6th Holcim Awards 2020/21

6th regional and global competitions for projects and visions sustainable construction

...gives an impulse to continue my studies” Javier Estebala Alández, page 66 ...conveys a strong mess age to reduce the environment al impact” Dolathep Chetty, page 234 ...is a vital step forward in my career as a researcher” Priscilla Namawanje, page 184 ...is a huge motivation to keep on researching” Maria Rosario Ruiz Cabello, page 148 ...pushes to think outside of the box about sustainability for better communities” Tala Shelbayh, page 186 ...is a huge acknowledgement for what the client is aiming for” Wolfgang Kessling, pages 47, 220 and 256 ...is a stimulus to continue what we have been developing” Leão Lopes, pages 46, 174 and 208 ...attracts attention to issues in developing countries” Evgenii Varlygin, page 188 ...encourages others from our academy to participate in this type of contest” Juan Lamilo Muñoz Daza, page 152 ...appreciates sustainability without compromising aesthetics” Divya Jyoti, page 238 ...is an incredible honor and humbles me to be representing my country” Noor Marji, page 190 ...provides significant momentum to go ahead with this unique project” Leticia Alfaro, page 144 ...demonstrates the potential of designed ecosystems to address indoor air quality” Phoebe Mankiewicz, page 106 ...is special because this competition looks ahead over several decades” David Marshall, page 100 ...confirms the need for a new form of collaboration” Yufei He, page 70 ...is a great achievement for me and my project” Lorenzo Fernandes, page 232 ...recognizes that urban and social development should be deeply interlinked “ Pablo Goldin Marcovich, page 150 ...gives us more credibility to continue with our dream of sustainable innovation” Noor Shaik, page 102 ...can hopefully push my idea to another dimension” Annik Keoseyan, page 72 ...could be a good beginning to pursue sustainable architecture” Rionaldi Gunari, page 236 ...is an exciting opportunity to transition from research to large scale applications” Samuel Clovis, page 104 ...motivates to innovate new design methodologies” Shneel Malik, page 68 ...is a recognition for keeping people and the planet at the core” Jakob Dunkl, page 60 ...pushes us to design projects for sanitation, equity and social inclusion” Soledad Patino, page 230 ...acknowledges that our collaboration across borders promotes new standards” Azra Aksamija, pages 46 and 176 ...means an energy boost for our office” Maria Reinoso Guerrero, page 138 ...enables us to dream big” Diane van Buren Zachary, page 94 “Winning this Holcim Awards prize... ...is a refreshing recognition for our ingenious builders” Salma Samar Damluji, pages 172 and 200

Sixth Holcim Awards Regional and global Holcim Awards competitions for projects and visions in sustainable construction 2020/2021

Holcim Foundation for Sustainable Construction 6th Holcim Awards competitions Global Holcim Awards 2021 Regional Holcim Awards 2020 Holcim Awards prize trophies Credits Five posters each: Exhibition of the 33 Global Awards finalist projects in Zurich. Jury members who could not participate in person were taken on a virtual tour and could view the posters via an online platform (page 10).

Driving sustainability and circular economy 4 Target Issues for sustainable construction 6 Overview of all prize winning projects 8 Jury members and meeting 10 Award winning projects Gold – Switzerland 12 Silver – Colombia 22 Bronze ex aequo – Morocco 30 Bronze ex aequo – Vietnam 38 Commended projects 46 Jury members and meetings 48 Prize winning Main and Next Generation category projects Europe 52 North America 90 Latin America 132 Middle East Africa 170 Asia Pacific 216 264 268

