Ep 114 - Council on Tall Buildings

25 min 09 sec

In this episode of Timber Talks, Antony Wood, President of the Council on Tall Buildings and Urban Habitat, shares his insights on using mass timber in tall building construction for sustainability and efficiency. We discuss the potential for embodied carbon reduction and the benefits of sustainably managed forests. Antony also describes innovative mass timber buildings and the possibility of off-site manufacturing. We explore the future of timber construction and emerging technologies for tall building design. Tune in for this informative discussion with one of the industry's leading experts! 

Timber Talks Series 6

Series six of WoodSolutions Timber Talks, provides the latest informative and entertaining information about the best design practices, latest innovations and interesting case studies and interviews with world leading experts in timber design, specification and construction.

Episode transcript

Adam Jones (00:08): 

Well thanks so much for coming on the podcast. Antony, can you start by telling us a little bit about yourself and what you do? 

Antony Wood (00:15): 

Cause I'm so interesting. Okay. Adam, I will start with, my name is Antony Wood. I am an architect. I am a professor of architecture and I lead an organization called the Council on Tall Buildings and Urban Habitat, which is the Worldwide Trade Association, if you like, for all those who are involved in tall buildings, but increasingly urban density and future cities around the world. 

Adam Jones (00:44): 

Yeah, fantastic. And we're going to get into tall buildings and where it meets sustainability. So my first question is, can we achieve the targets, the embodied carbon reduction targets that a lot of firms are beginning to set with tall buildings? Can it be done? Is it possible? 

Antony Wood (01:02): 

Well, it depends what those targets are, my friend. And they differ from city to city and country to country. But here's, okay, here's my honest answer on that. There's, to be frank, there's a lot of bullsh*t in the industry and a tall building in itself is going to take more energy to operate and more energy in the embodied materials, more embodied energy in the materials than an equivalent number of small buildings because those materials need to perform at height to a far greater degree, environmentally wind, other factors than small buildings. So we need to be clear about this. Tall buildings in themselves are single objects are not necessarily going to save the planet in terms of their energy profile. But where they really, really come into the fore, it's about the benefits of density of urban density. So if you look at the single building in itself, we've got to do the best we can in both operating and embodied energy terms. But the real benefits are in concentrated land use, concentrated infrastructure, and basically the creation of the vertical city over the horizontal city, which is completely unsustainable. 

Adam Jones (02:34): 

Fantastic. There's a lot in that. What is the role of mass timber sort of shoehorning that into this conversation and how can that help achieve some sort of embodied carbon reductions, let alone I think we're, when we're talking really tall buildings, we're probably not going to have a fully full mass sim building potentially at that a hundred story range, which we see with concrete and steel buildings. 

Antony Wood (02:57): 

Well, why not? I mean, you asked me about this timber and the reality is that mass timber is a total game changer. And if you are serious about trying to achieve anywhere near carbon neutrality with tall buildings, now when I say carbon neutrality, I mean as a total carbon equation, not operating energy, but to the materials themselves, embodied energy. The only way that you could ever come anywhere close to that would be to build as much of the building out a mass timber as possible. And so mass timber is a game changer in the industry. It's a complete game changer. It's the only material that doesn't require too much energy to produce. It's quite happily happy producing itself for 20 years as opposed to other materials. But better than that, it actually sequesters carbon out the atmosphere whilst it's producing itself as a building material for us to use. 


So I mean, that's a little simplified. Of course we do need energy to create mass timber from trees, but still that energy profile is much lower than steel concrete and other materials. So it's a game changer. I mean it's a game changer in that we are now farming building products. That's the way that we need to look about it. Of course, it's got to be part of that whole sustainable forestry planting water trees. But like any crop, it's a crop. It's a farm crop. And that's why it's a game changer for tall buildings and the building industry as a whole. 

Adam Jones (04:34): 

So what are some of the benefits in of mass timber in the tall building construction, maybe mid-rise and maybe the nuances even as you go higher, higher than that? 

Antony Wood (04:45): 

Well, the benefits are fourfold. The first is the sustainable carbon energy benefits. So we've talked about that. The less energy to produce the sequester of carbon out the atmosphere. So there's number one. Number two is the potential speed and cost efficiency. Yeah. Now don't forget, this is an industry, a sub-industry, mass timber, which is still relatively in its infant. Yeah. But the potential to get on top of that and economies a scale is start to reproduce this, produce this material in a much more efficient way is massive. And then the benefits of its efficiency on site. Yeah, I mean it's incredible seeing these. Now admittedly in the US we're probably, I think we're up to about 20 stories. I think ascent is maybe 18 stories. 


