the air underneath the solar panels and help them to produce more electricity
GUEST / ALAN BURCHELL / PRINCIPAL, URBANSTRONG
HOST / MATT MORLEY / WELLBEING CHAMPION
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Transcript
Introduction to Green and Healthy Places
00:00:10
Speaker
Welcome to episode 41 of the Green and Healthy Places podcast, in which we discuss wellbeing and sustainability in real estate, interiors, and hospitality. I'm your host, Matt Morley, a wellbeing champion and founder of Biophilico Healthy Buildings.
Guest Introduction: Alan Burchill
00:00:26
Speaker
This week, I'm back in Brooklyn, New York, talking to the principle of urban strong, Alan Burchill.
Trends and Benefits of Green Roofs
00:00:32
Speaker
Alan trained as a mechanical engineer, is a background in HVAC, aircons, plumbing systems, and then slowly migrated across into renewable energy and eventually found his way into vegetative rooftops. So he has a very technical hands-on take on the practicalities of getting this stuff done. Urban greenery solutions, in other words. We discuss trends in rooftop gardens in New York in the wake of COVID lockdowns.
00:00:55
Speaker
the well-being benefits of connecting with nature on a rooftop, as well as the economic and environmental benefits of a green roof from a range of different stakeholder perspectives, occupants, developers and even city government. We look at green roofs and stormwater management, new legislation pushing for green and solar rooftops on new build projects in New York and the opportunities that rooftop food production offers for the future. Arguably though, my main takeaway from this conversation is the interconnectedness of benefits
00:01:23
Speaker
once one brings nature back into the city via a green roof. They deliver effectively multiple functions at once even if the building owner may not actually be interested or even aware of half of them. It's a valuable insight and Alan has a really positive upbeat message to spread on this topic.
Alan Burchill's Professional Journey
00:01:40
Speaker
So enjoy the episode, hit subscribe if you want to receive next week's download as well. Here's Alan Burchill.
00:01:50
Speaker
Alan, it would be great to hear a little bit of your background and how you came to be the principal at Urban Strong, what your professional career has looked like to date. Sure thing. First of all, Matt, thanks for having me. It's a real honor to be on the show. So formally, thank you for having me here.
00:02:08
Speaker
So my career, I won't go too far back. I'll just, I'll try to give you a bit of a highlight reel. Um, so formally, you know, trained in undergrad as a mechanical engineer and a lot of mechanical engineers who don't know what they want to do coming out of school university wind up getting sucked into working for, uh,
00:02:29
Speaker
consulting firms, specifically engineering consulting firms. So I worked at a mechanical electrical consulting firm who did all kinds of work for different building types. And I specifically was designing
00:02:41
Speaker
HVAC systems, plumbing and piping and fire suppression systems for banks, condos, restaurants, you name it. That was a little bit dry. I was a little bit young. I was kind of living for the weekends and I realized I needed a bit of a change. And I didn't know this term at the time, but what I was looking for was a career path with a vein of
00:03:04
Speaker
some sort of social responsibility going through it. So I went back to school, I did a business degree and found the world of renewable energies and within the world of renewable energies, wind energy was most appealing to me. It had the, you know, the
00:03:20
Speaker
dynamic nature of wind turbines that appealed to the mechanical engineer to me, but then the renewable green energy component that appealed to the outdoorsman and the environmentalist in me. So that felt like a great fit. So I worked in that industry for years. I worked for a Spanish wind turbine manufacturer called Gmesa at their North American corporate headquarters just outside of Philadelphia. And so, yeah, worked there for several years.
00:03:47
Speaker
in the sales department and I was running sales for spare parts and repairs on wind turbines across the country.
Importance of Urban Greenery
00:03:59
Speaker
Eventually then I wanted to get further entrenched in the world of sustainability and I started studying up on the space and then I found the world of green vegetated rooftops and that really checked a lot of boxes for me because They I'm I'm a big city as much as I love the outdoors. I really like big cities I've had the blessed opportunity to live in several around the world Toronto Barcelona London Shanghai Philadelphia now New York and I
00:04:29
Speaker
It never sat well with me, the idea that in order to connect with nature, someone had to get out of the city, like go up to a cabin, a cottage, lake house, go to the beach. It didn't feel right that with all the huge percentage of our lives that we spend in dense urban centers, that there's very little opportunity to connect with nature.