4 The creation of the Holcim Foundation for Sustainable Construction in 2003 occurred at an auspicious time. The need for change was in the air, and there was a deep belief that the building sector must become a driver of sustainability. A pioneering spirit prevailed, setting a world-wide agenda to reorient environment-making practices for decades to come. A landmark whitepaper was already on the table, the 1987 Brundtland Report that called for “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” Up for discussion as well was the 1992 Rio Agenda that charted a comprehensive action plan to reduce human impact on the environment, along with the 1997 Kyoto Protocol mandating significant reductions of global greenhouse gas emissions. So much was clear regarding the broad recommendations for achieving sustainability. Driving sustainability and circular economy Edward Schwarz, Holcim Foundation 2003 Bringing building practices into line with international frameworks Yet these general principles were somewhat abstract and not specific enough for a sector with a significant ecological footprint. The operational lifespan of buildings consumes just under half of all globally available water, material, and energy supplies, while also generating nearly half of the total carbon emissions and waste output. What was needed were more tangible guidelines that would bring building practices into line with international framework agreements but be more detailed in outlining specific commitments to sustainability within the construction sector, beyond just paying lip service to the cause. Sustainability for the Foundation, in other words, had to be literally constructed tenet by tenet, target by target, and technique by technique. Amidst debates on which objectives for evaluating sustainable construction would be most effective, it was decided early on that the overwhelming lists of criteria from academic research and certification councils The need for change was in the air would need to be distilled to form a set of concise targets applicable at all scales of the building sector. Common to all of them was the threefold imperative that whatever is built has to perform sustainably on environmental, economic, and social registers. Regional interpretation and adaptability Accordingly, three issues were specifically identified that to this day have remained constant in the Foundation’s charter. Regarding the construction sector’s impact on the environment, what gets built must mitigate rather than contribute to carbon emissions. Regarding material and energy flows in the construction sector, what gets built must lead the transition from a linear to a circular economy of renewable resource use. Regarding the ramifications on people, what gets built must foster bonds and equity within society. As timely as these core targets are, to build sustainably is not a one-size-fits-all directive, insofar as each world locality faces its own challenges and has recourse to its own ways of dealing with

5 2015 2021 them. Place-specific solutions that allow for regional interpretation and adaptability to contextual particularities were therefore taken into account as a key criterion of sustainable development as well. For the sake of forging new pathways, the Foundation also places a premium on innovation from the very beginning over and above material- and energy-intensive building practices, insisting that breakthroughs in construction – including rediscovered traditional methods adapted to new circumstances – are at the forefront of making our collective habitats more sustainable. All in all, these interrelated concerns formed the basis of a new operational contract for the building sector, one that is as much environmental and economic as it is social and contextual in its scope. Keeping in mind that the Foundation’s sponsor is a materials enterprise with global reach, it was not enough to simply make bold statements. For the ambitious objectives – or Target Issues as they would be called – had to be taken up in the everyday practical matters of the company to set an example of best practice throughout the industry. The bottom line was that corporate aims would have to be aligned with those of the Foundation and vice versa. Through the synergies and dialog established, the company would eventually adopt an integrated sustainability agenda that even challenged its own modes of operation. This agenda ultimately included progressive milestones for reducing carbon emissions, increasing waste recycling, and embracing measures to promote human rights in all facets of the construction sector. To this day, resource circularity, net-zero emissions, and compliance with the highest of ethical standards are at the core of the ongoing mission of both the Foundation and its sponsor. Best practice throughout the industry incremental? Whatever the answer, systemic overhaul or tweaking the status quo, the mission of sustainability becomes more urgent day by day as a pledge that must be put into action. What is still on the table and up for discussion in boardrooms as well as on construction sites around the globe is whether the disruptive transition from business-as-usual practices to planet-compatible ways of environment-making will proceed in small or large steps. That is, will change be radical or New operational contract for the building sector Evolution of the Holcim Awards trophy The base of the main Awards prizes is made by Holcim Switzerland using EvopactZero – a climate-neutral concrete that includes recycled aggregate and a resource-saving cement. This innovative building material closes the material cycle by using both the fine and coarse elements of demolition waste. The fine materials are incorporated into the cement while the coarse materials serve as aggregates in the concrete mix. EvopactZero minimizes the use of resources, conserves landfill space and offsets net emissions through certified reforestation and wind power projects. Read more about the logo and the Awards trophies of the Holcim Foundation on page 264.