So we're not super tall yet. But it's incredible to go on these sites and see six people assembling the whole building. So the scenario is interesting because you speed up the construction. If you are saving three months off a 20 story building, think what you could save off a 60 story building. And the savings are really predominantly about a construction loans. I mean, if you save six months or 12 months off the construction time, it's not only cheaper labor savings and all the rest of it, but a lot of developers go into debt for take out loans for this construction. So the interest on that is massive. So number one is the energy profile, the carbon profile. The number two is the cost and efficiency savings. Number three, massive. I mean probably the biggest to start with is the human benefits. It's the biophilic human benefits, again, scientifically proven that people want that connection with natural materials of which mass timber is apart. 


Again, scientifically proven that people in these natural environments are happier and that has direct financial benefit, whether that is able to sell the apartment at higher price or I'm an office, I'm a business owner and my employees are more productive. So that's the third one. By way, it's probably more than four, but we'll stop it for, and then the fourth one is what I call the consequence or knock on benefits of this choice of mass timber. For example, mass timber is light. So the choice of mass timber has a positive knock on effect on other systems in the building. Most notably, the foundations mean, one of my favorite stories were mass timber, the meos in which is the tallest old timber building in the world in Norway, has some concrete in the upper floors. And I remember at one of our conferences, someone asking, the owner, developer was presenting on this building is it was just me building the world's all tallest old timber building. 


And some smart alec put his hand up and said, yes, but there's concrete in the top floors. And the owner developed said, yeah, we had to put some concrete in, otherwise the building would've been too light and might have blown away. I mean, it was being facetious, but that concrete's there to make it a bit heavier and damp it down because timber is so light. I mean, there's a project in Norway that's put 20, maybe not 20, but it's put x number of stories of residential mass timber over an existing shopping mall from the 1960s. Think about that in terms of your carbon equation and reinvigorating cities. You got this crappy old, okay, I better not say that might been nice, but I don't think so. This shopping mall or a car part from the 1960s, it built whatever, a dozen stories of residential over the top of it on the existing structure because the mass timber was so light. 

Adam Jones (08:51): 

Yeah, there's so much in that. I might just add one to it. It was just popped as you were saying that it was, I remember I used to be a concrete engineer and used to look forward to 80 story buildings because you just design one floor and then if be a repeat floor for the whole way. And I feel like that is much greater and much bigger deal in offsite construction is the idea of repeatability of typical floors. Because the first level, and when we speak to people on the podcast here, it's always the first level where you're sort of learning and you're figuring things out the second, and then you really start hitting speed on level three, four, and five. Then if the job stops. Whereas for highrise buildings, you just go on and on and on. And then the speed of construction can probably reach new levels. What are your thoughts on that? 

Antony Wood (09:35): 

Yeah, absolutely. And I mean it's interesting that you pick up on the flaws. Cause actually the flaws are where it's at. And a few moments ago I kind of implied that we could be building hundred story buildings out of timber. And the reason I say that, I mean really the timber, the biggest drawback to timber, the biggest drawback to timber is the cross dimensional area to achieve the structural capacity of the member. It's not that timber's not strong enough. And even the fire, I believe that we, we've resolved that. But the reality is that the cross section of timber that you would need to achieve the same structural aim as in steel is going to be bigger. And then you've often got a sacrificial char layer on the outside of it. So you lose floor area. And if you are going up hundred stories, that has an impact. So maybe this sensible solutions in the future is that we stick to concrete, I'll steal our composite construction for the vertical dimension. But the point I'm making here is you take a tall building, 80% of the weight of that building's in the floors, it's not in the columns, it's not in the bracing, it's in the floors. So we just switched from concrete to timber, mass timber for the flaws. We can reduce over 40, 50, 60, a hundred stories. Then we can reduce the weight of that building. Very, very is significantly. 

Adam Jones (11:08): 

Yeah, a hundred percent. That's so good. You might have already mentioned a few, but can you mentioned some of the most interesting and innovative mass timber buildings that you've seen in recent years moving into this space? 

Antony Wood (11:20): 

Yeah, sure. Yeah. Well, okay. Alright. I perhaps surprise you by saying that a lot of these buildings are not that innovative at the minute. I mean, especially here in America, you wouldn't even know they're frigging mass timber buildings. Cause of course they're covered up and they're covered up and all encapsulated. So it's a shame really. But you have this beautiful material because of anxieties over the fire code, they're often encapsulated in gypsum and from the outside you wouldn't necessarily know, just sounded recline towers. So it is a little disappointed to me how the real potential of mass timber is not yet being delivered. But there are projects I think that do start to get to that potential. So I've mentioned in Norway, I think it's in incredible building. It's totally mass timber. I mean mass timber cause mass timber bracing, mass timber facade. I mean that was interesting, that same conference where the smart Alex says, Hey, you got concrete in the floors. 


