We thank Target for making this design center possible and making this programming a reality. The next round of Harlem Focus Lectures will start in the fall, so please keep your eyes on our website, cooperhuit.org, for the schedule. Tonight's event with landscape architect Elizabeth Kennedy is being webcast live and will be available on our website. Again, that's cooperhuit.org. John Redick is active in architectural preservation and has written on Harlem's architectural and cultural history. John's love of architecture, African American culture, and history have been conveyed on numerous occasions through tours and articles he's presented for the Studio Museum in Harlem, El Museo del Barrio, the Whitney Museum, the Biography Channel, New York's Historic Districts Council, and many other institutions. Please join me in welcoming John Redick. Well thank you for such a wonderful turnout tonight. This is the fifth in the series of talks we've been doing here. There's going to be five more, like you mentioned, in the fall. And we really wanted to look at Harlem practitioners from Harlem, topics that reflect on Harlem and the environment. So you wouldn't even think of Harlem when you heard the topics. You just thought you came for the topics, but we've always tried to riff off of those topics, relationships that tie back to this community, which I feel is a significant community in the global sense of New York and the Black capital of America in terms of Harlem. And so it's been a really great fun to have people kind of look at us and come to the neighborhood of a different point of view and discover the layer of history and design and invention that's going on in the community. So it's been a pleasure I've known Elizabeth Kennedy who's going to be joining us in a minute. Elizabeth can come on. Elizabeth's a landscape architect. She's been practicing here in New York. She came to New York around the same time I came to New York. We won't say when. And appeared when New York was really evolving. And one of the things that I feel in terms of the evolving and changing in New York is that African-American practitioners came from a lot of different places because we love the mythic Harlem. We love mythic New York. We were also drawn to mythic Harlem. And a lot of the changes that we see when we talk about gentrification or changes in the community really have been generated by African-American practitioners who were doing it when there wasn't really money or interest. We're really innovators in making a lot of this happen. I consider Elizabeth one of those people. So I think you're going to be for a really wonderful evening of landscape design, but thoughtful landscape design that really looks at environment and culture in a very unique way. So I welcome Elizabeth Kennedy. Thank you everyone. Thank you first of all for coming out on an evening that promises that it might rain. Thank you John for thinking of me for this series. I've been really hopeful and impressed that it's happened. Thanks to the Cooper Hewitt for sponsoring this important series. And of course, thank you Target. I'm there and it's nice to thank you for another reason besides shopping for things like two o'clock in the morning. This is going to prove whether or not I can talk in Shugum at the same time. Many of you might have already seen this cover. Some of you might get the New Yorker, but I figured that it was a great way of introducing the topic, not necessarily by talking about what we do specifically, but alluding to a trend that is of growing importance to New York. The title of the presentation today is Up on the Roof and some of you know this as a Drifter's Song. Others of you have no idea who the Drifters are, but for those of you who know that song and for those of you that song, I'm guessing from the age group and the generational spread in the room that it was for us many of our childhoods, it's a great song. It's an urban song. It's a song that was written and it talked about a time when not everybody had air conditioning, when getting up on the roof meant an escape from all kinds of concerns. You went up on the roof to cool out. You went up on the roof to get away from your family. You went up on the roof to get away from your boss, get away from work, get away from care. You went up to read the New Yorker. But the thing is, until recently, you really didn't go up on the roof to grow an acre of vegetables. You definitely didn't do that. And particularly with the irony of the song, of course, is that it was escapist, but I'm here to tell you that roof farming is probably the most labor intensive activity I've ever seen. So we'll talk about that in a bit. I began my firm 18 years ago and when it started, I certainly wasn't thinking about doing roof farms. We were doing residential work for clients with very deep pockets, luckily. And moving on from there to work in the public sector, I see some of our early sponsors in the audience, African Burial Ground, and work here in Harlem at Harlem Stage. I see that the street work has completed, and so they have to restore the landscape there, but we were working there. And we have had an opportunity to be involved in significant historic restoration projects. These are the Hunter Flyer Road Houses in Weeksville. But one of the themes that has sort of repeated itself in the course of my firm's work, and the thread of logic that actually led to our doing the roof farm actually came about by looking at the number of times that water as a topic and water as an issue to be developed, and water as a design tool, really.  And where we really began to look at water in a sort of different way was with the Weeksville Heritage Center, which was the second part of the restoration of the Hunter Flyer Road Houses and providing a museum there. What you can see in these presentation views is the idea of a landscape that puts the Hunter Flyer Road Houses in context. The surrounding neighborhood is very urbanized. It's not the Weeksville houses, I forget now. I'm drawing a blank. It's public housing across the street. And I apologize for not remembering under pressure. But the neighborhood is rapidly changing. But the goal in this project was to, first of all, create an appropriate context and to continue the feeling of openness that persisted on that site. And just a little bit about Weeksville. If you don't know about Weeksville, it's the African-American community, early African-American community in Brooklyn for which these few houses have survived in a context that really much has changed, as Elizabeth was saying. Very much so. And this is generally the presentation site plan that you can see here. And I will, if I can find the pointer, show you a couple of elements. These are the Hunter Flyer Road Houses. Actually, if there are two houses here, there's one here. And there's one here. These are listed on the National Register of Historic Places. And the fifth building is not listed because it's a replica, the original building burned to the ground. There's a new museum under construction. All of these were urban renewal sites that were combined to create what's called the interpretive site here. And in addition, there's a parking area that'll be eventually constructed across the street. And this dashed line that you see is a road that extended from Jamaica Bay all the way up through Brooklyn to what we know as Fulton Street, but used to be known as the Jamaica Turnpike. And this was the famous Hunter Fly Road. And these structures were on the Hunter Fly Road.  