semester. And I want to just recognize the fact that as it is not only the final lecture, but also the students have just gone through this major push and have finished their final review today and finished their thesis. So I want to congratulate the students and thank them for that extra effort that is to come to a lecture on the day where you had to make all that, you know, I've done all that work. So it's great to see everyone here and I want to turn now to our distinguished speaker to introduce her. So let me just say, you know, Susan McDonald's has really led an effort of global ramifications on the conservation of modern heritage and so much more. But today we're going to focus on her work in the conservation of modern heritage and in particular on the conservation of concrete. She has recently published a book with Ana Paula Gonzales called the conservation principles for concrete of cultural significance, which was published just last year with the Getty Conservation Institute. And it is really a book that I recommend to all of you. And she has been at the Getty Conservation Institute as head since 2008. She's been heading the buildings and sites program where she oversees over 20 projects that aim to advance conservation practice internationally. And it involves research, field projects, training and dissemination. So really the full gamut. And as you all know, the Getty Conservation Institute really has set a standard for practice around the world. And behind, you know, I would say institutes, universities, they're really the people that are there. And so we really have to look to, you know, it's really Susan and her team that have done this. She studied architecture at the University of Sydney and then did a master's in conservation studies at the University of York and is a certified practicing planner. So really covering the full gamut of knowledge and disciplines that we often talk about as being the interdisciplinary range that goes into historic preservation. And she has used these skills to work in the public sector where she has been involved in a wide range of conservation issues, both at the strategic level and at the bottom up level working with communities, involving urban planning, development, economics, developing policies, and really thinking all the way from the policy, large umbrella level to the technical matters, that concern world heritage. She's long been, as I mentioned, interested in 20th century heritage and is also a member of the Dokumomo International Specialist Technical Committee and vice president of Ikamo's 20th century committee. So it is a great pleasure to welcome Susan McDonald to our program. And since nobody can clap on Zoom, I want to do the clapping for everyone and welcome you warmly to our program virtually. Susan, thank you for joining us. Hey, thank you for inviting me and let me get my screen organized here. Okay, and thanks so much for having me this evening. And I can't believe any of you are here given the fact that many of you have had studio finals today and theses due and probably many nights of no sleep. So it's a really great for me to be here and to see some people joining us and hi to all my colleagues and friends that I see on the screen that I've known for a long time. And thanks for asking me to talk about concrete heritage. And it's a heritage that I think that we're still coming to terms with and which is both being reviled and beloved and everything in between. And but regardless of whether one is a fan or not, concrete in various forms covers much of the earth's surface today. And so certainly warrants discussion on how we cope with the sort of over 100 years worth of legacy of this evolving and intensifying use of concrete in all its different guises and across the world. So concrete the most destructive material on earth and this was the really dramatic headline that was on the first day of the Guardian newspaper's concrete week that happened in late 2019. And it launched a probably can quite lively debate on the world's most commonly used modern material. And it's a really fascinating read as many of the responses it generated from the concrete industry preservationist and environmentalists. And concrete has been beleaguered with a negative reputation, particularly of late due to this growing awareness of its environmental impact as a result of the production of its raw materials cement and the development of so many sites and structures using concrete and implications for its disposal when it's reached the end of its service life. And statistics that came from various places but one of the ones that they cited in this Guardian story was between four to eight percent of the world's greenhouse emissions result from cement production are firmly casting concrete as the villain of modern materials. And there are calls for alternative models of development and the use of more environmentally and sustainable and less impactful materials. But concrete does continue to be used at a really vast scale in many parts of the world. The Canadian scientist and policy analyst, Vaklal Shmil provides some really extraordinary statistics of the amount of cement produced and concrete poured in the U.S. over the last hundred years. And these these images show some of these figures and the extraordinary amount of concrete that's already being used in China in the early 21st century. And his book Making of the Modern World Materials and Dematerialization examines the evolution of many common building materials from their production to their use and energy cost and environmental impact and implications for its use. And it's a pretty fascinating read actually. But current concerns about the environmental repercussions of continuing to build in concrete at the current pace has relevance for us in our discussions on the conservation of concrete heritage. We know that reinforced concrete, which is the principal way that the material is used in construction, has maintenance and replacement needs. And the vast scale of its use will within the next 30 to 50 years need an equally vast scale response. And when we think about future conservation needs for building materials that we are and systems that we are actually using now, I think this affirms the need for us to be contextualizing heritage conservation within this broader societal values and concerns that economic, the social and the environmental, as well as the cultural values, which is where people like me, you know, have engaged that are engaged in heritage conservation are typically more comfortably reciting. So concrete heritage has also been beleaguered with negative responses associated with the perceived failure of modernism. And the term concrete jungle is one that's very much used to describe the worst of urban life. And for older generations, a large scale urban renewal can also be associated with the loss of urban communities and historic fabric. So in many parts of the world, concrete heritage is besieged, and we're really struggling to gain recognition for it and successfully conserve it. And there have been a lot of very high profile losses over the last few decades, and even the last 10 years or so. And these are continuing on a regular basis. And if you look at the ECOMOS or the Docomomo at risk in danger, sort of alerts there, we see them on an almost weekly basis. So some of these demolitions that are shown here from the US and India and Singapore and Australia were buildings that were very hard fought by the conservation community and was and subject to varying degrees of public protest as well. And sometimes the reasons stated for these demolitions were lack of these demolitions were lack of fitness for purpose. Sometimes they were technical challenges being the culprit. But in reality, it's often driven by the potential for economically advantageous redevelopment and the fact that this heritage is still not widely valued. So the serious building in Sydney on the left, the driver for its change and threat was about government really reducing its public asset responsibility and adding dollars to its coffers through the redevelopment of the building to luxury apartments. Other buildings languished through a lack of care and Club Ross Seminary in Scotland where its obsolescence of use and the isolated location led to long term neglect and uncertain future and also associated with really large scale costs required for its rehabilitation. And then the Sunscar Kendra building in India is really languishing through lack of stewardship and poor repairs and people not knowing really know how to best conserve the concrete. So the story of the serious building I thought I might pause on for a moment because it shares a similar trajectory of many other public housing developments of the 60s. And many of these buildings were founded on quite ambitious social and architectural ambitions. This is a building that was actually located on a site of the so-called slum clearances of the 