6 The Holcim Foundation for Sustainable Construction is committed to sustainability as an unconditional principle, asserting that environmentally conscious building practices require a mutually reinforcing interplay of the democratization of all processes pertaining to the production and use of the built environment. Although there is growing awareness of the need for across-the-board decarbonization, circularity, and equity, construction processes must be further recalibrated in order to make the building sector a driver of innovation in sustainable development in all senses of the term. To this end, the Foundation has identified five Target Issues as guidelines for sustaining the human-made habitat for current and future generations. These objectives provide an operational roadmap for all activities of the Foundation: evaluation of Holcim Awards submissions, expert roundtables, international conferences, research grants, next-generation laboratories, as well as best-practice publications. The five Target Issues for sustainable construction under the headings of Progress, People, Planet, Prosperity, and Marc Angélil and Cary Siress 1 Paris Agreement Under the United Nations Framework Convention on Climate Change, adopted in December 2015. Interplay of responsible ecological, economic, and social objectives Evolving understanding of sustainability in construction Target Issues for sustainable construction Place are critical to making the environments we build and inhabit truly future-viable for all terrestrial stakeholders. Progress Innovation and transferability People Ethical standards and social inclusion Planet Resources and environmental performance Prosperity Economic viability and compatibility Place Contextual and aesthetic impact In light of the compound challenges facing the building sector, the Target Issues have been periodically adapted since the Foundation’s inception nearly two decades ago to reflect an evolving understanding of sustainability in construction. Accordingly, the Target Issues require ongoing review in the future. responsible ecological, economic, and social objectives. In accordance with the Paris Climate Agreement1, the Foundation places a premium on the reduction of global greenhouse gas emissions in all construction-related activities to minimize further ecological deterioration. In keeping with the holistic cradle-to-cradle ethic, the Foundation also emphasizes the need for a circular economy of resource use at all scales, whereby what goes in and what goes out must be restorative and regenerative. In alignment with the need to govern the places we inhabit as an equally accessible social commons, the Foundation promotes

7 Progress Innovation and transferability Projects must demonstrate innovative approaches to sustainable development by pushing the envelope of practice and exploring new disciplinary frontiers. Breakthroughs and trend-setting discoveries must also be transferable to a range of other applications. Transferable innovations must comply with the principles of circularity and decarbonization, while demonstrating an awareness of the environmental impact of construction throughout a structure’s use-cycle. People Ethical standards and social inclusion Projects must adhere to the highest ethical standards and promote social inclusion at all stages of the process, from planning and construction to use, servicing, renovation, and decommissioning. To ensure an enduring positive impact on communities, proposals must demonstrate how to enhance the collective realm and how affordable and socially inclusive habitats can be sustained, including the fair distribution and management of resources. Planet Resources and environmental performance Projects must exhibit a sensible deployment and management of resources throughout their entire use-cycle. Long-term environmental concerns, especially in view of optimizing circular flows of material, water, and energy, should be an integral part of the design and construction approach to minimize greenhouse gas emissions, reduce waste, and promote the use of regenerative resources throughout the industry. Prosperity Economic viability and compatibility Projects must be economically feasible and able to secure financing, whether from public, commercial, co-operative or concessional sources, while having a positive impact on the social and physical environment. An economy of means in construction must be pursued in order to avoid the wasteful consumption of materials and limit carbon emissions. The products used as well as construction processes deployed must adhere to the logic of circular economies. Place Contextual and aesthetic impact Projects must convey a high standard of architectural quality in responding to the social and environmental urgencies of the present and those to come. With space, form, and aesthetic impact of utmost significance, the material manifestation of the design must make a positive and lasting contribution to the local context as a prevalent form of cultural expression. Cricket Shelter in New York – Research and development project, New York, 2018. Terreform ONE (Mitchell Joachim, Maria Aiolova, Vivian Kuan, et al.), New York, USA. Winner Holcim Awards Acknowledgement prize North America 2017. Legacy Restored in Niger – literacy center in renovated derelict mosque, Dandaji, Niger, 2017-18. atelier masomi, Niamey, Niger (Mariam Kamara) and studio chahar, Tehran, Iran (Yasaman Esmaili). Winner Global Holcim Awards Silver 2018. Secondary School with passive ventilation system, Gando, Burkina Faso, 2011-14. Kéré Architecture (Francis Kéré), Berlin, Germany. Winner Global Holcim Awards Gold 2012 and Better Building Recognition 2017. Grand Parc, renovation of 530 dwelling units, Bordeaux, France, 201416. Lacaton & Vassal (Anne Lacaton, JeanPhilippe Vassal, Frédéric Druot & Christophe Hutin), Paris, France. Jean-Philippe Vassal and Anne Lacaton have been Holcim Awards jury members. Articulated Site in Colombia – UVA de La Imaginación, Medellín, Colombia, 2014-15. Colectivo 720 (Mario Camargo & Luis Tombé), Calí, Colombia. Winner Global Holcim Awards Gold 2015 and Better Building Recognition 2017.