And what happened is that when Brooklyn modernized, when it urbanized, its current grid just marched like Sherman across the landscape and obliterated many, many, many of these small communities that had been developed after slavery ended in New York State in 1827. Weeksville was one community that was named for James Weeks. Another such community was Carville. They were relatively close together. But you can see that through serendipity, really, these houses were preserved and then this site has been regenerated around it. Now, what we have here are three wetlands. And that was really the conceptual development and the driver talking about how we used water on this site. The site drains this way. This is the high point. This is the low point. And in order to create these wetlands, we actually graded backwards in order to be able to create relief on the site, actually slow down the passage of water, create absorption areas. And we developed this really on the basis of the analysis diagrams, the relationship of the modern building and those spaces as they projected onto Fly Road, a point of transition right here, which is very close to a property line in the houses. Just to go forward, we built a model in Sketchup. And I'm here to tell anybody who wants to work in my office, you need to know Sketchup because that's all we use. And what we did was create the flat plains around the building, the large agricultural field. We created the swales, creating the wetland areas and the movement of water from this point back to this point. And we're able to make sure that we actually got water to move by creating two berms. And what happens is that when you leave the museum building and you walk across, you walk between a berm here and a berm here. And that's all that indicates that there's the Hunter Fly Road until you get into what's the historic precinct. We used the model to see what we could do in terms of the grading. And we had foreground, mid-ground, and background relationships that were set up because we did the grading this way. And this is an area, obviously an area of construction progress site of the site. But you can see how the elements are coming together. You can see the boardwalk that floats along, but also creates as a hard edge the remnant of the farm grid. We're small. We do a lot of projects at the same time. So what then happened was that we were asked, on the basis of that experience of claiming to create wetlands, to supervise the ecological restoration of Oakland Lake Park. What we did there, Oakland Lake, I'll jump back a couple of this little red dot here. Oakland Lake is a contributing watershed to Alley Pond Park Preserve. Some of you may know it. A significant marine title and upper estuary wetland. The park is known as Oakland Lake Reveen Park for very specific reasons. There are extraordinary ravines all through this topography. And with it came erosion that really diminished the quality of the lake water itself. So we were involved in supervising. This was not our design, but we supervised stream construction and rain garden construction and wetland construction in order to stabilize, mitigate the erosion, stabilize the site, reintroduce certain wildlife habitats. And we were able over time to really also create or make sure that they created safe access to the waterfront. And we've already seen tremendous change there and parks is already moving forward to phase two of the restoration of Oakland Lake. The third project that I want to talk to again about water has to do with a very large green roof that we did for as a sub consultant for the United States Postal Service. This is the Morgan Postal and Delivery Center, which is a block and a half behind and south or west and south of the 34th Street main station. It's where all the mail until very recently was processed. The problem is that there's not that much mail anymore because we electronically send everything. But this was a two acre roof in Manhattan. And you can see the scope of it under construction. This is what we were actually implementing this in November. The idea really the basic program was that we were providing break space, open air break space for employees. And we were looking to do other things like try and mitigate heat island effect and other sort of the broader 50% coverage of green area lead goals. And water retention was not the primary goal of this project, but we did find the course of building it in the dead of November, incidentally, and getting it established and then getting it going that there's almost 100% retention of stormwater on this roof. For those of us who live in apartments and we don't know where exactly what the breakdown of our rent is, we pay the city, we pay the DEP to use the municipal storm sewers. And for a facility like this, which has many roofs, this was just one of I think five or six, the first year resulted in a $30,000 credit on stormwater contributions for this facility. It's more than I make in a year sometimes. So it was quite impressive. We looked into having a photographer who actually came to look at the high line and ended up on the roof and took wonderful photographs. And this is Rick Dark and he's been very generous. Jack Travis will know that when we were working on the Kalahari, we did numerous studies for that central courtyard on the second floor. This one was not built. But again, we're looking here at 50% coverage of the green roof. And if you want to know, that's what 50% looks like and how we could introduce bands of vegetation and for that matter, bands of water that would collect on an ephemeral basis in terms of the design. Those of you who know particularly in green roof residential construction, the roof itself tends to be pitched, but the paver level can be perfectly level because they're elevated. And so that allows you to hide a number of sins. And what we were trying to do was make sure that we could create over these distances adequate depth to get proper growth for vegetation in this matter. This was not the scheme that we went forward with. It was more of a conventional planting. But these were some of the studies that we did. We also work with the Brooklyn Navy Yard who is our landlord. And the Navy Yard is in a very rapid mode of expansion at the moment. There's a lot of change. If you've been there as long as I had over 18 years, it's not the dump as some people said it used to be. So with this has come sort of a development of new sort of landscaped areas, but they're also existing landscape areas that they want to grandfather into new thinking at the Navy Yard. The Navy Yard is very focused on sustainability and sustainable forward development. And we were looking at stormwater retention within some of the marginal areas. That led the Navy Yard to say, okay, you know, I believe I've been approached by the Brooklyn Granges. Is that whom I'm seeing in the back there? Is that Ben? Okay. Can't see that far. But there was an opportunity through DEPs, I'm drawing a blank again. I'm sorry. But Green Infrastructure Program initiatives. And this is very important because there are grants that come up regularly. There is a generous amount of funding for people who want to do innovative projects. I'm not looking to compete with any of you for work, but it would be not good for my karma if I didn't share this information. The recent storm made a real difference in kind of looking at all the stormwater forced the city to release a lot of sewage because it raised the water level. And so the raw sewage had to go into the waterways in ways it wouldn't have if a lot of this runoff water, you think about the volume of water on the highway, those things that are going into the storm sewer at the same time, is raising this level that makes it impossible for the city to process all the water. So this makes a