60s and 70s in Sydney. And the serious building was named after one of the first fleet ships that carried the British colonial colonists to this far off land and centred their new settlement down the hill from where the building now stands. And the demolition of the of the terrace houses that occupied the site previously were actually what triggered one of the most significant green bands or labour bands in Australia by the builders labourers union. And that was the act that actually catalyzed the Australian heritage legislation in the 1960s. And the fight was at that time for the urban fabric of the historic core of the city but also to retain public housing on the site of which much of that early urban urban development was. And now some 50 years later the fights the same. Although the government had largely won in this case with the public housing tenants of this harbourside part of the city gradually moved out to enable government to do a sell-off of the historic properties to private tenants through long-term leases. But what was interesting here was that the government underestimated people's shift in attitude towards the building and this type of architecture which had been actually abhorred by many signiciders from the outset. The quality of the building and the apartments that the apartment complex itself along with its rather lofty social ambitions eventually led the state heritage body to recommend listing the place. But in a really unusual instance the minister refused to proceed with the listing citing financial reasons and loss of income for government as a rationale. And this is a pretty sad reflection on the erosion of heritage legislation. So what happened there's another green band now there's a court case that's pending and the last social housing resident meanwhile was removed in 2018. And this is a story that's been repeated many times over in different parts of the world and has different results you know in some cases the building is saved occasionally public housing is retained more often or not the buildings are gentrified and sometimes they demolish so a range of different outcomes. So here are the typically cited challenges for modern heritage generally and concrete heritage specifically. First of all this lack of appreciation recognition and protection kind of obvious if heritage lies at the intersection of the past and the present and the future this is the area the most recent heritage is obviously where the support for heritage tends to be most contentious so the younger the heritage the less support it has and this has always been the case. But there's also an issue of having a lot of these large concrete megalithic buildings being you know undertaken on a very large scale and that's quite a characteristic for the post-war era it can be as I said mentioned before associated with large-scale urban regeneration and the issues associated with that. There's also a lot of it which makes it hard for people to understand why it might be important it's not rare yet and there are perceived challenges of functional obsolescence and challenges of adaptation. There are specific technical challenges the questions of durability and lifespan of concrete perceived extra costs associated with conservation and the fact that we're still learning how to deal with some of these technical challenges. So these things have also these are challenges that have been levelled at heritage of other previous eras and ones that for modern heritage we've actually been dealing with for about 25 years and there is a growing body of evidence of how each of these can be overcome but I think there's another factor that's worth noting that in in some places these buildings hail from an era of huge government investment and then the current downward trend in government ownership and the privatisation of services means governments are selling off these assets and that has some specific implications for this type of heritage. So where we have a reduction in government asset portfolios coupled with a reduction of government services relating to heritage policy and research and funding there are some other implications they may not want to inventory it and list it as is the Australian case I cited before and therefore if they're not protecting it they don't develop policies on how to manage it or spend the time working out how to conserve it they may not undertake the research that's needed for emerging areas of heritage as governments have in the past and so this leaves the private sector in a difficult position because they face community pressure to do the right thing and conserve it but they don't have some of these other areas of support and so therefore conservation becomes a reactionary process a situation that the heritage sector has long been trying to move away from over the last 30 years because in this case often everybody loses and I think it's true to say that right now the research and the policy and the information provision for concrete heritage is really coming almost entirely from the nonprofit the education and the private sectors they're the ones mounting the case and undertaking the research in this area. So if we come back to this issue of adaptability and obsolescence for new use or change to meet current demands for new years these are kind of list of typical challenges that are often cited for adaptability for post-war buildings and as well as there being you know a huge amount of building undertaken in the second half of the 20th century also had a great expansion of typo building typologies and this tight fit between form and function is often cited as problematic for the adaptation to new uses and there can be challenges related to energy management meeting new green building standards and these are challenges as I said before I think we've increasingly had good responses to and I'll return to them later but there is a high cost associated with the environmental social and cultural costs of replacement and this shown on the screen here is another really important concrete building with an uncertain future in Philadelphia the Philadelphia police administration building I think it might be the second example of the use of shock baton a precast concrete system here in the States right now with an uncertain use so here are some of the technical challenges that are often cited that make people fearful of this heritage they include questions of durability and long-term lifespan lack of knowledge on best how to repair them and extend their life the impact of the repairs and the preventative treatments that we might usually use for concrete on the appearance of particularly the exposed concrete buildings and as I think I mentioned before the fact that the repair industry is really undeveloped for conservation purposes despite the fact that the concrete repair industry is a multi-billion dollar repair industry we still have poor standards of concrete repair continuing and that's obviously not something we want for our historic buildings and we have knowledge gaps that need to be filled there's historic research that needs to be done on the development and the use of the concrete technical information on its material characteristics the concrete that the construction techniques that are used and how to repair it long-term behavior and preventative approaches that we need more information on those and there is there is potential to work with industry but the conservation sector is such a small sector within this much but larger industry and we haven't yet been really successful in getting industry's attention to try and resolve some of these challenges that are specific to historic buildings but I think it is becoming increasingly obvious that these problems are not confined to concrete restructures we just we may define as heritage these are gaps that we need to fill so that the vast quantity of infrastructure in concrete that extends right across the planet is repaired and managed in a sustainable way I think true it's true too that the tide is turning for concrete heritage we are seeing new and growing audience starting to like and even love this stuff there's a huge surge in interest and appreciation and popularity in different parts of the world brutalism is now the ultimate cool this is another one of the days of the guardians concrete week and a brutal beauty our concrete became the ultimate lifestyle concept and concrete seems to be everywhere right now you know we've got our perfumes our features in cool magazines like wallpaper you can even get yourself some cool concrete wallpaper to cover your timber frame walls like we have in california and pretend we're living in a concrete building so concrete is also particularly brutalism is a bit of a style commodity right now and if you really want to gauge popular opinion where else do you turn other than social media and instagram and i think it was really interesting when i punched in brutalism there's an sort of amazing