00:04:50
Speaker
And then I had a side interest in architecture, interior design, and then every cubicle or office I've ever had or apartment has always been chock full of plants. Now I never imagined my career path would involve plants. It makes me sound like a florist and that just wasn't something that
00:05:06
Speaker
If you had told 25-year-old Alan that he'd be a florist when he grew up, I just wouldn't believe you. Anyhow, I found the world of vegetated rooftops and I realized that these systems are multifaceted in their benefits and that they offer to building owners, to people battling climate change, to municipalities looking to
00:05:26
Speaker
combat or mitigate a lot of issues that plague modern day dense urban centers. So they checked all these
Urban Strong's Integrated Services
00:05:32
Speaker
boxes. And so I went into the world of green rooftops. I first naively thought, great, I'll start my own green roof company. And then I realized very quickly that there are already several people doing this design build firms in New York City doing exactly this. So I couldn't really go from never having heard of green roofs to being competitive in the New York City market in a short span of time.
00:05:54
Speaker
So instead I decided to insert myself in the market with the only tools that I had with me other than enthusiasm for Greenroofs and that was engineering system sales and so from my previous career. So I partnered with a, I started basically offering third party freelance business development or a really dirty word for it would be brokerage of Greenroof sales. So I would go out and beat the streets and look for clients and building owners
00:06:22
Speaker
sell them on the idea of green roofs, and then connect them with green roof design build firms, collect a bit of a commission, and then move on from there. That evolved very quickly into offering the same for rooftop solar, living wall gardens, and then over the years, it's grown and grown because we're facing, you know, a lot of these people's ideal clients, building owners, condo and co-op boards, you know, multifamily buildings and whatnot.
Impact of COVID-19 on Greenery Demand
00:06:50
Speaker
And they have a range of needs. Either they want a lush green amenity space, or perhaps the local city ordinances are mandating that they either do green roof or solar up on their roof. So anyhow, I offer them a range of consulting services, and then the full range of design, build, and or long-term maintenance for green roofs, living walls, rooftop solar, advanced stormwater systems for rooftops, and all of the above.
00:07:18
Speaker
So you end up offering effectively a kind of vertically integrated service and product offer which makes complete sense I think in the end because once someone sort of jumps into bed with you then it's natural that they should want a complete service offer from you. You mentioned New York, we can hear background noise from New York which sounds brilliant but like tell me what's happening at the moment there, what's the scene looking like, how have you seen it changed over the last
00:07:44
Speaker
few years and where do you see it going? What's happening there specifically in your location, your city, your hometown?
00:07:51
Speaker
Got it. So one thing I've definitely seen change. I mean, COVID cannot be ignored. It probably finds its way into every episode of your podcast in one way or another. How I've seen it specifically impact our industry, our multifamily residential co-op condo buildings and whatnot made those folks who perhaps had declined to move forward with a rooftop amenity space, a green rooftop amenity space in the past.
00:08:17
Speaker
found themselves calling us back up during COVID saying, OK, we get it now. We really now see the value in having a private rooftop garden space exclusive for residents in the building where they can access without having to go out into public. And we used to tout it as, hey, wouldn't it be nice to take a mug of tea up from your own personal apartment and just walk up the stairs or take the elevator to your own roof?
00:08:46
Speaker
you know, rather than having to go out to a city park, and they really felt that during COVID. So demand for outdoor terrace opportunity for green space has really increased from that perspective. Similarly, with everyone quarantining and working from home, more so than ever, people are critically evaluating their indoor surroundings and asking whether how
00:09:10
Speaker
this space contributes or maybe negatively affects their mental health. And so people have then are now starting to click into realizing, you know, plants are a great prescription for
Economic and Environmental Benefits
00:09:22
Speaker
the quarantined. And so people were looking for ways to bring greenery into their home, whether that's on a terrace in the form of a little green roof on the rooftop is a green roof or indoors as living walls, because you can only
00:09:35
Speaker
fit so many potted plants on your window sill or on your bookshelf, and then you run out of space. And if you want to go heavy with the greenery, you've only got so much floor space, but a lot of people have excess wall space, so you could build a living garden wall, really lush out, green out your indoor space, but not consume that valuable footprint real estate. And in terms of then, since that's
00:09:57
Speaker
Primarily the, let's say the social angle or the sort of mental wellbeing and the human aspect to it. I think we can all connect with that at a very sort of primal level. And then there are also economic and environmental benefits too, right? So perhaps sort of on a slightly wider perspective, how do you see those two factors playing into a decision-making process around installing one of these green roofs?
