Green Roofs & Nature-based Solutions

Shane Clarke: Kia ora, tēnā tātou katoa. My name's Shane Clarke. I'm the general manager here at Nuralite, New Zealand's leader in waterproofing. Welcome to webinar 40. Today's particular topic is about green roofs, or more specifically, we're going to discuss the functions of a green roof that make them the perfect choice for our future urban development. This topic is important to you because as our environment changes, our populations increase, and our urban areas become more densely populated, the functions of a green roof are going to be more important than ever for our future urban development. Now we've got a bit of a change from our schedule program. We were going to have Zoe Avery, the Associate Director of Design at the University of Auckland, but she's been unable to make it today. So instead we have John Simmons. Director of Nuralite and also a member of the Design for Nature Committee, which has been responsible for bringing the World Green Infrastructure Congress to Auckland. So this promises to move Aotearoa forward in adopting nature based solutions to our challenges, but we'll talk about more of that later. We also have Will Thorne, Director at Greenroofs Ltd. Will and his wife Claire first became aware of Greenroofs after a holiday in England and thought, why can't that work in New Zealand? So they established Greenroofs New Zealand in 2005. And since then, they've supplied and installed over 5, 000 square meters of green roofs throughout New Zealand, from the Bay of Islands to Dunedin, all the way down to Queenstown. Also joined by Dr. Benedict Pacquiao, Nuralite Architectural Advisor, who's been involved in the construction sector both here and overseas for about 15 years. Benny has a PhD in chemistry and has 15 patents for organic winders. used for glass and rockwool insulation. She also has a patent for malaria medications. Welcome, Benny. Thank you, Shane. These achievements didn't come without any hiccups. Here's a fun fact. Benny once accidentally sent fire to an insulation manufacturing plant in Belgium. Progress over perfection, Benny. I love it. So yeah, it looks like we're in some great company today and we're stoked to have been working with these people for at least the last 15 years. So today's webinar is set for around 30 minutes. Towards the end we'll have time for a Q&A. So during the webinar, please feel free to pop your questions in the Q&A section below. If we don't get to all of your questions, please don't worry. All the registered attendees today will be sent a recording plus a copy of the Q& A session. CBD points. Yep. We've got those as well. so just like all our previous webinars, which can be seen on our education page, each half hour section is accredited for five NZIA CBD points. So at the completion of this webinar, there will be an automatic survey that gets sent out. So anyone who wants to can fill in the form and get their CBD points. So I guess if there's one key message we'd like you to take away today is that green roofs will help enhance our future urban development. So although this is a webinar platform, we do try and make it as interactive as possible. So along with the Q&A function I mentioned earlier, we're also going to run a few polls along the way. This helps us establish who's in the audience and how best to pitch our message. So we're going to kick off with one of those polls first. It's just this nice simple one. Have you ever been involved in a green roof project before? Alright, we'll see what pops up there. A few veterans, few newbies. This is good. Alright, cool, thanks for that. So welcome John. Thanks very much for standing in for Zoe today. Some big shoes to fill. John Simmons: Yeah, thanks. Thanks, Shane. yeah, no, I'm a very poor substitute, but I'll do my best. This is actually a subject I'm really passionate about, so I'm actually delighted to have this opportunity. I'm very interested by that survey result because to see, 36 percent of people have been involved with the Green Roof Project in the past, shows there's a level of interest that's really good. And we're definitely seeing that interest picking up within our business. If we just jump to the first slide, just crack into it, eh? Look, obviously, climate change is a thing. No one can deny it now. we've just seen some slides here around, the flood event that happened in Auckland in January last year, I remember fondly because it was the day we moved house and, it was, it was traumatic. we've obviously got flooding events happening, but we've also seen, temperatures going through, through the roof particularly in urban environments, that's called the urban heat island effect, which is because of all the asphalt and concrete that we're building with is trapping the heat and then reflecting it back. so it's actually a, just a spiral of effects that are happening. In today's talk we're just going to focus on those two impacts. There's obviously a multitude of other impacts, but we're just going to be talking about those two today. There's a term that's called nature based solutions. And, it's actually one of the five, nature based solutions. Pillars that the government are using to help address or mitigate the impacts of climate change. They have one called nature based solutions. partly it's around planting more trees to absorb carbon, but there is a lot of other opportunities to use nature based solutions to