number of sites of really enticing images of very cool concrete comes up onto your screen brute group which is another one so i'm a member of has nearly half a million followers which is perhaps not many in the tiktok age but it seems quite a lot for concrete heritage and the world heritage list it's now got an increasing number of really spectacular concrete buildings from all the different periods of the 20th century from antonio gaudi's sagrada familiar centennial hall in broclo in poland which is from 1913 buildings like the syni opera house right through to 1973 we've got whole cityscapes such as the core of lahav and brazilia university campfire and sites like unam in mexico city which it's got this absolutely spectacular collection of mosaic and frescoed concrete buildings we've got the serial sites of lakabusia and frankloin right and oscanema and campulia which are all mostly testament to these architects work in the evolving use of reinforced concrete so um let's talk about conservation and what needs to be done what can be done um what is being done to try and navigate and advance the challenges um to the recognition and conservation of this concrete heritage so i think one of the first things is really about expanding that the the toolkit conceptually and thinking about how we link conservation to these greater societal endeavors of sustainable development in response to the climate emergency and the concrete industry has been pretty slow to come to this table but they are now starting to um the now you know really overused adage of the greenest building is the one that is already there is one that has great relevance i think to concrete actually um given the increasing evidence of the environmental impact of rebuilding at the scale of many of these large concrete megastructures um that exist in different parts of the world demolition of major sites without extremely good reasons will increasingly be be seen as villainous as was posited in the the guardian article i've mentioned and but we haven't yet really understood what those real financial environmental or social uh costs of high-profile demolitions of sites like robin hill gardens shown on the bottom left here in the uk or the prentice hospital in the usa is the cost goes way beyond the financial it has to include the existence value um the environmental costs giving some of the staggering statistics that are now emerging so i was at a brutalism now conference in london in 2019 and there was one statistic that that really stuck with me and i wrote it down for betham and i think it comes from the chatham house think tanks study on concrete but i can't remember who said it and so i can't credit them and but it went like this um the new buildings the embodied energy of constructing the substructure which is invariably concrete equates to 25 percent of the energy cost over a 60-year life cycle now that's a really staggering figure and one i think that can only serve to cause a rethink at some stage as cities uh ever so slowly begin to make firm commitments to zero energy carbon targets by um 2050 and one of the things that helped make things slightly more interesting during my two-week hotel quarantine in sydney last november was looking out the window um that is captured in the photo on the right and watching the refurbishment of the 1976 amp building uh progress and evidently this was the first time that two-thirds of an existing core of a high rise has been retained saving uh this is their figure some 68 percent of the original structure and this is an approach that is going to be one that's increasingly used to meet sustainable development goals a city like sydney which has very ambitious 2030 um zero carbon type um targets um is increasingly looking at these types of approaches so with access to better modeling tools to properly equate existence value and environment from the environmental perspective and conservation perspective we may soon be better placed in our discussions on how we trade off these economic and cultural values when we're making decisions about what to keep and what can go and we might finally be able to adequately factor these other environmental social and cultural costs into decision making in a more quantitative way so i think um the heritage conservation um it often is playing out in a you know kind of battleground where the predominant economic model of infinite growth and its school development is in direct conflict with our planet's uh finite resources and sustainable development is kind of cast as the panacea for somehow navigating these two opposing and irreconcilable forces and and so where does conservation sort of fit in there and and do we need to be beholden um to be part of this solution of um and not part of the problem um i think conservation work is increasingly now recognizing this need um to be um to to be thinking um along the lines of appropriate environmental responses and to contribute to the sustainable development goals i think that's kind of commonplace now but this does mean that our toolkit has to expand to manage change in ways that conserves what's important about the place, observes these societal needs and manages the knowledge skills and the money that's available in different situations. So we need to be using these full range of options for our concrete heritage from recycling to repurposing and reusing or renewing and sometimes even conserving. So the image on the top right here um is from Korea and it's example of a new building using recycled concrete. Now the one on the left on the top is um uh to a before and after of Park Hill Flats in Sheffield which was a reuse and repurpose um project which did result in a lot of change to the facade in the first phase of the the work and they're now rethinking how they move forward in the attempt to to preserve this building as housing. A renewal on really large scales as as the example from Geronto on the bottom right is increasingly an option that is tackling a multitude of societal issues and values and sometimes conservation is the solution and is at the core of approaches such as the case at the Barbican estate in London. So all of these options need to be on the table based on what's appropriate in each particular case but I think it's also important that we don't get these things mixed up. They are different solutions for different cases and um and conservation in its fullest sense is is but one of them. So um the GCI's new um case study series book on Conserving Modern Heritage um is not just a celebration of select of successful case studies but that book is really trying to demonstrate how practitioners have approached and solved some of the technical conservation challenges that have been cited as barriers including for some of these large-scale structures such as the National Theatre uh in London, Inutte de Havita Sion in Marseille and the the first technical school in the Netherlands. Now all of these buildings share the challenge of important exposed concrete which is the hardest type of concrete to repair where they have aesthetic significance and the exposed concrete is part of that significance. Getting matching repair um is is is something that we're still not good at. All of these examples are from Europe and they have the advantage of strong heritage protection um the programs that within these that these where these these buildings are from have had um have been in place for over 20 years even more. They've got government support in some way or another for conservation mostly in the guise of technical support to the owners, strong regulatory requirements and this has enabled them to work through some of the technical challenges for their projects and occasionally they have access to funding as well. Um but but in cases like the first technical school in the Netherlands that that was cost was a really um an important constraint on that project and they were still able to manage a really high quality outcome. But beyond the case study um type of uh case studies that we included in this book which were really confined to the technical challenges there are some great success stories for dealing with large-scale concrete megastructures and this is one which I've used many times before apologies for those who've seen it many times before um but the well-known um Toronto Towers Urban Renewal Project in Canada I think is a really interesting example of a city embarking on a holistic and really visionary program to sustain a large portfolio of mid-century tower blocks and tackle a whole range of other urban um issues. It's the city of some a thousand blocks tower blocks between 1960 and 1980. I think as I said it's a very visionary project there's a lot of good information on this online um and conservation here is really a by-product but it is part of this much broader societal response as I said and I think the purists have perhaps argued that some of the change instigated under this project and might