8 Regional Award Gold Chicago, USA Pages 90 and 108 Regional Award Silver Yellowknife, Canada Pages 92 and 116 Regional Award Bronze Boston, USA Pages 94 and 124 Regional Acknowledgement prize Tuscon, AZ, USA Page 96 Regional Acknowledgement prize Detroit, USA Page 98 Regional Next Generation 1st prize New York, USA Page 100 Regional Next Generation 2nd prize Waterloo, Canada Page 102 Regional Next Generation 3rd prize Tampa Bay, FL, USA Page 104 Regional Next Generation 4th prize New Haven, CT, USA Page 106 North America Global Award Silver and regional Award Gold Bogotá, Colombia Pages 22 and 132 Regional Award Silver Laranjal do Jari, Brazil Pages 134 and 156 Regional Award Bronze Bogotá, Colombia Pages 136 and 162 Regional Acknowledgement prize Quito, Ecuador Page 138 Regional Acknowledgement prize Canalejas, Mexico Page 140 Regional Acknowledgement prize Cordoba, Argentina Page 142 Regional Acknowledgement prize Mendoza, Argentina Page 144 Regional Next Generation 1st prize Manaus, Brazil Page 146 Regional Next Generation 2nd prize Resistencia, Argentina Page 148 Regional Next Generation 3rd prize Mexico City, Mexico Page 150 Regional Next Generation 4th prize Bogotá, Colombia Page 152 Latin America Global Award Gold and regional Award Gold Winterthur, Switzerland Pages 12 and 52 Regional Award Silver Prijedor, Bosnia and Herzegovina Pages 54 and 74 Regional Award Bronze Skellefteå, Sweden Pages 56 and 82 Regional Acknowledgement prize Hamburg, Germany Page 58 Regional Acknowledgement prize Vienna, Austria Page 60 Regional Acknowledgement prize Bordeaux, France Page 62 Regional Acknowledgement prize Siewiller, France Page 64 Regional Next Generation prize ex aequo Cádiz, Spain Page 66 Regional Next Generation prize ex aequo London, UK Page 68 Regional Next Generation prize ex aequo Zurich, Switzerland Page 70 Regional Next Generation prize ex aequo Brussels, Belgium Page 72 Europe 6th Holcim Awards winning projects