mitigate or address some of the impacts of climate change. You can see on the slide here, we're talking about, for example, rainwater harvesting or subsurface detention systems. Swales are all part of nature based solutions. But for us, we're focusing as much up on the roof space because we're Nuralite the flat roof experts. And so we're talking about living roofs. Blue roofs, which are roofs where water is actually accumulated on the roof rather than actually going straight to the stormwater system. We're also looking at how the roof space can be used to mitigate the urban heat island effect. And ultimately it's actually about creating an urban environment that's more pleasant to live in. So you're actually saying we're going to have a denser urban environment, we actually have to make it more pleasant, and more nature around it so that we're actually more, more used to what we want to live in. Then we jump on to the next slide. When we're looking at a green roof. specifically, and these are, we're talking about urban green roofs, rather than necessarily, aesthetic green roof. We're talking about green roofs that are in the urban environment. You can see that some of the benefits, related to water, a green roof will absorb 70 percent of the, rain that hits it, and then it will evaporate into the, environment. So that, of course, stops that flash of water that's coming. hits the stormwater system, that will reduce water pollution as well. On the other side, you've got, the green roofs are actually cooler roofs than a normal roof. either a metal roof or a membrane roof get quite hot during the heat days, especially a black one. A green roof is cooler, helps mitigate urban heat on effect, but also improves the performance of solar panels. So if you're going for solar panels, You actually want to have a cool roof around the solar panels. There are benefits around insulating the building. There's also biodiversity benefits. But the last one there, being is one that I actually want to pick on in this slide. It's actually a better environment to be living in. And it's actually about creating your roof into an urban space that you can live in and you can enjoy. It's not just having a roof that's, Keeping rain off, keeping your building dry, it's creating into another space. we jump to the next slide. Sorry about the quality of this slide, but I took this yesterday at the Green Property Summit in Auckland. And this is, I'm going to do a very poor job of discussing this slide, but this is the Green Star have announced their new pillars for creating a green star balloon. when you look at them around, resilience as a subject, nature as a subject, responsible, healthy. people and places. These are all ticking the same boxes that I had on the other slide. So, a green roof can help you create a green star building. You can use these to feed through into your green star, rating tool. what's the next slide? Can I just talk? Sorry about this way of winging it. But anyway, if I had gone to Berlin last year with Zoe, which I didn't get invited, this is the tour that I would have gone on. And this is why I love these photos because they are a real eye-opener. Opening up the possibility of what a green roof or urban environment should be. A really important fact is New Zealand kind of kids itself that we're clean and green. The stats are that we have about 10 percent tree coverage within the Auckland urban environment. In Berlin, it's more like 30%, so three times the trees within the living environment. And you can actually feel it, you can see it in these photos, that it's a much more pleasant place to live, to be frank. This has actually created a playground area on the roof space. And you can see, as I say, it's about turning your top floor of your building into something that's liveable. And we've got some examples in New Zealand where we've done it with our products but I just think these are excellent if we jump on to the next one. So people are actually being invited up onto the roof, and that looks like a fun place to take a kid to play. It's exciting, dynamic, and creating some energy within the urban environment. Jump on to the next slide. Again, this is, just emphasizing they don't have to be a barren space. It's not just a plant in a pot, it's actually creating a pleasant environment. And it's going to be a cooler environment. It's going to have shade, so you can escape the concrete jungle and get into a much more attractive environment. The next slide. This is a slightly, it's obviously a different type of green roof. this is more, I guess, what we'd expect to see in New Zealand at this stage. But what's interesting about this is that it's a dynamic one. It's got the solar panels. They're actually just freestanding sitting on top of the soil. And they're going to be performing, that's something they perform about 10 per cent more energy efficient because they run cooler. As well, on top of that roof, they've put beehives and they've put just blocks of wood for biodiversity purposes. Again, here are some examples. the one down the bottom left-hand corner, I think, is a really good example of just how you can create a dynamic environment. On a space that could have just been barren, right? And so it's somewhere that's going to be attractive, and you want to hit to, and you want to sit, and you want to congregate. Going back to those building councils, we're talking about people and place. so