be one that we more advocate for in a pure conservation um sense but it was a huge scale project and it was dealing a whole lot of other economic and social and community and environmental and cultural issues and it was looking at significance bringing um a broad range of values across the these things across the um the whole area of the city. So um this year's Pritzker Prize um winners provide an approach to architecture which is grounded in recognition that we do need to grapple with this addiction to constant renewal on a planet that's in crisis um through their reverence for existing structures. So, Arlaka Tam and Jean-Philippe Fachon's work sits at the intersection of adaptation and creation and they have a deep concern for sustainability and equity for the next um generation and um if I can quote them um transformation is the opportunity of doing more and better with what's already existing the demolishing the demolishing is a decision of easiness and short term it's a waste of many things a waste of energy a waste of material a waste of history moreover it has a very negative social impact for us it's an act of violence. So whilst they wouldn't claim their work to be conservation per se they have advocated for social justice and sustainability for decades and their work is both uh I think very humble and visionary and provides really creative solutions for enduring challenges and and so they do share much of the aims of the conservation sectors more generally. So the much loved and mixed use development of the Barbican in London is another really interesting example of where conservation is at the core of its stewardship and that's a consequence of both good governance and um and great community support and here the listing process included the development of management guidance for the huge site and it includes both policies from the urban scale right down to the repair and the maintenance of the concrete the building is listed at the highest level and so the highest standards of conservation are required so the management guidelines that address the ongoing and sort of inevitable change um grew out of extensive community consultation and they seek really practically to manage the day-to-day needs of such a large site with such a high level of public interest and you can google their management plans which are online um there's a lot of information on how they've managed a significance-led conservation approach for a major site with thousands of occupants across multiple uses. The resulting amenity and integrity of the place is something that's greatly valued and has made it a really sought-after place to live with really real estate prices that that reflect that. Right now they are in the middle of some controversies with proposed changes to the complex being met with really fierce community opposition and there are currently calls for a new master planning exercise to help manage some of the demands for growth and change by some of the institutions that occupy the site. So many countries have for quite a while or just beginning to engage in a process to identify and protect and conserve their concrete heritage and have been um so some have been doing this for for quite a while. Our historic England or English Heritage was then known when they started has been doing this work now for over 20 years and they really started um working from the advocacy end um and protecting places hand in hand with honest um discussions about the conservation challenges that ensued and also how to go about solving some of the technical problems. So the broker on the left here was part of a promotional material that accompanied their listing program back in the early 90s and that went through an advocacy program where they went out to communities and really tried to seek people's opinion on what they liked, what they didn't like, whether it was worth conserving or not and at the same time they were doing these conferences on preserving um heritage and what the challenges were and then at the same time they were also looking at the technical challenges I said and then finally quite recently they've been able to produce um some technical guidance as part of their practical building conservation um series on on concrete conservation generally. So this is something that's sort of been having 20 years in the making and and a slow but successful burn I think. But not all countries have had that same strategic um and whole scale approach and they're still catching up or have had to go about it in a very different way. So um a recent European research project called INEVA this is just an example of some things that are happening now. They have just been through a process where they've attempted they're attempting to advocate for concrete heritage through the development of a list of 100 sites from European countries and this is um something that you can look at on the website and see what sort of places they identified and other places are still working out what how they might go about similar exercises. There is now a growing source sources of information on on concrete to fill some of the information gaps and these are just some of the things that we've done at the at the Getty Conservation Institute over the last years in an attempt to fill some of those gaps. We started with an annotated bibliography which we've had one addition to and we're in the process of updating that right now and that should be ready next year. I already mentioned the case study book was which was something that was some people said they needed examples of how to go about this work and we're doing things like translations. Currently we've got two translations underway from LRMH the the French agency who's been involved in concrete conservation for many years one of them on cleaning and one on their glossary for concrete deterioration and those will probably be coming out later this year sometime. And our most recent work as Jorge mentioned at the beginning was to publish this document conservation principles for concrete of cultural significance and the aim of this document was really to try and bridge the seeming disconnect between typical conservation processes and typical concrete repair processes and try and bring them together in an effort to provide some sort of navigable and step-by-step information for practitioners and stewards of concrete buildings. And the document which you can download from from the internet includes a set of a glossary and some flow charts to a decision marking and it and it really is kind of recognizing that there's still research that needs to be done so that we can have better materials and techniques for conserving these buildings but nevertheless it's providing us some sort of an approach in the meantime and it advocates for many of the steps that we're familiar with you know starting with an understanding of what's important and why going through a proper diagnostic and investigative science-based approach to understanding problems and thinking about solutions undertaking trials and mock-ups and using skilled and knowledgeable consultants along the way so it's trying to kind of as I said reconcile these two approaches that so far have been sort of sitting in different corners and there isn't a lot of information that brings them together. So what are some of the barriers to technical barriers to conservation and I mentioned some of these before but I just wanted to come back to them and to think about research. So this availability of sympathetic repair materials is one that's been cited many times. There are protection systems that are often used for concrete but they're often irreversible and there are issues to do with appearance and not knowing about their performance and their long-term impact that we still have. The costs of conservation work being more labor-intensive than standard repairs so that's kind of a cultural issue. Another one is you know this is requiring a more handcrafted approach to industrialized buildings and materials and more industrialized repair industry and then you know attack the lack of knowledge and the availability of skilled crafts people and contractors. So we do need more research and we also need as well as research related to technical challenges we also need more research and accessible information on the range of types of concrete and development over time as this greatly varied. The materials varied, the way they were used varied, the design and the construction techniques varied, the regulations affecting its use varied and standards of workmanship varied and all of these the characteristics that arise from these different characteristics affect how it decays and so we really need to be better at targeting our repairs to specific material characteristics and right now we're kind of talking about it as I have been as pretty much it's all the same and it's actually not. There are many similar characteristics but we do need to be beginning to be more