00:10:21
Speaker
Sure. So it would, it really depends on which stakeholder we're talking about because the city, like the New York city government, they are motivated for people to build green roofs for one host of reasons.
00:10:35
Speaker
and then private property owners, you know, building owners are motivated to build green roofs for a very different set of reasons. The thing I like before we get into those reasons about that situation though is with green roofs, regardless of which set of benefits you're most interested in and what's motivating you to buy the green roof, you get the other benefits. It's sort of like if you and I buy the same Swiss Army knife, you may be buying it.
00:10:59
Speaker
for the Phillips screwdriver and the wine opener and the saw, and maybe I want it for the tweezers and the scissors, but we get each other's tools because we're buying the same Swiss Army knife. So that's a very long-winded way of me saying, here's another anecdote. I'll say, for example, most green roofs being built in New York City, if we're being perfectly honest, are by wealthy people who are building these lush green oases, terrace or rooftops, because they want a calm green natural space
00:11:30
Speaker
over top of the city where they can drink, you know, rosé wine spritzes with their friends and just relax. As the environmentalist, I like green roofs because they're managing storm water, sequestering carbon, providing habitat and food for a migratory and local species and whatnot. But they don't, whether they care about that stuff or are aware of that stuff or not, they're getting, they're providing the city and the general public all of those benefits when they build their swanky rosé sipping rooftop garden oasis.
Stormwater Management in NYC
00:12:00
Speaker
As far as direct benefits, and this is how I've definitely seen things change in New York dramatically. Speaking from the perspective of the city, many of the older, larger North American cities are battling a stormwater management crisis.
00:12:17
Speaker
And that's because our sewer systems were designed 150 years ago when there was only a fraction of the pavement space and everything was, you know, the island of Manhattan was mostly farmers fields above the absolute downtown, so rain didn't really go into the sewer. It all landed on the open green space. And 150 years ago, there was only a fraction of the toilets, now, you know, population of 9 million.
00:12:40
Speaker
a lot more toilets than there were 150 years ago. So there's nowhere for the rainwater to go except hitting pavement going into storm drains or hitting rooftops and going down the scuppers into the sewer drain. And there's way more wastewater being generated and then being sent through indoor plumbing directly down into the sewer. In several North American larger cities on the East Coast, the older ones at least like Toronto, New York, D.C., Philly, Chicago, we have what's called a combined sewer system.
00:13:08
Speaker
That basically means it's a single pipe system. So rainwater and toilet water all goes down into the same pipe. On a dry day, we can still manage to process all of it at the wastewater treatment facility. But in New York City, for example, it only takes one-twentieth of an inch of rain. That's about between one and two millimeters of rain.
00:13:30
Speaker
is all that's required to max out the city's wastewater pipe going down to the wastewater treatment facility. And so the excess, rather than having it pushed back up through people's toilets and flood their homes or pushed back up through the storm drains in the streets and flood the streets, the excess is just allowed to flow over through what are called combined sewer overflow points. And there's 460
00:13:54
Speaker
these combined sewer overflow points lining the New York City Harbor and people put really really gnarly stuff down the toilet way worse for our health than feces and urine. We're talking like you know illicit drugs, expired birth control medication, cancer medication, broken glass batteries. I mean people are animals and they put awful stuff down the toilet and the privacy of their own home and all of that is flushing out
00:14:21
Speaker
into our local waterways here in New York and the local waterways of all the other cities I just mentioned to you, whenever there's more than
00:14:28
Speaker
two millimeters of rain in the city or, you know, a one-twentieth of an inch. So that is a major, major, major problem. So cities are being fined at the federal level to clean it up. And so now the options are, you know, tear up the sewer system and put a new one in, which is preposterous. That could never possibly happen in New York or, you know, put down more parkland. But, you know, every inch of New York City's developed, you can't
00:14:54
Speaker
tear up a city block and put a new park. But nothing says these parks have to be at grade level and nothing says these parks have to be continuous. They can be, what's the word, distributed parks cut up into tiny places and put up on top of the rooftops where the rainwater lands. And so basically green roofs, mini little rooftop parks act as sponges
00:15:18
Speaker
They absorb the rainwater right where it lands on the roof. Half the water never makes it off the roof because it's just used for photosynthesis and evapotranspire by the plants up into the atmosphere. And the rest of the water takes its time to percolate through the system.
00:15:33
Speaker
much like a coffee machine, if you will, a coffee percolator, and it peakshaves the worst effects, the worst stresses during a big rainfall event on the sewer system. So that's just stormwater management. There's relocating into details, green roofs clean and cool the air.