big difference. John is absolutely correct. New York sort of has two approaches to its stormwater management. There are areas of the city that have separate storm and sanitary sewer lines. But there are other areas where the storm and sewer lines are combined. And in these areas where they're combined, when you have sustained what they call rain events, when you have heavy rain that goes on for a while and you have, you know, within a 24-hour period, you have an inch or more, you have problems. And as we know, particularly in the summer, it means that you can't go to the beach, you can't go to the Hudson, you can't do anything really near the water because the system is overwhelmed and the default position is to discharge untreated sewage into New York Harbor. So this is the reality of living amongst 8 million people. We, you know, we do generate waste. And how this could be innovatively managed has been one of the past focuses of the Bloomberg administration. And what's happened is that wiserheads than I have calculated or ascertained that if we, if they trap the first inch of this water, they're good, you know. And so that actually leads to making innovative projects absolutely accessible. It's much easier to capture an inch somewhere than to focus on doing 5 or 10 or tremendous water retention capacity projects. And what's meant, what's happened is that at a very exciting level, at a sort of manageable, a digestible level, let's say, grant seekers have been able to get started on a number of different types of projects. Green roofs are one, stormwater, bioswales are another. They range with all kinds of rain garden applications, things like this, where the actual sort of civil engineering of stormwater detention is being looked at from a quality of life in an aesthetic standpoint. And grants are annual, there's a lot of funding, you know. So the city would be happy to get applications. Based on the fact that we had done the Morgan Roof, which was a 2-acre roof, and the fact that we had done work in the Navy Yard on fire attention, the Navy Yard approached me about advice on an application for a roof that they were going to develop with Brooklyn Grange on building three of the Navy Yard. This is just after it had been improved. And indeed, just to encapsulate, these are the various water pollution control plant, sort of watershed areas of discharge. The Brooklyn Navy Yard is actually treated by the Red Hook Water Treatment Plant, which is a quite small facility. And you can tell that its watershed area is also pretty small. And in fact, the large red rectangle points to the water treatment plant. It was actually built on a decommission part of the Navy Yard itself. And the circle is building three, where the roof farm is. So we're talking about neighbors here. The basis of the application was, as I said, the DEP said store one inch of storm water in an innovative or effective way. And we want to see this. If you can back it up with the numbers, we will fund your project. And so we looked at the entire area of building three green roof, and we have it's 68,000, 4,000 square feet, as you can see, the volume retention of one inch. And in an inch rainstorm, we have to do 5,700 cubic feet or 42,000 gallons of retention. In other words, it's like a foot per acre, you know, a foot of depth per square foot, which is like holding a foot per acre. We had certain challenges. Building three's roof has to be actively maintained by the Navy Yard. We did not have 100% coverage. When you do green roofs for coverage, I mean the the key issue is square footages. It's coverage. If you can cover every inch, the system itself will allow you to retain that inch within the medium, the growing medium, and I'll go into that a little bit more. But when you cannot cover every inch, and we could not cover every inch, and again to show you what percentages and square footages look like, this looks like it's almost 100% or at least 80%, but this is barely 60% coverage. And we were obliged to capture 100% of the water. So this meant having to do watershed studies and other things to make sure that we were able to discharge two areas that are shaded in blue, water that fell on the white roof. This was one of the models that was generated to see what a farm would look like on the roof. Again, that's reflecting the 60% coverage. That's just another view of the same model. And just for a show of hands, how many people are familiar with typical green roof construction?  Okay. I'm here to demystify this. This is not rocket science. The systems are actually very, very, very, very simple. And what I believe is actually somebody probably in Jersey, in Germany, just realized that you can take waterproofing products, stuff that you usually put on the side of a building, a side of a building foundation. And if you lay it flat, you'll have the same properties of protection and retention and all the rest of it. And you can put a mix of porous aggregate and compost on top of it. And voila, there it is. That's a, that's only a very slight simplification. What we have here, and I'm going to start from the bottom.  Here it's called structural support. This is your waterproofing membrane in this system. This is your insulation, which apparently, and I think I believe this is what they call an Irma roof. There are other roof systems where the insulation is below the waterproofing. This is what we call, it's a drainage layer. And if anybody has done building construction and put drainage boards on the side of buildings, you'll see that it's almost the same thing horizontally. So we sometimes call this the egg crate because in certain applications, it actually looks like the, the cardboard thing that you bring eggs home in, only larger. It has a filter fabric, a geotextile above it. This is a mix of usually something like expanded shale and some sort of nutrient layer. It's usually compost nowadays, but it's sometimes it's other things. And there are your plants. No, Elizabeth. Okay, let me come back to your question at the end because it's a critical one because I want to, I want to come back to that question. I mean, in terms of a roof farm, that's one of the dividing line criteria. So here is sort of another version of that, of that roof. And you can see that it's sort of designed that wherever you have water falling outside of what's called the overburden area, this, this water falls on the roof and it's expected to migrate underneath the green roof medium towards a drain. Well, we had a problem where we could not let that happen because as we say, you know, the condition of the grant was 100% retention. And so what we came up with instead, and this was based on a throwaway comment made by the contractor at Morgan, is that we realized that below the growing layer here, if we replaced this with another layer of expanded shale aggregate that was not bolstered with nutrient materials, this also has water retention capabilities. And so what we were able to do is, is filter in water and retain water within this medium while not compromising or sacrificing the ability to drain if we exceeded that one inch. It's like a sponge almost. It's, it's, it is except that it's like hard, right? So it would be almost like absorbing water in very dense coral that could, that could hold water because of its porosity. And what we ended up deciding or figuring out was that the thickness of this layer or the depth of the layer was calculated on the basis of everything that fell in that 40%. Everything that fell on the white roof was calculated as retained in here because we knew that particularly since we had organic material in the growing layer, we could handle 100% of