specific. So for example if we you know sort of think about three phases of concrete development the late 19th and early 20th century it was really dominated by the use of patented reinforcement systems that were used under license. Iron was used initially rather than steel. The way it was being used was very much to imitate traditional building materials and then we move into the interwar period where the regulation building regulations start to come into use that brexit monopoly of the license systems and starts to set standards so you get a greater variation in in reinforcement systems and different approaches to it. We're getting new architectural expressions and forms that really are starting to exploit more the structural capacity of concrete and you know you you characteristic of that period of these very sort of beautiful thin walled expressions often coated with renders different painted finishes and then in the post war era where we have this sort of explosion of construction in concrete it's very much used as a material that deals with the need for speed and economy. We get new forms of architectural expression and structural uses and the introduction of more and more forms of precast a much greater variety of finishes and things so very different kind of forms of expressions and uses. So a couple of years ago the GCI started to think about research and how we might participate in this endeavor and we did what we often do at the beginning of a program we convened an experts meeting to look at concrete heritage and to think about what some of the research questions might be and you might recognize people you know in that photograph there but yes as I said the purpose of this was to really try and help us identify what's the current state of play in concrete conservation and and then what might be some research questions that we need to look at to advance this area of conservation and what might the priorities be and we did actually identify a number of need and and priorities and there all on our website where this report resides. So from that the priorities that we identified with these that we really needed urgently appropriate patch repair materials and methods we needed more information on what materials we should be using and how we should be using them there definitely was interest in and a need for exploring penetrating hydrophobic treatments for historic concrete because that is a way that for reinforced concrete you can prevent the onset of the carbonation front reaching reinforcement and rust initiating and problems and cracking and the cycle of decay exacerbating but we also thought it would be very helpful to have some evaluation of the performance of past conservation treatments to sort of help assist us in defining what best practice might be and for the materials that we might want to use and as I already mentioned this need to better understand and characterize historic concrete through time. So over the last couple of years we've been working to get some of this research off the ground and we have two projects that we are undertaking right now and one of them and they both relate to this question to patch repair and one of them is to really look at the performance evaluation of patch repairs in historic concrete and the second one is to then start to look at a comparative analysis of different materials that are typically used in repairing historic concrete. So the first project is the evaluation one we call it PEPs and it's really trying to as I said evaluate the performance of patch repairs in exposed concrete in historic buildings to better understand the design and specification parameters and application methods and you know eventually the aim of that is to be able to provide better repair guidance and we're doing that in partnership with Historic England and LRMH in France and we have some consultants from the US, Swiss Cheney, Elsa and Simpson, Gump and Hager involved with us here in the US. So there is a bit of a subtext here and one of the things that we're looking to explore is the conservation approaches that Historic England and LRMH have been following in the past and which has been very much based on a sort of craft-based approach that's been borrowed from stone mortar repairs and you know in the USA the approach has been very much more driven by ACI standards for concrete repair and so you know what are these different approaches, what are the outcomes and the successes and failures been and so we were really interested sort of exploring these and some of these changes some of these approaches have changed over time in these other countries but you know this gives us to have a look at you know how do they sort of like for like the spoke approaches compared to proprietary or standardized approach which is actually what happens in practice and you know are there some conflicts between what conservation might be advocating versus the concrete repair industry standard so it was giving us an opportunity to explore this a little bit in these evaluations of past repairs over the last five to 25 years. So this work as I said gives us an opportunity to sort of compare these approaches, what's working, what's not, are the agencies involved giving the right advice, how do we bring concrete repair and conservation approaches closer together when we're talking about materials and techniques. And so the way we've gone about doing that is to identify 30 case studies, 10 from each country where we have undertaken from preliminary in situ non-destructive investigative evaluations of buildings with that have sort of had undertaken repair with a kind of conservation minded approach undertaken and the case studies have tried to sort of get a range of different concrete buildings from different periods and some variability in environmental conditions and so on and then the next step is to undertake much more detailed evaluations of 15 case studies five in each country which are laboratory based work and we're in the process of doing that. We were meant to be doing all the site based work last year but nobody did much site based work last year as we all know so we're a little bit delayed on that. All of this relies on us having good data on how the repair solution was developed and implemented and then access obviously to being able to do destructive and non-destructive testing in situ and in the lab for the more detailed work and as well as being able to sort of have some information and look at commonalities to see if we can glean from this better recommendations for going about different repairs and approaches can we also just develop a simple or practical let's say development of a methodology and diagnostic techniques and tests that people could be using to assess the performance and the efficacy of concrete repairs in the conservation context and also we thought that this is inevitably going to lead us to thinking about the identification of future research needs. So that work is ongoing as I said you know we plan to be at a much further ahead than we are but COVID is rather slow to stem but we are still going and hope to get back to it soon and the second piece of research work that's being undertaken at the Getty is not at the same stage as this other work. So meanwhile as we work out what to do with the concrete of the past the concrete industry and innovators and architects and engineers and others that are thinking about the concrete of the future and there's all sorts of really fascinating work happening to reduce the environmental costs of production of cement and how we use it and I don't know much about this so there are others that and other places to read about that but I think it's it is interesting to see this research into the use of alternative cements different types of reinforcement materials and admixtures to achieve more durable materials they could have implications for conservation as well I think there's interest in looking at creating lighter more malleable materials for ever expanding forms of architectural expression and also they're trying to sort of do this with an effort to reduce construction costs and environmental costs I said all of these things on the table and as I said at the beginning the concrete industry is finally starting to respond to some of these greater environmental concerns and there is recognition that the cement production process itself needs to be rethought to lower greenhouse gas emissions so all this work on the innovation that to innovate the use and production of concrete I think is going to be really crucial if it's still going to be used on the scale that it currently is today so if we come back to think about the legacy of concrete of the past and where preservation might fit I thought the recent launch of the the American Society of Civil Engineers annual infrastructure report is always fascinating it was on PBS the other night and made me think about it again and it's probably worth looking at and this