00:15:48
Speaker
They sequester carbon, they reduce the footprint that urban centers have on the local ecology by providing rooftop safe habitats for migratory and local birds, bees, bats, butterflies, and whatnot. So there's a whole host of environmental reasons why cities like green roofs. They also like rooftop solar here in New York City for reasons that should be obvious by now.
00:16:11
Speaker
So a big change that I've seen recently was as part of New York City's Green New Deal or the Climate Mobilization Act, I and a few other people
NYC Legislation on Green Roofs
00:16:20
Speaker
testified at City Hall back in January of 2019 in support of a few key pieces of legislation. They were all unanimously passed, but a big one that's going to have a major impact on the skyline of New York City, specifically its rooftops, is something called Local Law 9294.
00:16:37
Speaker
and this basically mandates that all new construction and certain retrofit projects must install either a green roof or rooftop solar. There's certain exclusions if it's too sloped or if you don't have the structural capacity or if it's too shady or whatnot, but nonetheless, this is going to have a massive impact in driving change to the greening of New York City's rooftops. So this is a big change. It only really came into effect about a year ago
00:17:05
Speaker
And so this is for all new building permits. And as buildings start to go up, you're going to see the number of green roofs and solar installations in New York City utterly skyrocket. So that's an exciting, exciting change here. That's the city in a way laying out its vision for the future in terms of how roofs need to play a functional role in protecting the city itself and the urban landscape from climate change, from
00:17:30
Speaker
negative impact that we're bringing just by building cities of this absolutely i mean rooftops are sort of like the front line both if you're talking about sunlight or if you're talking about raindrops whether you're talking about sorry whether you're talking about the photons from sunlight or the raindrops from clouds one of the first things they're hitting is the rooftops in the city so that's their frontline defense to either
00:17:50
Speaker
capture these photons and use them to generate electricity. I may also add that as you capture these photons on solar panels, that means they're not hitting the roof membrane and not heating up the membrane and not sending all that latent heat baking down and driving up air conditioning bills in the summertime. Green roofs do the same thing. The leaves of plants are actually the plant's solar panels because that's where they get their food energy, if you will, from the photons and use it to photosynthesize and
00:18:18
Speaker
grow more plant matter, but again, they're intercepting those photons and preventing them from hitting the roof membrane. And then the raindrops as well. I mean, the plants can sponge up and act as the first line of defense. In New York City, less than 0.01% of rooftops are developed in any way, and it's a very much
00:18:38
Speaker
out of sight is out of mind situation.
Potential of Rooftop Green Spaces
00:18:41
Speaker
And I think it's because people, not too many people exist in New York City in a way that they look down on other rooftops. A lot of people are just milling about down at street level. And so you kind of forget about groups. You don't notice them. So, which I find really odd because New York City is like a lot of other really expensive urban centers around the globe. It's absolutely obsessed with real estate, the cost per real estate, the cost per square foot to buy or own or rent or whatnot.
00:19:08
Speaker
And yet no one does anything with their rooftops. They max out every square centimeter, every square inch of their apartment to fit one more picture, one more piece of furniture, one more plant, yet buildings, rooftops are completely undeveloped or at least less than 0.01%. I find that odd, but now that's changing. The city realizes it's a massive wasted opportunity, wasted infrastructure to solve many, many problems that plague urban centers around the world.
00:19:38
Speaker
Yeah, so they're turning their own attention to rooftops very much. And we sometimes see a rooftop used for an element of food production, whether that food is then consumed by those living in the building or whether it's distributed or handed out to those in need in the local area, whatever it may be. But do you see that as perhaps
00:19:58
Speaker
you know, an exception rather than the rule when it comes to how to utilize a rooftop, or is there real benefits there in terms of making a more resilient city so that there's more local, like kilometre zero production happening onsite around NYC, around Manhattan, or is it the equity play, the sort of social equity piece that's most interesting for you when you see examples like that? It's, you know, to be honest, Matt, it's a bit of everything. They're all, it's a definite opportunity.
00:20:27
Speaker
The all of the reasons that I've mentioned to you about why city municipalities city governments like green roofs. It doesn't matter whether the plants at the very top layer of the green roof are ornamental.
00:20:41
Speaker
amenity space plants that are there just for aesthetics or if they're there as food crops, they're still performing all of the critical functions and offering the same benefits that as every type of green group does in terms of stormwater management, sequestering carbon, insulating buildings, providing habitat for species and whatnot.