you're actually creating a dynamic environment. That people want to congregate, so these will all help create a more attractive building. Shane Clarke: you mentioned earlier John, that you went to Berlin, some time ago, before this, and it's obviously changed since then. John Simmons: Yeah, my memories of Berlin, which I mean, Was, back in the 90s, was, as a backpacker, was, it was quite a grey, dull, barren place, actually. and, yeah, not terribly inspiring when I was there. But, yeah, from these photos, it's an attractive place. I actually want to go there and have a look myself. I know even, my experience of going to Paris, that transforming the urban environment there, making it much more human scale, but much more livable. yeah, so I guess the take out message, and one actually I got quite inspired by yesterday at the Green Property Summit, is, a green building actually enhances the value of the building, the stats presented at summit was up to about 10 percent just from the ratings, and it's actually been driven by tenant demand. So you particularly if you want a premium building that wanting to. It's got to be a green star building, it's got to be an efficient building, but it's also even driven by financiers. So they want to, they don't want to be funding buildings that are going to become barren or have lack of demand. So you're actually getting this kind of virtuous circle where it's all starting to close together. And as I say, hopefully driven by some government and energy. I don't expect them to put any money in at this stage, but let's not go there. OK, that's probably my slides. Shane Clarke: Yeah, cool. Thanks for that, John. So John's discussed the why, obviously, why we do the Greenroof and we're just going to go back to Benny from Nuralite. Who's going to talk about the how, And you're going to go through our typical Greenroof system. And the layers and what they do. Benedicte Pacorel: Thank you, Shane. So looking at this green roof buildup, you can see that the construction of the green roof starts with the substrates. It can be concrete, cross-laminated timber, metal tray or plywood. This substrate must be approved by the structural engineer so that it can support the weight of the green roof buildup. On top of this, you can see the vapour barrier. It is used to protect the insulation from rising moisture of the living space below. This way, the insulation retains its R value performance long term. You then have the insulation walls. At Nuralite, we promote the warm roof concept or isolation because our preferred system is the one that provides insulation. Outside the structure and on top of the installation is the roof membrane, which is here 3PG is a double layer bituminous membrane system base layer here is 3PBS a, which is effectively the same one that we use for our Nuraply 3PM, then the top layer is Nuraply 3PG, which is specifically designed for green roof applications, and it contains a roof, a root inhibitor, so that the plant roots cannot damage the membrane, and in turn cannot enter roof or the accommodation underneath. And above the membrane, then is the Nuramat Green Drain is specific to green roofs. It allows water to flow away from the soil, and it runs freely across the surface of the roofing membrane without lingering into green roof buildup. It prevents stagnant water. It also has little cups in it that act as water reservoirs to intentionally retain water, which will irrigate the living roof. And the last part is the exciting part, the selected green roof. It can be pebbles, grass, vegetables, or plants. At times, our customers like to start simply with pebbles, and then they can upgrade later on to a living roof. At this point, we are privileged to hand over to our green roof specialist here, Will, who can talk to us about consideration for a living green roof. Will Thorne: G'day, thanks Benny. Shane Clarke: Excellent, thanks for that Benny. so sorry, just before you jump in there, mate, we've got another one of these polls, and it's funny because it's actually come through in the Q&A about the challenges around green roofs, so it's actually on our next poll. So as a specified designer, what are the things that you consider when you want to, specify or you're thinking of a green roof? I'll just pop you, let that sit there for a couple of seconds. There we go. Yeah, interesting. Cool. Yeah, so like I said, all the attendees will get a copy of all those polls and that today to see. We're all singing from the same song sheet. Welcome to our little soiree. Thanks for coming along. And Benny said, we're very privileged to be able to hand over the green part of the green roof when it comes to green roofs, because we're all good up to the membrane, but it's really nice to be able to hand it over to the experts. Over to you, mate. Do you want to talk to us about some different types of greeners? Will Thorne: Great stuff. Okay, thanks Shane. If we could just go back quickly to the previous slide, sorry, with the green roof buildup. So here we have on top of the Nuramat , we put our, we don't like to call it substrate or soil, we prefer to call it growing medium. So that goes on, and the depth of that is dictated by what type of green roof we're going to use, and obviously on top of that we have our different types of planting. So if we can go forward to extensive green roofs, generally these are the cheapest and lightest type of green roof. the