year they gave America's infrastructure a C minus and if you go in and look at these reports it breaks down into all different types of infrastructure like roads and dams and it includes bridges many of which are concrete and a very serious subject particularly given sort of the catastrophic collapse of the Miranda bridge in general a few years ago which killed 43 people and that's a type of you know pre-stressed and pretension concrete we haven't really started to think about in conservation terms and I think there are some big challenges coming but bridges get a a C in the report and inside the report it says that 42 percent of bridges across the US are over 50 years old and 75 7.5 percent are structurally deficient but what I thought was really interesting was that preservation is specifically mentioned as a strategy for addressing the works deficit for this infrastructure and that's is seen as part of the solution to this large-scale work and these are this is a page from their summary it says you know how do we how do we how do we address this problem and here are the solutions and there were two others that dropped off the bottom of the page but you know second and third were prioritized rehabilitating and preserving bridges in fair condition develop a balanced approach for our current aging bridge industry where preservation rehabilitation and replacement are necessary so I think it's a sort of interesting indication that preservation is beginning to be seen more as part of the solution to these larger to these larger issues and societal challenges but we also do need to bite the bullet and start to offer up some positive ways forward from our sector as well so we've still got a lot more technical research that needs to be undertaken to tackle some of these long-standing problems that have been well identified for concrete heritage the work that's been undertaken to date is really piecemeal and ad hoc we haven't seen much in the in the way of practical advice to deal with common materials including concrete but I as I said earlier on I think framing conservation within the broader range of values is also important so recognizing that places can be host to multiple values beyond historic or the material is increasingly being recognized and is important but also vice versa recognizing that conserving these cultural and these other values can meet other societal objectives and fulfill some other typical environmental and social and economic economic sustainable sustainable development goals that we're all now obligated to attend to so I think there are some reasons to be optimistic of the future of our concrete heritage we've kind of gone through these processes of of generating recognition for and conservation of places from the early 19th early from the early 19th century the Victorian period early modern places they're all now accepted as being worthy of conservation and so as this sort of cycle of emerging heritage being beleaguered and besieged moves in through time it's the concrete heritage of the later 20th century that is both challenging us right now but also increasingly is beloved and conserved and being celebrated so I think concrete is a material that has been beloved and explored and exploited and enjoyed for the last two centuries vast areas of the planet are now covered with it and I think it's going to be really fascinating to see how we address it and deal with this legacy on the scale that we are now being required to in the future and I've gone longer than I thought and it but it's the end of my day and I just wanted to finish here with one of my favorite concrete buildings at Sock Biological Institute here in California and say thank you I hope some of you are still managing to stay awake at the end of your arduous week and thank you so much for for having me here to be with you today thank you Susan thank you for the wonderful talk much appreciated I will like once again clap for everybody else really really exciting to see you broaden the broaden the the discussion about conservation and the way that you have I want to invite everyone to either maybe there's the chat function and I would just invite you to write on the on the if you just write the word stack we will stack your question and I'll get to you and I'll call on you as we go you can also raise your hand but I think that that stack just keeps things in order and I can you know go so that we know who who's first so to speak as everyone and you're all by the way invited to turn on your screen or your you know camera just be aware that you know it is being recorded so you consent to being recorded by turning on your your camera while everyone gathers their thoughts I thought I maybe could get us started and just ask you a little bit about this this question that you raise about scale you on the one hand say told us you know we have this major problem the world's built up out of concrete it is all falling apart we have to do something to it and yet conservation is only a very small part of it and therefore of culturally significant buildings is a small part of it and therefore we can't get the attention that we need from the industrial partners that could invest the large research money into this to to really move ahead with some with with with coming up with some solutions to the very questions that you that you raised so how in your mind can we expand the the the practice of conservation to and perhaps encompass some of that other heritage such that we could begin to take on some of that some of that larger world that would and in scaling up begin to be at the table with let's say civil engineers and other professionals and ASCE who are having these conversations is that one way that you see it or is another way to federate all of the culturally significant buildings which seems to I wasn't clear which which path you were you were kind of advocating for because it seems that a lot of the work that the is doing is trying to kind of identify and gather similar case studies around the world to kind of come up with a common strategy for all of these so it's it's qualitative it's but there was the sense that that could also be quantitative that in a sense you could get let's say 7000 culturally significant buildings with similar problems and do a you know data comparative analysis there and be able to make the case that look if you industry comes up with a solution this could be applicable broadly and there's a market there and so on because you did mention economics there so I was wondering maybe there's a third path but those are the two that I could see in your talk which which of those approaches do you see yourself in the Getty kind of really seeing more more of a more more of a future or more of a better path forward if that if that makes sense well I think you sometimes need to work from from both sides because I think one of the reasons that often I think it starts it's super it's sorry let me start again it's super helpful when there are regulatory frameworks to start to protect the stuff that's not yet well understood and is really hard to therefore find ways to address so I think the English example has been really interesting because government went out at the beginning and said you know we think these things are important and we're going to invest in working to raise their to help people understand them and and maybe end up liking them and then we're going to also invest in working out how to conserve them and we're going to invest in perhaps thinking about providing solutions to some of the technical challenges which might be a barrier to conservation so that's kind of a traditional way that heritage kind of happened you know it's a it was particularly at the end of the 20th century I think that's kind of the model that we face but I think what's really interesting is you know in the 21st century where we've had you know much more focus on sustainable development and this recognition of the responsibility that we have to the environment and the way that we think about development and the production of place and the built environment and that we kind of have to think about it more responsibly you know whilst that was all happening this thing was happening as well and so we are starting to and have been thinking about and advocating for a long time let's work out what the what the cost of replacement is and so so that in fact so that in fact it might be on occasions that it's not just about the place is culturally significant it might just be a better solution to conserve it for environmental reasons or economic reasons or because the community likes the public space but it's not yet recognised as heritage so I think these things can happen in different ways and different and different places and we're just seeing a shift in the way things are being moved and generated so I wouldn't say that I would advocate one or the other I think what's really interesting that there have been these these