00:21:01
Speaker
And so, yeah, I think urban food production on rooftops is a massive, massive opportunity for cities around the world. It combats many problems, either social justice or environmental that plague urban centers as well. So I think it's a huge opportunity. We encourage
00:21:19
Speaker
all of our green roof clients to dedicate at least some portion of their green roof to be a little urban agriculture plot. Now, that's, you know, this can take many forms. My neighbors, I mean, as I'm looking at the window right now, my neighbors are Brooklyn Grange. And for people that don't know, that is a, that's one of the largest rooftop farms in the world here in New York. So that's a fully commercial operating farm on top of a commercial building, but there's plenty of
00:21:48
Speaker
green roofs in a city where maybe it's an amenity space on a multi a private you know residential building and maybe the residents will ask us to dedicate you know a few square meters off to one corner for like a little tomato plant growing a little plot there or something like that but yeah there's plenty of opportunities to create sustainable green local jobs and then produce food that's either used if it's in a commercial entity like for the
00:22:14
Speaker
the building tenants themselves or can be sold or distributed or donated to the local community and it definitely speaks to improving the resiliency of the city because
00:22:26
Speaker
you know any any city many most cities are trucking in importing their food from other cities or other countries and the more that you can grow domestic domestically what am i saying the more that you can grow locally uh the less reliant you are on other cities for your food production so you're certainly becoming more self-sufficient in that regard but also there's you know the transmission emissions i mean if we're trucking
00:22:51
Speaker
you know fresh fruit in from California it's got to come all the way across it's not quite as fresh by the time it gets here it's also expensive to truck it in and there's certain carbon emissions related to all that transportation to ship it over so all of that is eliminated when you can be growing right on the roof i mean farm to table is a great movement but roof to table is an even better movement
00:23:16
Speaker
So the key point I'm picking up there is that it's not one
Native Plants and Local Biodiversity
00:23:20
Speaker
or the other. It's not only one thing or only something else. In fact, actually, the way these natural roofs work is that they can do multiple things at the same time. So you're not neglecting, for example, the promotion of improved biodiversity by adding an agricultural component to your green roof. In fact, it's layers of benefits in a way rather than one to the exclusion of anything else.
00:23:44
Speaker
I totally agree. I keep coming back to the Swiss Army knife analogy. I mean, the green roofs are performing multiple functions at once. There's societal benefits, environmental benefits. There's building operations benefits, mental health benefits, you name it. And they're performing it all simultaneously and passively, whether we like it to or not. Again, the people who are, if a wealthy couple just wants to build
00:24:14
Speaker
a fancy rooftop garden amenity space just for their own family, let's say, those plants are still sequestering carbon, cleaning and cooling the air, you know, thermally insulating the space, which would improve their energy efficiency and probably reduces their reliance on fossil fuel power plants. And again, maybe they don't care about all of that. Maybe they're not aware of it. Maybe they don't care. For a lot of our clients, we will, if in
00:24:43
Speaker
In lieu of any input from them around plant species selection, we are going to lean heavily towards favoring native and adaptive plant species so as to improve conditions for local and migratory species.
Solar Panels vs. Green Roofs
00:24:59
Speaker
So in a sense, then some of that responsibility comes to you. When there's a little bit of extra leeway around deciding exactly which species go in, then you can sort of dial that up.
00:25:09
Speaker
Yeah, if anyone wants to deeper dive on this topic, there's a book called nature's best hope and it's by Douglas Tallamy t a double a Amazon Mary why and he speaks extensively on the topic of the
00:25:23
Speaker
urgent need for people when they're doing landscaping in their homes, around their buildings, whether it's on the rooftop or at grade, using native plants that are native to the area or adaptive rather than bringing in these plants that are not native to the region and maybe are going to require quite a lot of resources in order to keep them alive in whatever your respective microclimate is. And then also they could be potentially, you know,
00:25:53
Speaker
The concrete jungles are creating these like, these blot out, I'm lost for words here, these scorched earth kind of patches all around the globe where nature can't really thrive or birds who maybe after hundreds of generations of programming are used to flying that migratory pathway and they're used to touching down there to rest or seek food or
00:26:21
Speaker
or procreate, they can't do that now because it's all some urban sprawl has created a concrete spread. And so anything that we can do to recreate what they're used to having there as far as greenery that houses the bugs that they want to eat or provides habitat for them to build nests or rests, anything we can do to help with that will reduce the impact that our urban centers and urban sprawl are having on the local ecology. So within
00:26:49
Speaker
the realms of a natural intervention on the roof. I think it's very clear that there's this sort of multi-pronged, almost like a spider diagram of all the various different benefits. But when you zero in on say solar panels, for example, where you're really integrating a technical component, perhaps more of an engineering angle,
00:27:08
Speaker
there the benefits presumably reduce and focus more on the environmental impact, the economic play, rather than nature. So when you're proposing those, what are the conditions under which you would typically propose solar panels to be in the mix or to be the dominant force on any given rooftop? Do you mean that to say instead of a vegetated roof? Yeah, so it's a great question. It's actually, I'll give you the highlight reel, but it's actually such an involved answer sometimes and it's
00:27:38
Speaker
It really needs to be determined on a case-by-case basis that years ago we realized we were giving away so much upfront free consulting for buildings because they would call up and say, hey, we've got a roof. Should we go green roof or solar? We see that you offer both, and there would just be such an involved process to determine which is best for them and their goals and their budget.