the first inch of whatever fell on this. So we had a two layer system. What's the dimension roughly of? Okay. This, this wonderful drawing, this is about six, a six inch edge. And for this particular product, this is a six by eight inch slotted edge. And we put the eight inches in this dimension and the six inches here. When we got closer to the drains, the relationship changed. But we wanted this, we worked this out on an average depth. Because at the same time, we wanted to keep the roof load relatively light. And we knew that most of the important load would be in the growing layer of this. Now it happens that building three has a loading capacity of 160 pounds per square foot. When people talk, that means that I could jump up and down on that roof, right? A lot of roofs are only designed for snow loads, which are 40 pounds per square foot. So that limits the inventory of roofs that could be developed for farming in this model, in, according to this particular model. That's a development cost. It's, what's happened here is that generally you want to see what, what, what you, I mean, if you have new construction and you're starting from scratch and, and, and you have a developer that's willing to put a heavy roof on a building, then yeah, you could get a 200 pound roof and, you know, knock yourself out. Not every, as you can, you can imagine, the Navy Yard has a lot of industrial buildings, a lot of flat roofs, but not every flat roof in the Navy Yard has capacity for a roof farm, as it turns out. And other, other developers of green roofs have done different things, but donage, which is the way you kind of distribute loads across spans, is expensive. And most in New York, I mean, if you think in Harlem, the wood frame buildings that, you know, brick party wall and it's wood framing, the likelihood of it being able to really carry really heavy loads of soil and planting, it'll be more limited than more contemporary construction, which is probably steel construction or concrete deck, which could take the look more of a load. Once we figured that we had, you know, built a better mousetrap in that sense, that we had sort of been able to retain water that was running beneath the system towards the drain, we then addressed our second concern, which was that the growing medium that is generally sold is absolutely nutrient poor. And I'm going to say this about 80 million times for the rest of the presentation, it's absolutely nutrient poor. So if you're going to find the one thing you want is rich soil, right? And one of the things that happens is that in building, in doing green roof specifications and doing green roofs, there is the issue of combustibility of materials does not go away. So you can't really put materials on the roof that aren't fire rated. And one of the findings that we found, one of the findings was that the growing medium can't have more than 15% organic content because of this issue of combustibility. So the developer, the actual farm operator, which was the Brooklyn Grange, in the course of this question said, well, you know, we're going to have to really amend this in order for us to get this farm going and so forth and so on. And I said, you know what? It would just be my luck to be involved in a project where we were contributing to the same level of eutrophication that happens on a farm outside of Ithaca, New York. So what we aim to do was create a zone between the drain and between an art, sort of artificially, not what, well actually calculated, but let's say an artificially determined edge where any sort of fertilizer or excess nutrient that was dissolved or water borne in here that made its way through here and was making its way through here, which is all highly unlikely, could then be, you know, the load of it could be dropped in a sump that collected an inch or two of water before it actually decanted into the drain. So we created two zones within the Green Roof area and this area, which was actually, it's quite extensive and I'll show you the following slide, is an area where we started to change the pitch of the slope in this zone here. And again, create the sump within this area. So anything flowing along here that made it into this area would then sit for a while before the water decanted into the drain. This is an area that we felt could be planted with crops that could, were more wet tolerant, that could actually withstand standing water and actually probably needed the nutrient boost of the material that was collected there. Now this raised an issue that comes up in this type of roof development because one of the issues in retaining water on a roof is that you don't want to quickly drain water to the system, you want to slowly drain water to the system. And so you're trying to create flat areas and this is a concern where the roofing industry hasn't quite caught up with, let's say, the conceptual needs of the project. And the contractor in this instance had a lot of innovative ideas that from a constructability standpoint were sound, based on his experience in doing this type of thing. And one of them was to create, to flatten the areas by applying spray foam insulation over a slip sheet to create level areas. And what we found was that the roofing manufacturer said it's tapered insulation or it's nothing. And we kept saying all of your concerns can be addressed, we can score this, it's monolithic, we can break it up, it's not sacred, it's spray on insulation. But the truth is, is that there wasn't, well, if I get called court, it's my opinion, that there wasn't a proprietary interest in that application. And so when you do roofs, this is one of the other things, you have to have the agreement of the roofing manufacturer because you want to put up a system that will be acceptable and warranted for a 25 or 30-year period. So we couldn't do certain out-of-the-box things because the manufacturer said no. This is just an example of another green roof project where that whole sump and condition around the drain is being built. You can see the type of edging that went up, you could see the sort of box-outs that we had to do for other tenant issues. You can see that some of the issues that we ran into in terms of just implementation, maintenance, it was very important to make sure that this area remained clean and clear because this is the white roof and we wanted water to flow in at those slots into the under area. And that all of those things needed some tweaking. So you can see immediately as the roof was being installed, the grains was at work getting set up. And you can see that in their first year, a lot of canes to support tomatoes. Typical practice, you have to have a setback from any sort of vertical transition. You know, if I were to talk about lessons learned, it needed to be much wider. Again, you see the operation. Again, this is the establishment of it. And in year one, it was quite impressive. A variety of crops. Did you have to amend the soil in ways of fertilizers? Well, the grains did their own amendments. I mean, there was a standard specification. They worked with a blender who is very motivated to get into rooftop agriculture and came up with blends with them. And they did a sort of experimental sort of allocation, which by one was the standard sort of agricultural bend. And then another one, they incorporated what's called biochar into the blend to see if there was a difference. I was on this picture. I see the scarecrow in the Wizard of Oz. The Emerald City in the back. And we'll get to that too. We'll get to that. But this was them. And there were flowers. And in year two, we kind of noticed that there was a shift in some of the cropping, some of the things that were planted. They've expanded their operations.  