approaches and at some point if you actually really want to say that some of these places are so important that we really want to conserve them in a more traditional conservation wise the fabric is really important the materiality of of them is really important you do need to think about well what are the techniques to do that somebody needs to work out well how do we go about doing that and do the research and come up with the solutions that meet those sort of you know traditional material approaches to conservation but that doesn't mean that there aren't other approaches that might be appropriate for places that are less significant or where the significance is a combination of different values which is why I thought the Toronto Towers one was so interesting because they said well look it's interesting from a point of view as being concrete heritage but it's got it's there are landscape values there are urban planning issues there are community issues there are facts that we need high density places that we we've got um environmental um energy management issues that we have to think about so all of these things came together and so you know I think conservation is moving from being much more siloed into something that is kind of more connected and and needs to be so I would say for for us at the Getty is an organization that's a non-profit organization sitting in California that's not attacked attached to um government or governance and um policy thinking what we can do is sort of think about um things from from from different levels and I think that's what's traditionally the Getty has done it's thought about it from the technical issues bottom up and solving technical challenges but it's also thought about some of these larger um philosophical or intellectual and contextual things about where does conservation fit and how do we have a seat at the table and how what role it it may play and you know that was sort of the the question that that you know Erica was we were working on with Erica in the values book it's sort of looking at this thing in different ways so I think that um that that you often need to be tackling at these sort of sort of different levels so I would say that you know for the Getty without a with an independent role if you like without being attached to any particular government or raising these questions that policymakers can then think about is important but then also we ultimately do need to know if we want to keep some of this stuff um we are going to work out how to technically address it and these questions that we're interested in is how do we prevent the ongoing decay of these buildings um like you know the the surface of the one I'm sitting behind me if you're a government asset manager and you've got 20 of these towers and you want to think how do I retain my building stock for the next 30 years instead of having to replace it we're interested in the same question actually how do we how do we prevent ongoing deterioration and and and and can continue the building to perform in the way that we wanted to so I think they're over there are there are overlapping areas of interest but what we've had trouble dealing with or or dealing with it on the technical side in terms of getting industry involved is kind of getting the critical mass of it but I think that's kind of it's coming closer to closer as it's it's becoming more obvious to industry why some of these questions need to be thought of beyond you know these cute little people in the corner that do this thing called conservation but I don't know if that really answered your question but um yeah dovetailing on that there's a question from Rory Hyde and I wonder if Rory would like to um ask the question live or you know Viva Voce otherwise I can yeah hi go ahead Rory I had a question about the position that preservationists often leave themselves in in advocating for the saving of buildings and I'm thinking in this instance of projects in London like the Balfront Tower or the Trelley Tower by Goldfinger where which were social housing buildings but then in advocating for the building to be saved they somehow are complicit in the process of privatization of kicking out the social tenants of selling the buildings in order to support their renovation and so you end up in this very difficult position where you're advocating for the buildings but you're perceived to be opposed to the continuing use of these buildings as social housing and I wondered if there's a way that those two positions can be resolved. Well I might argue that the present conservationists weren't advocating for the loss of social housing I think um in I think when I look at the serious example I mean the example one of the things that the conservation community was advocating for was the saving of the building as public housing so it was a combination of both of those things because that part of the city has been public housing for um you know over a hundred years now and the loss of that social significance in community was considered really quite significant so I think um you know gentrification and conservation is a much bigger topic in question that we can that we can possibly deal with. I think the Balfront Tower case and the Trelley Tower ones were really interesting because as you said they were public housing that ultimately became part of government's larger policies for allowing people to you know they many of their public housing blocks have various programs for either allowing owners to buy into them and selling off a certain proportion of them to the to the pub to the private sector to to pay for upgrades and that's kind of a housing policy. I think um you know I don't think that was the the conservation sort of community advocating for that but so there was a I think it's a little bit more complicated than that I guess and it's a big question that's hard to answer in the context of right now perhaps if um if that's not too big of a cop out. No no that's terrific thanks. Yeah I mean I think the Balfront Tower okay I mean I'm trying to remember which ones were Trelley Tower was really interesting because people were advocating that that needed to be redeveloped or demolished because it was dangerous everybody hated it it was you know a terrible building it had a million things wrong with it and when they did the community consultation with the people that lived there they said the real problem is that the lifts don't work and they keep getting vandalized and it's unsafe and we don't want to have to walk up and down the you know the stinky stairs and you know I've got a kid in a stroller and it's dangerous and I hate it and so the solution initially was to put a security guard and to put a secure door put a security guard and stop the lifts getting broken and then people actually like quite liked living there so there was it was you know there was a whole range of things that actually related to the reasons why people liked it or didn't like it beyond the architecture as well which was sort of interesting and um and complicated and um you know I think um the the um and and the same thing could be said for the Alexander Road many of those big housing estates that were listed first went through a sort of interesting challenge um in in that regard and some of them weren't conserved and listed you know some of them were um redeveloped in ways that the conservation community was upset about but they retained their uses public housing so you know they were sort of considered lost by the conservation community that retained a public use and other societal values you know endured if you like. We have another couple questions um I'm going to turn it over uh first to Mary and then to Norman who asked for the speaker I just want to say what a pleasure it is to have this zoom one of the silver lining is Rory is calling in from Melbourne Australia where he's professor at the university there and here we all are on this global conversation so thank you Rory for for joining us I just want to acknowledge that it and Susan's and LA we're really covering the the globe it's so wonderful. Mary please go ahead you have to unmute yeah. Okay thanks Susan that was really a great talk I enjoyed it um just one of your talking about bridges and agencies the Connecticut DOT is in charge of the Merritt Parkway bridges which are all almost all concrete there's two exceptions to that but you know it took years and I I'd say that the um the Merritt Parkway Conservancy really are the unsung heroes in this in that they pressured and pressured and pressured for years. You can see some of the very I'll do is upon brutal attacks on these poor concrete bridges but as they worked along with them you can start to see much more sensitive repairs coming in it was unfortunate there were some people selling materials that were telling them what to use that were not particularly good but if you drive down the Merritt Parkway you can really see the whole history of this it's