00:27:58
Speaker
and their dreams for that building that we now offer it as a branched-off consulting service in advance of either building them a green roof or a solar. It's a discovery process, if you will, or a service. But on a really high level, there's a few things. We can either go process of elimination, like a lot of time people will call up saying they want a green roof, and I start asking them questions.
00:28:21
Speaker
And one decision or one element or another could kill the green roof project. And the green roofs, they get killed. They die on the vine all the time. And then that leaves them with what they feel is a useless rooftop. And I say, well, hang on. There's always solar. When it comes to solar, money is falling out of the sky and solar panels are buckets. So your roof is far from useless. It can be a great source of passive income for your building, especially now that it turns out that you can't build the green roof that you wanted for whatever reason.
00:28:51
Speaker
So, for example, solar panels are quite lightweight. They're really only about five pounds per square foot. I'll let you translate that into kilos and put that in the show notes. Compared to, say, green roofs, which at their lightest are going to be, say, 15 pounds per square foot, but they get heavy very quickly. As a little rule of thumb, green roofs tend to weigh six and a half pounds per inch of depth per square foot.
00:29:21
Speaker
And at the minimum, the average green roof is 3 to 4 inches, so we're talking at least 18 to 25 pounds per square foot compared to solar that's 5 or 6.
Cost and ROI of Green Roofs
00:29:32
Speaker
Now that, to be clear, that's when the green roof is fully saturated or holding the most amount of storm water that it's designed to from an engineering perspective, but that's not including
00:29:45
Speaker
if it's meant to be a public amenity space, or just an official amenity space listed on the building certificate of occupancy. Basically, are you officially decreeing to the city that this is an amenity area for the building? Because the moment you do that in New York City, for example,
00:30:03
Speaker
you have to show that you have structural capacity at a hundred pounds per square foot if people are going to be walking around up there. So if you have a deck and people are going to be congregating there with any regularity, and then you have greenery around it and at your green roof, you're going to need at least a hundred pounds per square foot in the areas where the people
00:30:20
Speaker
congregate. And a lot of buildings don't have that. And a lot of building owners will say, well, hang on. If we can't use it as an amenity space, we don't want it as a green roof. And then that's frequently what kills a lot of greener projects in New York City. So then you're left with solar.
00:30:39
Speaker
I'm sure it's a question you're asked often by clients, no doubt, far earlier in the process than you might like. But inevitably the economics of all this has to come into play at some point. There are some big numbers involved, I know, but why don't we just have a quick overview, if we can, of the financial side and what we're looking at in terms of these green roofs and how perhaps different sizes, if it's shapes or densities or
00:31:05
Speaker
But planting strategies can all affect exactly how much the overall budget equates to. So that really ranges. I mean, it just depends on so many different factors. It's hard to speak absolutely about this because it changes even within New York City, the exact same green roof technology because beneath the plants there's a wide array of technologies.
00:31:27
Speaker
the exact same green roof technology in the exact same neighborhood of New York City on two very different buildings could cost $17 a square foot or it could cost $60 per square foot. I'd say the two biggest factors are economy of scale is massive for green roofs because with a lot of construction projects, my mobilization is a big one. So to make an extreme example, if you're mobilizing a crew, maybe you're getting a crane permit
00:31:56
Speaker
You can put design hours, and just to make an extreme, absurd example, if you were doing all of that for one square meter or a one square foot green roof, no, just to make an example, right? All those costs per square meter, per square foot would be outrageous. But if the exact same designer, same crane permanent, same crew mobilization, same design hours is allocated over
00:32:20
Speaker
500 square meters or 100 square meters or 500 square feet, 1,000 square feet, you can obviously see that that cost per square foot is going to drop like a stone.