The site's generally cleaner, I have to say. So, like I said, very simple system, relatively easy to implement if you have the right conditions. And we'll talk about those. So is there a future in rooftop farming? This is the Grange or flagship operation. This is in Long Island City. You can see that there are some significant differences in the constraints. In that situation, they were able, I think for one thing, they had a higher parapet wall, and they were able to apply medium, growing medium all the way up to the edges. This was unacceptable to the Brooklyn Navy Yard, and there was a lot of discussion about that because the Grange felt very strongly that the more square footage that they had, the more production that they had, the yard is obviously concerned about maintenance and the warranty of the roof. And from our standpoint, it would have been nice to get as much coverage as we can because, you know, our goal was to meet the terms of the grant. Who gets the farm product? Well, the Grange has different distribution systems. They operate a CSA, they have a thing called Farmstead. They also introduced, I think this year, something that we're calling Flowerstead, or they distribute flowers as well. And they do, I think they operate, or they participate in the farmer's market, and they do have clients who buy produce from them. This is the Eagle Street Farm, and this is in Greenpoint. And what I will say is that both operations just have these killer views of Manhattan, you know? So it helps a lot. Now, in considering the expense, the technology, the applicability, the what I call the socially relevant entrepreneurship of this, it's interesting to compare a rooftop operation with other types of operations. And for anybody, is Brooklyn in the house at all? Okay, all right. But I'm guessing that a lot of people have been to Ikea out in Brooklyn. And if you have, across the street, there is the added value Red Hook Community Farm in Brooklyn. They're interesting, and they form an interesting parallel, or means of comparison, because added values farm is built on top of a disused asphalt ball field. So there are some very similar sort of issues and constraints. You're talking about an impermeable substrate, you're talking about drainage, you're talking about manufactured and artificial soils, you're talking about how those soils have to maintain their structure. So there are some parallels, and then there are some logistical differences. This, as you can see here, asphalt. And what they do is they rely on a lot of composting. This is a compost driven activity. They were blitzed by Sandy. I mean, yeah, I mean, it's amazing when you think about what happened there, that there was any farm left to come back to. And they are struggling to come back. And if you go out to Ikea, there's construction on the site that's a little puzzling to me, because it looks like they're implementing raised beds, which means that the sort of charm of the sort of earthiness that they had going on before, and the simplicity of their model is they decided to move on from that, or powers to be have decided that they should move on from that. But they, sorry? Well, interestingly enough, there was a lot of landscape architectural bread and butter and determining the extent to which salt remained in the soil. And we've had a wet spring. And a lot of it has leached out of the top 18 inches, a lot more than we thought. Yes, I'm sorry.  It's called Flushing because it used to flush. The tide would come in and go out. And we had mixed water, you know, brackish waters, all that. And so, I mean, nature has a way of accommodating those sorts of things. You have to monitor it maybe in amended and certain ways, but it doesn't mean you can never grow anything there again. But I will say that the one benefit that we've seen out in Red Hook was that all the things that are sort of in the ground, you can tell immediately that all the evergreens are gone. They immediately browned out. But a lot of the deciduous material was dormant over the winter. And in the meantime, the rain leached all the salt out of the top layer of soil. And it helps that it's sandy out there. Just in comparison, a few blocks away, there is the Red Hook Houses Farm, which is a NYCHA project farm in Brooklyn. Very, very focused on social justice issues. It's about local war habits. It's about food within the community. Red Hook was also damaged, but not as extensively. No, this is more of a conventional but urban farm project. Let me put it that, urban agricultural project. So these are the main sort of considerations that you have in doing a project. First of all, you have to have site selection. You have to have a building that has a square footage that you believe will be adequate for your operational needs because it'll turn out that this is somewhat expensive to install. I'm getting there. Okay. This roof has to be a 200-pound roof. 160 pounds. But it has to be a roof with a strong structural capacity. And where you find that in New York is in larger, older industrial buildings where the original constructions actually stopped at a live load floor, that they anticipated being able to build above it in the future, like a building garage and things like that. So not every industrial building has a roof that will be appropriate for this type of development in this kind of way. We find that the type of membrane is an issue. When we work on projects that have modified bitumen, what we call black roofs, probably incorrectly, but when we have modified bitumen applied roofs, sometimes those roofs are dead flat. The principle is that it's an absolutely horizontal application. When it rains, the water builds up uniformly at a level and then it decants into the drain. And that type of roof, I think, is sort of ideal in some ways for agricultural applications because of the uniformity of the conditions across the roof. The edging is at the same level. The depths are all at the same level. You don't have to make any sort of calculations or adjustments. And you certainly don't have to build those sumps in the same way. What I call white roofs, probably incorrectly, but thermoplastic, olefin membrane, TPO membranes or PVC membrane roofs, they generally have pitch to them. The applications are different. They're designed to shed water.  So all of those things are sort of considerations. Accessibility. You have to be able to get up and down. Building 3's roof is on the 11th floor. The Morgan roof is on a very high 7th floor. The lower the building with the stronger the roof, the better it is because it just, it minimizes the effort in operating a roof like that. Your choice of crops. Now, we learned because of not this project but another project that the soil, I'm going to use soil incorrectly, but the soils that they, that roofing manufacturers sell you as part of this package is more basic than acidic. It's on the alkali side, right? But vegetables like acid, like the acid side. So you can spend a lot of effort trying to change the pH of soil, or you can go with the flow and plant, and plant crops that prefer alkaline soil.  