Someone has asked, well how can you club this thing in timber? It's 20 stories, 20 plus stories. How can you cla it in timber? And the Norwegian guy says, we got Steve churches that have been around for a thousand years in timber. I think everyone thinks you've got to get up there every five years with a bucket of Korean soap trying paint this timber to protect it. And it's just not the case at all. You mean he said, we do have to get up after 20 years, but that's to ensure that the fire retardant aspect of the timber, the impregnation are still working rather than timber's not a very, it's a maintenance head material. So I think the ANet is an incredible project. 


I think this project to Carol Doman that I talked about in Holland is incredible. This vertical extension over an existing six story shopping mall, the Sarah House in Sweden, it white architecture building is just beautiful. It's beautiful. And it's a hybrid building steel timber because they've got this huge conference center at the bottom. So it's a wide spann plate space and a building. And then it's a vertical building. So for example, they've got these trusses in the wide span place. I know you've seen them, but they're beautiful because they've got the timber in acting in compression with steel rods in tension. And it's how to do it, let the material be where it wants to be in terms of its performance. You got a project going on there in Australia, which I think is, I dunno what stage it it's at, but I Atlassian, 

Adam Jones (14:16): 

I was happy to see, hear you say that it's a ripper. It's ripper is a term in Australia for something we say really, it's really awesome. But yeah, 40 stories. It's got a steel exoskeleton and essentially four stories of mass timber buildings stacked up on top of each other with a concrete transfer deck. So it's a really interesting way of managing the fire, separating the fire, and you can have a bit of exposed in between. So it's a really highrise building with a fair bit of exposed timber and it's quite a brilliant design, but it's awesome. Yeah, yeah, 

Antony Wood (14:49): 

Yeah. Well there go all three materials kind of working in symbiosis, which is great. So I think that's shop architects out in New York that design that. So we're excited about that, seeing that and the diagram grid and everything coming together. Yeah, there's four, let's stop there going all day. 


Adam Jones (15:11): 

I imagine once you see a few go up and it's like, oh, who's, who did the fosbury flop? I'm thinking they're just shooting from your hip a little bit here. But Dick Fosbury and whatever Olympics it was with the high jump, everyone's jumping face first in the high jump, then the first person does the fosbury flop, then a year later everyone's doing the flop because they figure out it's possible. So maybe as soon as we see a highrise application, then all of a sudden it expands exponentially in a sim similar way. Hey. 

Antony Wood (15:42): 

Yeah, absolutely. Yeah. And I think that's happening. Mean we got some problems. I mean, it's ironic because, I mean, I'm from England originally. I've built out a house out of brick and block we have done for several hundred years. But here in America, a lot of the buildings for 200 years have been built out of stick frame timber construction. And yet that switch to mass timber has been two, three decades behind Europe and other places. So they're kind of struggling to catch up really in terms of supply, trying to meet demand for mass timber for multi-story buildings. But it definitely is gathering pace here. 


But again, and the code's catching up, we're starting to see the code support now a bit more use of the material of the systems. One thing that worries me though, if there ever was, God forbid, but if there ever was a fire, now fires happen in tall building. Fires happen in buildings all the time. And I'll be honest with you, if you are ever in a city and there's any kind of natural disaster, earthquakes or other things, you want to head into the modern design tall building, when you get a lot of disasters, the tall buildings are the ones modern designed. Look at what's just happened in Turkey. Those aren't tall buildings that they're kind of 10 up to 10 story suddenly built concrete buildings that are killing people. But fire is a different issue. And so it's kind of perception. I talk about maybe you're too young to remember the towering inferno. 


The towering inferno did for high-rise buildings, what jars did for sharks. I mean, I'm 53 now and I'm still sh*t scared of going in the sea because I watched Jaws as a 10 year old or eight year old and it terrified me. And I still remember the towering in front of, and in all seriousness, look at what happened with, I mean, by the way, Grenfell Tower in London, the Grenfell Tower fire set back mass timber in the UK by maybe 10 years. And there wasn't an ounce of timber in that building. It had nothing to do with timber, but it suddenly is projected into the public conscience. This fear, this issues of a raise that should never be raised because that building didn't perform. It was inflammable cladding on the outside and it just whipped up the tower. But then suddenly people make the association, well if we're building buildings out of flammable material, what gets more flammable than timber? 