really interesting. This is a side note when I was at World Monuments Fund we put those bridges of the Merritt Parkway on the World Monuments Watch in 2010 in part because the Conservancy said we need a stronger voice which kind of speaks to what Susan was saying earlier about kind of needing the the larger advocacy policy oriented approach as well as the technical approach. I think it's sort of iterative isn't it I mean that's a really good example of that iterative thing there's attention brought to it you know they you don't always start being particularly successful but over time things you know as more attention gets brought to it and more people recognize that it's important you you move forward I mean I think you know big some of those big public housing estates like Alexandra wrote in London are a really good example of that because you can see the evolution of repair related to different phases of recognition of conservation and listing and it's really amazing to see some of us you know it didn't start out well. Norman do you like to jump in please love to would love to let me take a let me take a shot at a different kind of answer to the question that you asked Jorge at the very start of the Q and A which was a big picture question about what the right broad strategies might be do we group these buildings together do we see the similarities and so on. I think part of the answer was actually Susan in the middle of your lecture when you said at one point we've made a mistake that we think concrete is all one thing and that it's an incredibly complex material and there are so many variations on it and therefore on on its physical characteristics and all sorts of properties I think I guess my answer to where do we go forward now based on the idea that we're doing things now that other communities within the conservation of buildings have worked on starting in the late 60s 70s 80s look we can look at the stone conservation community which we're sort of behind and the logic of that is quite reasonable many of many people in conservation still don't quite like concrete buildings but the younger generation does but I think the answer lies in not making the mistakes we've made before and if we look at stone conservation at the very outset the mistakes were two one that people were hunting for a way to conserve stone as if stone were one thing and until we absolutely subdivided it and characterized it in many different ways we didn't make any progress and the other mistake is extremely similar which was assuming that the problems of stone were then and concrete now are basically a problem and that's the same mistake that the medical community made 50 years ago thinking that they would find a cure for a thing called cancer and when cancer was subdivided then into a number of categories and really carefully looked at that's why we've seen progress in some cancers certain childhood cancers are totally different in terms of of success rates than they were 40 or 50 years ago others have been more resistant to it but it's it's this question of not making the mistake that either the material or its pathology is so simple and so much one thing that we should just hunt out the solution and I think maybe there's one more mistake that we shouldn't make again and that is something again tied up with a comment I think you just made Susan again about something about the precious little people in the conservation world sitting off to the side and saying it's time to do something and that is this mistake of not reaching out ourselves toward the groups you've mentioned like ASCE like ACI and I would add to that ICRI International Concrete Repair Institute which is a more reachable community as you probably know because it's it's really more contractors and material suppliers than it is engineers and by the same token ACI has lots of engineers but relatively few architects and almost no conservators involved and so on if we get more involved in those organizations and you know my pitch will be we should all go to World of Concrete but basically getting ourselves in there and in their faces and speaking their language to an to a sufficient extent that we can understand what's going on and understand how to change that community change its goals and show them what we need to and just one more thought I was delighted that you mentioned Salk as one of your favorite concrete buildings I also have favorites in concrete but I urge you to look at my favorite song which was a great hit in the UK in 1965 if you go listen to it on YouTube you will realize that you recognize it immediately but you probably never knew it was called Concrete and Clay and it was filmed with the band an obscure band called Unit 4 plus 1 performing it on the construction site at the Barbican so it is that it will become your new theme song so I urge you as soon as we're done with this you have to go onto YouTube and find Concrete and Clay 1965 I believe okay I'll go enough get a glass of wine and do that thanks thanks I mean thanks Norman I think that thing the specificity thing really worries me that we have been sort of lumping if I can use that all concrete together because dealing with a 19th century unreinforced concrete with you know low cement content and very different type of cement to the ones that are used 100 years later even in a 50-year period the cements are very very different the strength the porosity are different the reinforcements completely different they just behave differently and and I think we just haven't been specific and I think that's partly because it was sort of overwhelming and partly because it's the way the repair industry has kind of approached it you know we've kind of followed that you know it's all kind of the same right um but I think your point too about reaching out to industry is a really good one I know this was something that when I was first in English Heritage we tried doing and it was kind of scary because you know it's quite big and you know Norman and I did go to World of Concrete a number of years ago and it's quite terrifying because it's the first conference I've been to with 35 000 other people and you know all these dudes walking around and playing on big machines and things and there's like massive halls with just like a million things so it's sort of you feel so pathetic and insignificant and tiny it's hard to know where to start and how to reach out and there are some people at work in our industry that sort of cross over you know there are consultants sort of working in concrete repair who are very much involved in in ACI and then there's other two are involved in IPRI and they all seem to sort of like do this um and then like which ones am I with um and that's kind of scary too but so I think it's also been a bit of a lack of confidence in how how to know about going about that because some of the early overtures in the UK to both the contracting arms of people doing work and then the um the seekers of the world they were very responsive to it you know you could there was some initial progress and that then it kind of just got lost but but you know there are ways into it it's about finding that that kind of joint area of of information and I think Norman you and I had talked a long while ago about you know this question of the hydrophobic um penetrating hydrophobic treatment is probably an area where you can you can think about and and and do that and those recent um European research projects like the interval one have done that I mean in some I'm a bit worried about some of that actually because of you know industry there are as we know there you know they have their specific areas of interest but so I do think that there is great potential there and it's just we haven't had a kind of um community of practice that's been coherent or big enough to start to have the conversations or something I guess that's why it is we just haven't got to that critical mass where we well there's not somebody leading away to to to do that or knowing how to do that or feeling confident enough to do it I don't know that we should yeah we can go to world of concrete again one day that it was absolutely well a mindful of the time Susan I I want to thank you again for this wonderful talk and for um sharing all of your you know recent work with us and raising all of these important questions for the for the discipline for and for the work that that we all do so I really appreciate you taking the time to share your knowledge with us we all leave a lot richer with all this with all this uh uh knowledge in in our heads now and uh we really appreciate that so thank you so much and uh we we we hope to see you again in New York we owe you a dinner with uh with all of our students that'd be great I'd love to meet all the students all of you it'd be great well thanks so much for having me too thanks so much and if you if you don't mind staying on the zoom I'm going to let everybody go and uh we can just yeah