9 Global Award Bronze and regional Acknowledgement prize Hanoi, Vietnam Pages 38 and 226 Global Commendation and regional Award Bronze Sydney, Australia Pages 47, 220 and 256 Global Commendation and regional Acknowledgement prize Minalin, Pampanga, Philippines Pages 47 and 222 Regional Award Gold Lanzhou, China Pages 216 and 240 Regional Award Silver Shenzhen, China Pages 218 and 248 Regional Acknowledgement prize Shenzhen, China Page 224 Regional Acknowledgement prize Phnom Penh, Cambodia Page 228 Regional Next Generation 1st prize Mumbai, India Page 230 Regional Next Generation 2nd prize Mumbai, India Page 232 Regional Next Generation 3rd prize Samut Prakan, Thailand Page 234 Regional Next Generation 4th prize ex aequo Jakarta, Indonesia Page 236 Regional Next Generation 4th prize ex aequo Pune, India Page 238 Asia Pacific Global Award Bronze and regional Acknowledgement prize M’hammid El Ghizlane, Morocco Pages 30 and 178 Global Commendation and regional Award Bronze Chã das Caldeiras, Cabo Verde Pages 46, 174 and 208 Global Commendation and regional Acknowledgement prize Zaatari Refugee Camp, Jordan Pages 46 and 176 Regional Award Gold East Jerusalem Pages 170 and 192 Regional Award Silver al Mukalla, al Shihr, Yemen Pages 172 and 200 Regional Acknowledgement prize Bandar-e Kong, Iran Page 180 Regional Acknowledgement prize Kampala, Uganda Page 182 Regional Next Generation 1st prize Kampala, Uganda Page 184 Regional Next Generation 2nd prize Amman, Jordan Page 186 Regional Next Generation 3rd prize Freetown, Sierra Leone Page 188 Regional Next Generation 4th prize Basra, Iraq Page 190 Middle East Africa

10 Global jury meeting: “Remarkable progress since the regional phase”

11 A jury of nine experts selected the global prize winners in the 6th International Holcim Awards for Sustainable Construction in a two-day meeting on March 11/12, 2021. The 33 finalist projects from 25 countries were displayed as a poster exhibition in Zurich and were also made available via an online platform. Head of the Academic Committee (AC) of the Holcim Foundation, Marilyne Andersen, provided a “virtual tour” of the exhibition for the jury members unable to travel to Zurich. She is also Professor of Sustainable Construction Technologies, EPFL Lausanne (Switzerland), a member of the Board of the Holcim Foundation, and represented the AC on all five regional Awards juries in 2020 (page 48). “I’m very excited to be able to walk through this exhibition of 165 posters that bring outstanding examples of sustainable construction from around the world to life. It is remarkable to see the progress of many submissions since the regional phase of the competition,” she said. The global jury of experts was led by Hashim Sarkis, Dean of the School of Architecture & Planning at the Massachusetts Institute of Technology (MIT) in Cambridge, MA, USA. He was previously a member of regional Holcim Awards juries in 2011 and 2018. The jury included Angelo Bucci, Co-Founder, spbr arquitetos and Professor of Building Design, Universidade de São Paulo (Brazil); Bruce Gibbons, Managing Principal, Thornton Tomasetti (USA); Anne Lacaton, Principal, Lacaton & Vassal Architectes (France); and Mun Summ Wong, Co-Founder, WOHA (Singapore). In addition, Maria Atkinson AM, Founding CEO, Green Building Council of Australia; Meisa Batayneh Maani, Founder & Principal Architect, Maisam Architects & Engineers (Jordan); and Brinda Somaya, Principal Architect & Managing Director, Somaya & Kalappa Consultants (India) were members of the jury, representing the Board of the Holcim Foundation. All projects nominated for a Main Category prize in the regional phase of the competition in 2020 were invited to provide an updated project submission for evaluation by the global jury. The authors were requested to include additional information on the carbon footprint and circularity of materials of their project. AC Coordinator Luisa Pastore led a team that examined responses by the project authors to the environmental impact, circularity and lifecycle performance of their global submissions. The Global Holcim Awards jury 2021 (from top left): Brinda Somaya, Hashim Sarkis (Head), Maria Atkinson, Angelo Bucci, Bruce Gibbons, Meisa Batayneh Maani, Marilyne Andersen, Mun Summ Wong, and Anne Lacaton. The Holcim Awards is the world’s most significant competition for sustainable design. It offers a total of USD 2 million in prize money per cycle and foregrounds exemplary approaches to architecture, engineering, urban planning, materials science, construction technology, and related fields. Submissions are evaluated using the five Target Issues for sustainable construction of the Holcim Foundation (page 6). Under the headings of Progress, People, Planet, Prosperity, and Place the Target Issues outline the critical factors on making the environments we build and inhabit truly viable, as the building sector moves towards net-zero emissions and circular material flows.