00:32:28
Speaker
Similarly with solar panels, but sticking with readers, the other thing that could really drive it would be access. I mentioned there a second, cranes. If we can crane the material up, that's one efficient way to get a lot of material up to the roof very quickly. However, depending on what part of New York City that you're in, that crane can cost anywhere from $5,000 a day to $40,000 a day.
00:32:52
Speaker
Depending on the permitting, do you have to block off the road? Do you have to build these protective sidewalk sheds so that people can still walk along the sidewalk underneath? So the crane costs, cranes can either save you a lot of money with efficiency or kill the project.
00:33:06
Speaker
with additional costs. But at the other extreme, you know, sometimes for like a brownstone, like the classic brownstone roof, sometimes the only way to get material there is for the installers to carry it on their back, up a ladder, through a hatch in the ceiling. And that's obviously that's not as efficient as a crane. A good, a nice in-between would be they have these things called blower trucks. And so basically a big, almost like a dump truck, but full of growing media or let's call it soil for now for the green roof.
00:33:35
Speaker
that pulls up out front of the building and there's a giant hose that can go up like six stories tall and it blows the dirt like a reverse vacuum from the truck up six stories and they just spray it like a garden hose but it's dirt so that's a great way to convey materials up. Anyhow I'm kind of going all over the place here but access and economy of scale as far as the square area of the project can greatly
00:33:58
Speaker
affect the cost per square foot of a green roof. I'd say similarly, there's different types of green roofs, right? I mean, there's very gorgeous, like alarmingly beautiful, English garden, meadow-looking things that you may see. If a five-star hotel is building a rooftop amenity space, they're going to want the highest end landscaping green roof up there possible, and they're going to want it to look that nice and green and well-capped for as many months of the year.
00:34:26
Speaker
before the winter kicks in. Contrast that, so that's going to be very expensive on a per-square-foot basis. You would have top-of-the-line automated irrigation to act as an insurance policy in case there's not enough precipitation. You're going to want to have nice lighting, benches, paver stones, walkways, a wider range of herbaceous and woody species. You're going to want to sink a lot of time and energy and money into the design of that. You're going to want to
00:34:57
Speaker
professionally licensed landscape architect attacking that problem to really make sure that it's looking absolutely banging for as many months of the year contrast that with say a sprawling single-story warehouse in an industrial park who maybe they never plan on going up there they never plan on seeing it they only want it because it's going to protect their roof membrane from UV degradation so they don't need to replace the roof membrane every 20 years instead they replace it
00:35:26
Speaker
every 50 or 60 years, and all that green matter up there, as I mentioned earlier, is going to intercept the sun's energy, the photons, and soak up that otherwise
00:35:38
Speaker
heat energy that's going to hit the roof membrane and bake down. For a lot of these single-story warehouses, their air conditioning bills are absolutely astronomical in the summertime and it's just to keep the plants, sorry, the warehouse plants operating at a comfortable condition either for the goods that are being stored inside or for the workers that are in there. And if you just have a black tar bitumen roof and the sun is baking down on that and you're a single-story building, your AC bills can be
00:36:07
Speaker
astronomical but a thin basic crummy looking you know low hanging fruit bargain basement green roof that's only one or two inches deep and you have sedums which are sort of in the cactus family they're like drought tolerant they're not the best looking but they're the workhorse plant species in green roofs
00:36:27
Speaker
If you just build the most basic green roof possible, and you could do that for, depending on the size of the roof, maybe $15 or $18 per square foot, that's before any tax breaks that are available, you could slash your air conditioning bills in that building by anywhere from 60 to 80%. So that, just from the air conditioning bills alone, you'd pay off that green roof in no time.
00:36:52
Speaker
And then again, you could just frankly let it go to hell if you don't care what it looks like, you know, because it's not an amenity space. You don't really need to spend a lot of money upfront on expensive looking plant species and you don't need to spend a lot of time maintaining it. You can just kind of let nature take it over and let it turn into a real nature roof, so to speak.
Incentives and Efficiency Enhancements
00:37:13
Speaker
Okay, so then the flip side of that surely is the benefits and the
00:37:19
Speaker
return on the investment, not just the outgoings at the front end, but what the owner developer landlord is getting back over the medium to long term.