And so you'll find that there were a lot of tomatoes, but tomatoes are a tough green roof crop. All this adds up to considerations about your return on investment. You were talking about some of the, like the Kalahari where it really wasn't about growing crops, but more like sort of passive use. Very passive use, yeah, yeah. There you could just find plant material that was just adaptable to the. You wanted to find, yeah, adaptable to the, that's, it was more ornamental. You want to find stuff that's adaptable to green roof media there. Yeah. This is not my research. These are not my graphics. It's not anything, but through the wonders of the internet, I actually found research that was done by Terraform One about what they're calling building integrated, building integrated agriculture. In other words, what are the most productive built systems that really work for urban agriculture? And you can see that they have several means, several things, several modes of comparison. The best place is that if you go to, if you go to Terraform One dot org, I think it's dot org, they have this chart there in their research. But this example, this, this line column here is your conventional earth farm. Okay. And it's a production requirements. It, the lower the number, the less efficient it is. So the, the earth farm, you can see it's a relatively efficient model according to this integer. The second most effective is a vertical farm. And you know, green walls and vertical farming is also very topical as well. That's the second most. The third is here's your green roof farm. But you notice that it is as efficient as a flower box in a window. Okay. And that's major because in your cost per square foot development, you have half a cent to produce a, a pound of lettuce, right? In a typical farm. You have five cents in a green roof farm. But when you begin to look at the development costs, a green roof is $75 per square foot. That's the initial investment. That's the initial investment. And then the operational costs because the challenges are being, they're also higher. So are there alternatives? Yes. Now you might wonder what this has to do with green roof farming. This is a vernal pool. A lot of us know this if we walk through the woods in the spring. They're full of mosquitoes in the summer. But they also are very important in stormwater management and recharge development.  Well, I know how to do that. And what happens is that in, in addition to the green roof focus that is happening in the city, there's also an interest in developing what the DEP calls blue roofs.  But for the DEP, a blue roof is a roof that is specifically designed to retain one inch of water over a 24 hour period in a storm event. Because again, they're going back to that same criteria of trying to keep the first inch out of the system, right? And these two are examples. This is a mix, what they're calling a mixed roof with a green roof development here and a blue roof there. And this is another type of blue roof. But if you're going to have a standing inch of water, then it, you know, it has been done before. This is growing rice in Southeast Asia. And this is where I think that rooftop, productive rooftop, I wouldn't necessarily call it agriculture in the farm sense, but productive rooftop cropping can definitely be done. And it's containerized. Okay. Okay. Why would you do that? Well, very, very simply, a blue roof will, through the use of a certain type of drain, for instance, retain the first, in other words, rain falls and it builds up to the first inch before it decants. Okay. And then it will decant slowly. And that drain has what's called a wear in it. And it actually has a collar. And you can, you can dial the collar so that you can raise the collar and lower the collar as you need to. And it will pond an inch of water on a roof. Okay. And that's a good thing. So here you have a situation where you have an industry that needs plants that need to be grown specifically sitting in an inch of water. And you have, you have, right. And you have, and then you have a, you have a situation where the city would like to retain an inch of water. Okay. So whether or not it's raining or not, that inch of water is an inch. So you say, all right, put these two together and you see what you come up with. And so these are not necessarily plants that could be grown in an inch of water, but we wanted to show or demonstrate how the sense of agriculture could be continued, even if you moved to something where you were growing, growing different, different materials in pots, right. So from an, from an, getting there in a sec, from an, an economic standpoint, from a community redevelopment standpoint, from an investment standpoint, this is actually a no-brainer. It's absolutely a no-brainer. It is, you know, your bigger issues are your marketing and your access to your clients. To this point, to your point, I mean, if you were looking to say the city wants you to save an inch of water and there's this benefit or credit you're going to get, it doesn't matter what you grow, you're just retaining the inch of water. So say someone in the farmer's market sells, you know, zinnias, you know, every six weeks at a certain height. And if they're sitting an inch of water over six weeks to get to that height, doesn't matter who you get, you say, I have farmland, I have roofland. Do you have a product that needs to sit in an inch of water for a, for a month to get started? And whatever that is, he comes at the end of that period, takes out what's harvest, what's there, and puts in a new. Yes. And, and, and you're putting roofs in, in development. And the key to this is that you don't need the 200 pound roof. You can do this on a 40 pound roof because the load is different. The load is much less, right? And it's seasonal. You're not looking to have this up there in the winter.  And this happens to be kind of topical because we did have a big wave that came through and made the issue of wetland restoration and absorption and resiliency really topic number one in the city. So there are opportunities to change the focus from I would say like a growing medium oriented type of production to a containerized type of production and still have it look great. Walmart. Think of the flats.   What did I say? Our home. Target. Target. Hi. I have a question from the audience. It's all they need is water, right? Right. So it's a cycle. It's a cycle, right? Yeah, we're gonna let Elizabeth, if we could just go through it. Almost done.  Then we'll take questions and we'll get to the talk. Right. Just as a comparative image, it doesn't always have to be things in little pots. It can be flats of material. Again, the issue is the opportunity afforded by needing to have a situation that quite frankly at grade, you know that if we were on the ground and we had an inch of water, we'd have problems. This is on the roof and it's not. Another sort of approach that we were thinking about is using some of the geotextile engineering products to actually again containerize, but in a sort of grander scale. So this is a what's called a geosell or a geosellular webbing product. It's a ribbon that when you expand it, you get these ponycombs. And these you could do in your rows and you could fill them with material over the separation layers on a typical green roof. And you could actually manage the green roof probably much more easily than the typical sort of what I would call like earth facsimile. The other sort of out of the box or parallel thinking way of doing this is to use something that's called compost socks. And compost socks are tubes that are filled with compost and they're used to use significantly in erosion control. And they are more effective than silt fences and they produce again better water quality than all of these things. But they happen to be planted as well. And they're used quite often in strawberry production, but they can also be used to grow a wider range of crops. And you can actually see this, this isn't a rooftop, but this is again the row of the bedding with a compost sock. And these are actually hay bales that they sit on top of. So you don't have to get so low. It could be a