12 Holcim Awards Gold 2014 Latin America: Articulated Site – Water reservoirs as public park, Medellín, Colombia Global Holcim Awar s Gold 2021

13 New again and again Extending the Cycle in Switzerland Re-use is the order of the day in the face of climate change, increasing resource scarcity, and the gradual shift away from a throwaway mentality. In the Swiss city of Winterthur, an architecture firm shows how high-quality buildings can be constructed primarily using salvaged materials.

14 Holcim Awards Gold 2014 Latin America: Articulated Site – Water reservoirs as public park, Medellín, Colombia Global Holcim Awar s Gold 2021 are full of materials that are still valuable. In less developed countries, such wastefulness cannot be afforded. There, materials are not discarded but re-used again and again. The responsibility therefore lies primarily with the industrialized countries. Although the concept of sustainability is part of good practice in those countries, there are still far too few people who are doing something about the everyday mismanagement of materials and the throwaway mentality. Unlimited growth is impossible on a finite planet, so there is no way around the efficient use of resources, at least not in the long run. These axioms were scientifically substantiated at the latest in 1972 with the report “The Limits to Growth.” Commissioned by the Club of Rome and prepared at the Massachusetts Institute of Technology, this report convincingly demonstrated that radical rethinking is essential. Above all, the depletion of raw materials must be stopped immediately, demanded the scientists – otherwise countless systems are in danger of collapse. “Entirely new approaches are required to redirect society toward goals of equilibrium rather than growth,” states the report. “Such a reorganization will involve a supreme effort of understanding, imagination, and political and moral resolve.” That statement is 50 years old, and still sounds as relevant as if it had been formulated today. “The Limits to Growth” sparked fierce debate around the globe when it was published and gave a huge boost to the then fledgling environmental movement. Objectively considered, the necessary rethinking has not taken place, the “entirely new approaches” have not been implemented. According to the UN International Resource Panel, global resource consumption “Designing with salvaged building materials does not limit creativity” Barbara Buser has since tripled to 90 billion tons per year. It is estimated that this figure will double by 2050. The biggest influence on these impressive figures is the construction industry, which accounts for around 60 percent of global material consumption and over half of global waste. Vast landfills “In Switzerland we’ve always had to make do with what was there” Barbara Buser One of the people taking the topic seriously is Barbara Buser. The Swiss architect, who graduated from the ETH Zurich, was involved for many years in technical collaboration projects in Sudan and Tanzania. “In Africa, I learned that what is waste for us in Switzerland is considered a valuable resource elsewhere,” she says. Back in her home

15 country, she founded the Verein Bauteilbörse Basel (Basel Building Component Exchange) in 1995, a nonprofit company that aims to return as many used but valuable building components as possible back into the service cycle. It is a trading post for finding and selling good building components that are salvaged when a building is demolished. Anyone who is constructing a building can find useful items at this marketplace. In 1998 Barbara Buser founded the architecture firm baubüro Mitte together with Eric Honegger. This gave rise to baubüro in situ, which today employs around 60 people in Basel and Zurich. The firm’s particular strength lies in adaptive re-use and transformation projects. One such project is located in Winterthur, a city of 100,000 near Zurich that was once a bustling industrial hub. With the decline of the secondary sector in Switzerland, vast factory sites became available in Winterthur. Many of the old industrial buildings were converted into cinemas, shopping centers, high-end loft apartments, spacious offices, and so forth. The roughly 50,000-square-meter storage yard directly behind the main train station was abandoned and made available for new uses after machine production stopped there in the 1980s. Initially, interim tenants moved into the various industrial buildings. Then in 2009 the Abendrot Foundation bought the entire site. This pension fund is strongly committed to sustainability. Among other things, it invests the money it manages in real estate that is built and managed with as few pollutants and as little environmental impact as possible. Due to the size and complexity of the site, the Abendrot Foundation appointed a project management team for the development of the former storage yard. Barbara Buser and Eric Honegger and Klara Kläusler are the members of this team. The objective from the beginning was to preserve all the buildings on the site – and when Barbara Buser is involved in a project, one can always