growing medium depth is limited to 75 millimeters. This has a maximum saturated weight of 90 to 95 kilograms a meter squared. So, at this depth, the planting is generally limited to a mixture of non-native sedums and succulent plants. moving on to semi-extensive or semi-intensive green roofs. Generally, this has a depth of 150 millimetres in the growing medium, which has a saturated weight of about 180 kgs per square meter. At this depth, we can start to use some native plants, including, grasses, tussocks, ground covers, things like that. Next we have intensive green roofs. So these have a growing medium depth of usually at least 300 millimeters. so it's more accurately called a green roof garden or a roof garden. and it can also apply to grasses and lawns on top of roofs as well. Moving on to brown roofs. This is where the growing medium is left to self-vegetate from birds and wind-blown seed dispersal. Brown roofs are the best way of replicating exactly what is found at ground level, and over time similar plants, native plants will colonize the area. Spontaneous green roofs, can appear over time, allowing native plants to grow and establish themselves naturally. So it can be a very cost-effective approach while obviously taking a lot longer but still providing all the benefits of a more conventional green roof. next we move on to blue/green roofs, sometimes called blue roofs or purple roofs. These are growing in popularity overseas, especially where there is. It's more of an emphasis on restricting the stormwater runoff. So, as well as using vegetation, blue-green roofs will use other methods as well to restrict the water runoff. So that can include some sort of valve, which can be open and closed when appropriate, wears, storage tanks, things like that. Shane Clarke: Just picking up on one of the questions out of the Q& A, Will, can you mix and match your green roof type? Will Thorne: Yes, very much. Obviously one of the biggest restraints, for us is what weight can the roof take? So if we can, depending on the soil depths, we can calculate and provide maximum saturated weights for different depths. And if it's structural engineer can say that's okay, then we're good to go. So we can have extensive, intensive blue-green roofs, all different sorts, on the same building. Shane Clarke: So just talking about weights there, could you give us a typical weight per square meter for a, I don't know, if you were to grow grasses and tussocks and things like that, what would your typical saturated weight there be just as a rough example? Will Thorne: Yeah. So if that's a semi-extensive roof, we've got a depth of medium depth of 150 millimetres. That typically has a maximum saturated weight of 180 kgs per square meter. Shane Clarke: Excellent. Tell us about this little thing that you do. Okay. Will Thorne: So we are the New Zealand agents for a Dutch company called Sempergreen. So we pre grow their, Seedum Click and Go trays. We've got a nursery in the Waikato and, and currently we're putting a lot on bus shelters around Auckland. So you might well keep an eye out for these and see some as you go around. These have got an advantage of giving a, an instant green roof. We can just lift them straight onto the roof. And, if you ever needed to access the waterproof membrane below, then it's easy just to take a couple of trays out of the way and get down to where you need to. Shane Clarke: A little bit of a case study here. Will Thorne: Yep. So this is, we always like to ask the question, what is the purpose of the green roof? So usually it's a combination of aesthetics, stormwater runoff, bird and insect habitats, all the other things we've covered. In this case, there was a new primary school. The Remarkables Primary School was built in 2011, very close to Queenstown Airport. So one of the main considerations was the green roof and the ballast roof was to provide excellent noise control, noise insulation, sorry, from jet aircraft coming into land or taking off. And then we have another case study of on Waiheke Island. So this comprised two buildings. This is the boat shed, believe it or not, and the next slide shows the main house a little bit further up the hill. we were first approached by the architect for this project when it was at the design stage. there was a preference for a semi-extensive green roof using local native plants. However, the roof was quite a lightweight roof. we were told the weight couldn't exceed 130 kilograms per square meter so that dictated that the growing medium couldn't be more than 100 millimetres in depth. We did, however, know that there would be a bore and a pump on site, so having unlimited water for irrigation allowed us to make some compromises with the planting, so we ended up with a mixture of natives and sedums, and we've also found from experience that we don't like to install green roots in the summer months, sort of December, January, February. As even with lots of watering plants can, they're really exposed and they can struggle to get established. But, in this case, it was 2022, Auckland was in its third lockdown, and we couldn't get access on to the roof until the week before Christmas. The aluminium edging was too hot to handle sometimes, and once planted, we were irrigating six times a day. I think on the next slide, you can see the irrigation going hard out. So it all worked out quite well in the end and also on the next one. Considerations