little, but it could be the rooftop. This is again my point. So again, this goes back to the original model. But this is just what from an aesthetic standpoint, what's also possible if we expand the idea of roof farming to other sort of modes. We did a lot of cribbing from the internet for this. So it's all here. So it's all credited. And thank you very much for this. Now we'll take a few questions. Do you have to speak into the microphone? Please wait for the mic before you ask your question. Thank you. Do you have a question? Everybody's just going to run up on the roof. Okay. One over here. Oh, great. Here, one second. What's the specific goal of the one inch? Is it to keep a certain amount of water out of when a storm happens to keep it out of the sewage system? The DEP believes that 90% of the storm events that happen in the city are one inch or less. And so their feeling is that if they can capture that first inch, they've addressed most if not all of the storm events for a year. And so that's why there's that one inch sort of goal and cut off. It also means that in terms of detention, an inch of water is actually a lot of water. You know, when we did that slide and we showed how much water in a storm event, you know, it was 42,000 gallons on the roof. That's an extraordinary amount of water that you don't kind of realize because it's, you know, it's running and it's just charging all the time. So that's a reasonable amount of capacity to look to build in terms of innovative systems as opposed to going to sort of the sort of very expensive mega civil projects that would remain underused because we're not, you're not hitting that capacity. Also, you're reducing what I would kind of call rush hour because now in that first, that period where that first one inch is coming, the sea's got to capture all that other water where they're not capturing it. So you're delaying that opportunity of all that water coming at the same time. So that means maybe the system could deal with that first wave a little better because some of it's not going there right at that first minute. You're delaying that volume of water. But also from another standpoint, the beauty of the one inch means that you can be very entrepreneurial in the development of systems of capture. A lot of you have seen the bioswales that they're building at bump outs and corners. That's part of the effort. It means that there are several not-for-profits that are looking to address some of their open space issues through retention. It reduces their operational costs. It also gives them the benefit of the city and the city is paying for the installation. So it's a nice thing. There's a question for you. Just one second. Somebody have their hand up. Absolutely. Thank you. I'm from Brazil and in Sao Paulo, we have a lot of problems with rainwater and the city can't control it. They have no idea what to do. It's really been awful. So how you plan to expand these amazing things that you show here to another country? For example, if somebody in Sao Paulo in Brazil would like to know more about it, how they can do what you were doing here because it's really amazing. Well, thank you. Let's go to Brazil. We're going to go to Brazil. If you believe in the six degrees of separation and the connection, I mean, what happens is that people like yourself come to events like this and the word gets spread. It also helps if we could actually get our website organized and things like that in a way that actually showcases what we really can do. But it's far like this where you talk more. It's advocating on behalf of some of your clients who are doing this type of work. It's making sure that, among other things, you get credited because a lot of times what happens is that you'll do a project and if you're not smart about it, it becomes a thing in and of itself and it doesn't grow its own legs. So all of those things are what adults have to do in order to share. Part of this is looping into when you have developing countries and you have rapidly growing and rapidly modern. I mean, Brazil is a sort of miracle country right now. The technology allows us to communicate a lot. It would be in my interest since I'm hearing this. I'm sure that there are people in São Paulo who are very much aware of this and are trying to organize around the same issue. The thing to do is to make the alliances, to be a resource to those people and then you begin to share. So have no hesitation whatsoever to drop my name. I really appreciate it. Just wait for the microphone. As for contact information, if there is some follow-up, that's not inappropriate to discuss what I want to talk about here. This is not typical for me, but we do have business cards here today. So I'm going to make sure that you get a card and it's very easy to look up Ikele Studio on the web. Sorry. I might have missed this, but I was hoping that you would talk a little bit about Palahari since it is a Harlem project done by developers that are based in Harlem that started their whole business on sustainable development and that they did of a project that would have a green roof and we worked on that as well. But we had an image, she's looking to see if we can find it. We did talk about it a little bit earlier. Just revisiting my entire portfolio here. No, we did sail very past it. Where did we go? Yeah, no, no, we did show it. Okay, we did talk about the Palahari. Talked about the Palahari very briefly and we can talk about the Palahari for a number of reasons. The developer was not interested in stormwater detention. The space was a common space. They wanted a decorative space. In the course of developing the project, the decision to cover at least meet the 50% coverage requirement for lead went out the window. There was no interest in that anymore. We redesigned that space umpteen times. I think in all fairness to everybody who was involved and Jack was involved, we came up with something that we finally all agreed on. I think when it was built, it came out really well. It is not properly maintained and it's not the fault of the staff there. There were some other decisions that were made that worked against it. But that project was like how long ago Jack? Eight years? Seven or eight years ago. In the seven or eight years, Green Roof technology has completely changed. Not just incrementally changed, completely changed about two or three times. Even if we were to revisit that project, we would probably go about it a different way. We'd probably have different conversations with the client. It has a large center area, but a large part of that is in shade. It's not brightly exposed. It's not full sun. What happens is that Green Roof is more successful when the exposure is full sun. That again has to go back to the growing medium. So there are a lot of challenges there. I do think that that project was very ambitious. There were a lot of things on the table, but this is one of the conflicts of working with developers with whom you don't workshop. I think if I were to do that project, again, I would sit down with people and bring them up to speed on what was possible in terms of Green Roof design and then start to talk about the design itself. Yes. First of all, it's Karen Phillips. We should all know that. She just hates it. But I'd just like to make a couple of comments because everything that Elizabeth said is absolutely correct. But what I think the audience should know is that Carlton Brown, who was one of the partners in Full Spectrum, which is I think the largest developer in the Harlem community, is an expert on green technology and sustainability and building buildings and getting the LEED certified level accreditation