And so we'd only need one of those tragedies to happen in the mass timber world. Could even be a building under construction it not even occupied, which is the biggest fear risk of course while it's under construction. And that could really set the industry back, possibly could not even recover if there was loss of life. And because there's a lot of naysayers in this industry and a lot of people that are saying we should not be building buildings at a mass timber, but we have not faced the fire challenge. And if that did happen, they'd be the first out of, from a popup about the parapet to say, we told you something 


Adam Jones (19:17): 

On Grenfell Tower. I believe it was no sprinklers either. So it was just a lot of the things you'd have in mass timber buildings not there. And I'm sure what you're saying is we're all saying who advocates in mass timber, it's not just be cowboys and just don't care about fire. It's more like have a reasonable, like you do for any structural engineering, you're not making it zero risk. It's like not making your speed limits five kilometers an hour and driving around with three feet of steel, protecting everybody. It's like what is a reasonable level of risk bearing in mind that we're trying to design sustainably and improve the industry going forward as well. So 

Antony Wood (19:57): 

The other thing that's interesting about that, Adam actually is post, I mean, most buildings when they've under experienced trauma in that way, they're completely unoccupied, unable that they're structurally compromised and there's no alternative. But after an earthquake or whatever the building comes down. But timber also has another potential because timber has a lot more flexibility to replace a actual elements of, it's a lot easier to cut out a timber or replace a timber column or a shear wall than it is with steel and concrete. And again, I like my stories, but a few months, months ago, we've got a lot of funding from the industry for various projects here at CG Bridge. But one of 'em is we got this project funded by both the timber industry and the steel industry on steel timber hybrids. And we got this conference a few months ago and all the world experts came and spoke, but we had Andrew Wall out of London come and talk about a project he'd done in London. 


It was timber steel in hybrid, but it was mostly timber. And then after about four, five years, the tenant or the client for the building changed and it actually turned into a school of architecture and they decided that they needed a new stair in a position where there was not a stair. Now you think about it's say a 10 story building, how difficult would it be with concrete floor to put a stair? They put it in the weekend. I mean they cut out the floor plate, the timber, and then they used that timber in the intermediate landings and they just winced it up and they put in this stair in almost a weekend, cut it out, this love and put it in. And there's a great flexibility about mass timber as well. 

Adam Jones (21:54): 

Yeah, that's so good. So what do you see as a sort of a blue sky where things are going in the future of our cities, not necessarily just mass timber, but it could be considering all the new technological advancements, offsite construction and modern methods of construction or anything that's happening. Where do you see everything going? 

Antony Wood (22:15): 

That's a big question to finish with and then, okay. Alright, alright. Okay. Well I I'll try and give you a quick mean, we spoke a lot about, Mass Timber spoke a lot about tall buildings. I mean actually when I met my most hyper critical, I'm pretty critical about tall buildings. I think most tall buildings around the world tend to be either just completely commercial boxes or gratuitous forms of sculpture. I want an icon and I look like this and that denies sometimes hundreds if not thousands of years of vernacular tradition. And I believe that we need to be looking for local responses, but for all buildings, but tall buildings as well. I believe there is an Australian tall building and African tall building, American tall building, and they're not all the same. Whereas, I mean they're all designed to a global pilot. So I think that the industry needs to head towards far more thought going into what generates these buildings and how they perform. 


And so the kind of things that I'm seeing happening and encourage and we're encouraging at the council is not only the use of mass timber and advanced technologies, but sky, sky, bridges, green wall. I mean every single tall building that's built from tomorrow onwards should have public accessible space at the top of the building, preferably the roof, which is open, best views, cleanest enviromnent plantable with trees and vegetation and all the rest of it. So we're starting to see this, I mean I did my PhD on Sky Bridges 20 years ago, and at that point we only had towers and everyone thought I was crazy. Well, there are a hundred buildings now, multiple complexes of tall buildings linked at several levels bringing the horizontal up into the vertical. So short answer to your question, I don't think it's so much technologies that are going to change cities. I think it's our approach to buildings and trying to achieve a more three-dimensional urban configuration, if you like, rather than just urban planning tends to be just a two-dimensional plan with heights stipulated. But we need to think about the whole three dimensions and how we can maximize that. 

Adam Jones (24:37): 

Yeah. Awesome. Well it's been so good speaking to you today, Anthony. If people want to find out more about yourself and the things we've been speaking about today, where should we point them? 

Antony Wood (24:46): 

Very easy. www.ctbuh.org That's council on tall buildings and urban habitat org. 

Adam Jones (24:58): 

Thank you so much mate. That was phenomenal. Loved it. 

Antony Wood (25:01): 

Great, great. And we got it to 30 minutes. That was impressive. 

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