00:37:28
Speaker
Yeah, from an accounting perspective, building owners see their rooftop as a cost center. No one thinks about their building rooftop making money from them. They just think, oh God, this damn thing is going to leak again. And all they think about is how much money they're going to need to reinvest to put another layer of patchwork and new waterproofing on top. And they don't realize that instead of being a source of headache and stress at a cost center, it can be a revenue generator and a source of joy. You can catch money falling out of the sky.
00:37:58
Speaker
whether that's photons from sunlight, stormwater if you're in DC, it can be like your big piggy bank on top of your roof. Building owners should be thinking of their rooftops as buckets instead of lids because there's money falling out of the sky. You mentioned stormwater there. I wanted to pick up on that topic because it's a big one in terms of sustainability and the environmental impact and there's clearly a lot of potential there. So how do you typically talk about
00:38:26
Speaker
the stormwater angle on a green roof when you are discussing options with a client and what are the overall benefits and opportunities there from your perspective.
00:38:38
Speaker
Right. Okay. So they have a program in Washington DC where they're basically storm water. It's such a major issue in Washington DC that they're basically those buildings who manage more than what building code requires them to in terms of the amount of rainwater that they can hold on the rooftop are awarded credits. And those buildings who cannot manage enough rainwater on their property, on their rooftop are fined exorbitant amounts of money.
00:39:06
Speaker
and then they basically then need to buy their way out of these fines by buying the credits from those people who have them for doing a better than basic building code level of managing stormwater and there's a there's a stormwater credit trading program in Washington DC around this topic and I expect this as because the cities are falling like dominoes here in North America who are mandating
00:39:31
Speaker
green roofs for any number of the reasons I mentioned earlier. And as you're going to see that stormwater becomes a bigger and bigger problem and as fresh quality water and cleaner waterways are becoming more prioritized, you're going to see stormwater credit trading programs like that implemented. And so what's happening is people are then realizing that they are then motivated, especially at the beginning,
00:39:55
Speaker
of design to turn their buildings into backups that can hold as much water up on the rooftop as possible, because the more that they can go above building code, that's just free money for them. They basically get awarded these credits, which have real value. And so green roofs can do that. We have these, or they're called blue roofs, a blue-green roof. You could basically have a system that looks like a milk crate, these plastic cells that can be anywhere from 10 to 60 centimeters deep
00:40:23
Speaker
filling the rooftop and then on top of that you put paver stones so that people can walk around and they just think it's a regular amenity space but really below them could be half a meter of empty void space where rainwater is stored instead of cisterns in the parking lots or underneath the building and they are awarded annually not an insignificant sum of money for doing so. Then the other thing we didn't talk about was
00:40:51
Speaker
green roofs when integrated with solar panels. So we talked a lot about green roofs or solar panels on the rooftop, which makes more sense. Interestingly, solar panels lose operating efficiency when the ambient air around them gets too hot.
00:41:07
Speaker
Plants cool the air around them through evapotranspiration. So when you can install solar panels directly on top of green roofing, the plants cool the air underneath the solar panels and help them to produce more electricity. And solar panels now are just a business case, they're so proven.
00:41:24
Speaker
Even if you can squeak out half a percent improvement in the efficiency of a solar power plant, the CFO of that company loves it. But if you can actually tell them, hey, I'm going to reduce your efficiency loss by six to eight percent, I mean, that's in the summer months. That is a massive amount of money. And so, plus, you then get... So basically, you have all the benefits of the green roof on the system.
00:41:47
Speaker
You have all the benefits, sorry, the greener system, you have all the benefits of the solar system, and you get more electricity from the solar. So solar integrated green roofs are big. And then if you want to combine all of them that, below that, you could have the 40, 50, 60 centimeters of rainwater retention and the blue roof hidden beneath, immediately beneath,
00:42:06
Speaker
that green solar green roof area.
Conclusion and Farewell
00:42:08
Speaker
So there's so much going on in rooftops and so much is going to happen in the next five years that people are going to realize rooftops are a vastly underutilized resource to either make bank or solve climate change issues or improve mental health, you name it. I don't want to list all the benefits again for you. Alan, let's draw a line under there. You've been so generous with your time
00:42:35
Speaker
You are a wealth of knowledge and enthusiasm and positivity on such a wide range of subjects. Really, thanks for that and best of luck for 2022. Everyone check out urbanstrong.com and we'll see you in the next episode.