and challenges. In order to guarantee the performance of the green roof, we need to be the last tradespeople on the roof. this was a job, the picture on the left, this was a job in Wellington that we did, we did our planting and everything. And then a few days later, we came back, and there were guys walking all over it to finish off the flashing. Maintenance is always a big consideration. All green roofs have ongoing maintenance requirements. So we need to think about safely accessing the roof and working on the roof after completion, after the scaffolding has been taken down and any safety barriers. So often on a commercial building, this will usually require a fall arrest system. And the final consideration We always like to be able to guarantee the green roofs performance, so we always install a simple automatic irrigation system. a water supply at roof level is really important for us. Shane Clarke: Yeah, that's a complete one-stop shop for the green section, right? You're growing medium right through your plant selection to your irrigation and maintenance. Will Thorne: That's right, we, yeah, once the applicator has done their thing and the roof has been flood tested and signed off, we like to come along after that and do everything else. Shane Clarke: Yeah, no, that's great. It's answered a few questions that have come through the Q&A. There's been a lot around maintenance and irrigation and things like that, so obviously, very important and great to see that you're a complete one-stop shop and offer the whole solution, so it's great. We're on to the next bit, so one of the other reasons John got to fill in for Zoë is he's also a member of this group, which is bringing the World Green Infrastructure Congress to New Zealand. I'm going to throw John a dummy pass again to talk about briefly what it's all about. We've got a slide there John. John Simmons: Yeah, look, last year, Zoe and, John had this great, not this John, another John, had a great idea that they, approach the World Green Infrastructure Conference and encourage them to move it down to the Southern Hemisphere for a change that's, yeah, there's always been a Northern Hemisphere focused thing. New Zealand entered a project if we go to the next stage, which is the Hundertasser building. I love this building. If you haven't been to Whangarei or if you go to Whangarei, you must go and have a look at it. Go look at the art and explore the green roof. As you can see on that one, there are significant plants on growing on that roof that are all locally sourced. As part of it, that building was entered into the competition and it won as the green roof of the year last year, which is quite extraordinary. And, it was agreed that they would bring the Congress down to New Zealand. I'm super excited about the Congress. It's going to be in two week’s time. the speakers that have been, Brought together are just quite exceptional. We've got people coming from overseas who are leading in the area of nature-based solutions and green roofs, and we've also got thought leaders in New Zealand speaking there. We've got lots of local case studies happening. so that we can actually, network and actually hopefully get, some supercharge, some real cool initiatives. The Design for Nature group, which I'm one of the committee members of, feature, Local government people, industry people, and academic people, all with a goal of aligning and encouraging the uptake of nature-based solutions in New Zealand so we have a more dynamic urban environment. so yeah, I encourage everyone, I can see we've got a lot of participants today. Get online and, come along over the next, those two, two days or three days, actually. Shane Clarke: Yeah. Yeah. Yeah. as Nuralite are sponsors of the Greenfield Infrastructure Congress, we're stoked to have negotiated a great deal for all the webinar attendees today. We're about to chuck a link in the chat section, and for a limited time, you can access a limited number of two-day and single-day registrations at around a 40 per cent discounted rate. If you use this link that we chucked in the chat there, the link expires on Monday the 19th. Nuralite will be there along with our friends at Greenroof New Zealand. A bit of a display showing you the how and the why again. I've tried to answer as many of the Q& A's as I can throughout the prezo. We won't get a chance to get them all, but like I say, we'll run through and get the transcript out to everybody and answer that. So just before we leave, there's one more poll. Are you currently working on a greenroof project and need a follow-up? We'd like a follow up from someone from the team. Highly up to you. Run for a second. We won't show that poll result. Excellent. Alright, yeah, that links are now in the chat. I saw it there myself, so it'd be great to see you all there. Thanks very much for our panel members today. Thanks for filling in, John, at short notice. Thanks to the audience for attending. So today's topic was about green roofs, more specifically that the function of a green roof, what it does, and why it's the perfect choice for our urban development. We talked about the different types of green roofs, and we briefly covered a typical cross-section or build-up of the Nuralite green roof build-up and yeah, I hope to see you at the World Green Infrastructure Congress in September. Until then, mā te wā. Will Thorne: Thanks very much. Shane Clarke: Thanks guys.