that's necessary. The problem was finance, as you all might guess. And I think the reason that we went through so many iterations is because one, we tried to do one of the most innovative green roofs that we possibly could that could be connected with a very strong black cultural aesthetic to it. And those two things take a lot of understanding and explanation and iterations in order to go through. I think the reason that we finally resulted in what we did was basically the fact that you had not one developer on a project, but two in a community of means and lack of resources. And at the end of the day, it was the resources that didn't allow her to do the kind of things that she wanted to do. But if you look at the Kalahari, you can understand how the cultural content is very, very strong. But also if you look into the details, you'll see just how the sustainable LEED issues are very strong as well. And it is a project for the community with a black developer, a black architect on board, a model to think about, but it's the resources, almost always that the hampers are community like this. And that's what you got here as a result. There's two questions over here. We'll take two more and then we'll repeat. Short answer is yes. Well, what happens is that when you have an experimental technology, it gets installed in two, it's tested. It gets installed in two or three medium use locations where if it fails, it can be removed and replaced without just too much disruption. So permeable concrete, which is not part of this discussion, but is a sustainable issue, is very attractive. In my opinion, when you're still in a freeze-thaw zone like New York is, it's more difficult than using it even as near as Philadelphia, that there's almost five to 10 degrees difference sometimes in the winters there. And so definitely won't work for upstate New York, definitely won't. It's difficult here until they get sort of the aggregate approach to where you have the drainage. It happens, permeable pavements tend to be spectacularly expensive because the actual, the substrate layer, the drainage layer, is two feet deep. So whereas if you're ordinarily building a sidewalk, you can get away with eight or nine inches over five years. When you're doing, when you're doing a permeable pavement, your excavation is between two feet and 30 inches. That alone is a huge expense, right? So that's where permeable paving is. And also in this period where you're seeing a lot of interest in this sort of thing, you want where the money is coming in to really have an experiment with as many different things now, as opposed to having a one answer solution, because that one answer solution fails after, you know, New Orleans sees that New York got all this money or some other place and sees that, okay, you got a billion dollars, you spent all this material, and five years later you're ripping it out because it didn't work. You're much better off with smaller scale projects that are really sort of venturing out into what options are and testing the waters in a bigger way. Let me take one more question. You've had your hand up for a while. Okay, quick, quick, quick. Green, in terms of all of the construction sort of industry costs, landscape improvements tend to be the least expensive, right? And even when you get a job with a high level of finish, it tends to be the least expensive. There are very few shortcuts that you can take on green roofs. It's like doing conventional construction. And the payoff, the return is mixed. You're not working with soil. You're not, I don't want to get too technical, but the benefit, in my opinion, is the jury is out still on the sustained benefit. And it's partly because of the conceptual idea that you're doing on a roof what you can do on the ground, aesthetically, you know, so there's that trade off. It's also an expensive way of doing, of affording the other benefits. Like if you're doing it for stormwater retention, you can also do the same thing by building simply a blue roof, it turns out, right? Fraction of the cost. You can, it does, most green roofs don't build biomass. So the idea that, you know, the notion that's tossed out that we're reducing heat out of effect and sequestering carbon, it's not happening on a green roof. I'm sorry, folks, right? So there are all of these other things. Now, are they worthwhile projects? Yes. Are they worth exploring? Yes. Are they a benefit to the city? Yes. But we're at the tip of this particular iceberg. And in 10 years' time, we're going to be talking about this in a whole different way, and probably redoing 80% of the projects that were done before. My advice to anybody who's interested in this technology, if you get the soil thing down, you will have won a lot of. Yes. You can see in this New Yorker cover, there's a new facet. I mean, we think about the song up on the roof. You know, you just went up on the roof like in the West Side Story movie, maybe you danced on the roof or your mother hung the clothes on the roof. But the physical engagement of the roof as an element to really do things with is very different from this conception. And it really is wiping out that old image of seeing just this black tar roof to something that could be more attractive and sustainable. And I think once that's captured the public's imagination, there's going to be this desire and upscale buildings and all that to have some aspect of bringing greenery to the roof. So I feel the momentum's there, how it gets played out. It's going to be a lot of different things. It's the next question. I do want to hear your question. This will be the last. Well, what you're really talking about is the loads on the roof. So the industrial buildings, for the most part, just built to handle loads. Maybe, you know, vehicles went up on the roof or where there's a kind of level of load that's not typical that you see in other buildings. But you can still, in New York, maybe not doing the whole roof of a brownstone building, but it could accommodate brown fields. Brown fields. Well, a brown, I don't understand. I kind of understand where the question is going, but I really don't understand the question. Could you clarify it? You're qualifying a brown field, including the structure? Well, I mean, if you look at the dump, the city dump right now, they're planting plants on it that's amending the quality of that soil over time that's going to make it available as a park. So plants have this ability, depending on what the brown field condition is, to help amend what that problem is. I don't know that we're doing for every... Let me answer the question in terms of this presentation a different way. When we were talking about the Red Hook farm, the Nitra project, not the... Okay. You raised planting beds to get above contaminated soil. And a brown field, you're talking about contaminated soil, right? So whether or not, they've been repurposing brown fields for years. Brown fields are... It's a very hot topic also. Redevelopment of brown fields is a very varied and multi-dimensional consideration. Again, if you want to compare doing a brown field to doing something like a green roof, whether or not it compares favorably in terms of the development cost of doing that versus more readily accessible agricultural land is a question. Okay. So it might be as expensive. Logistically, it might be a little easier to manage because it's that great as opposed to in the sky. But there are other costs in terms of food production that might not work. Now, if you want to go into nursery stock production, it might work very well because the return on that kind of investment is different. Okay. Well, thank you. Thank you, everybody.