16 Global Holcim Awards Gold 2021 Marc Angst (MA): It takes a lot of ideas, so teamwork is essential. Whenever someone gets stuck, someone else comes up with a promising idea. This kind of work is extremely exciting. Kerstin Müller (KM): For me, one of the big challenges is to properly evaluate the materials, not only their condition but also in terms of sustainability and embodied energy. No one had any experience with this, there is no real precedent project, and technically it’s all quite demanding. Once we have selected a component, we have to collect a lot of information about it so that we can use it appropriately. Unlike with new products, this data is usually not readily available. Barbara Buser (BB): Another challenge is the cost. The foundation fully supported our vision but also demanded that the recycled building cost no more than a new building. Designing and constructing a recycled buildassume that wastefulness will stop and old things will be put to new use. Nothing on the site was completely built anew. The sensitive treatment of the old building fabric has paid off, the conversion of the site is a success story. Space in the buildings is in demand, the tenant mix is balanced, the outdoor spaces are lively. The great care with which the overall project was conducted can be felt everywhere. The buildings have lost none of their industrial charm, yet are fully equipped for contemporary uses. The phrase “tradition plus innovation” is quite apt here: The old walls are home to future-oriented companies and many startups and creative thinkers. Most of the construction work at the storage yard has been completed. One of the later subprojects is the conversion of an old warehouse, Building K.118, including the addition of three floors. The project team pursued a particularly ambitious vision for this building: They wanted to use only materials salvaged from demolished buildings. A recycled building – entirely in the spirit of the Bauteilbörse! Numerous experienced employees of in situ were involved in this project. What is different about constructing a building out of salvaged materials? Pascal Hentschel (PH): The planning process is reversed. Normally, first you do your design and then you specify the materials to build it. But in this case, you first look at what materials are available and put together a material catalog. Using that, your design takes form and develops constantly as the search for components progresses. You have to constantly analyze how to use what’s available. “What is waste for us is considered a valuable resource elsewhere” Barbara Buser “Data is usually not readily available” Kerstin Müller “This kind of work is extremely exciting” Marc Angst

17 ing, however, requires a great deal of labor, which is very costly in our case. The decisive factor is the ratio of material to labor cost. That’s why there is much less waste in Africa, where material is simply much more expensive than labor. In the long term, however, it’s a matter of preserving values. There are also material or workmanship values. I find it disrespectful to simply throw away a window or a door after a depreciation cycle of ten years. And there are also energetic values; the components bind a lot of carbon. Cultural values also matter – and some of them are closely connected to the site. Are you seen as an eccentric if you recycle building components in Switzerland? BB: No. I feel that in Switzerland there is a sense of unease about throwing things away. That probably has to do with the fact that we’re a country without raw materials. We’ve always had to make do with what was there. That’s why quality and innovation are so important in this country. There were hardly any resources, the winter evenings were long – so people did things like tinkering with a new function for a watch, which required little material. Constructing a building from used parts first of all requires research. What is available in the first place? Where are windows, doors, flooring, or structural elements that could be used? In a country like Switzerland, where there is a lot of demolition and reconstruction, used material should theoretically be abundant. But you have to find it and get it. Kerstin Müller says they are “component hunters” who seek value in “urban mines.” If they see that a building is being demolished, they pick up the phone to salvage something, if possible. Because the Swiss apparently do not like to throw away material, it often happens that contractors will seak a component hunter of their own accord to offer material. Ideally, building components are deconstructed and immediately re-used on a different site close by. That would be the ideal solution. “It never works out!” sighs Barbara Buser. It would be different if there was a huge market for used components and the materials could be turned over quickly. Now, however, there is still a danger that one simply fills a warehouse with good things that one can never use – and that just generates costs. Broad rethinking and “entirely new approaches” are needed in order to establish the recycling of salvaged building components on a large scale.  “We pushed ourselves to the limit” Pascal Hentschel “The components stimulate creativity immensely” Benjamin Poignon

18 Global Holcim Awards Gold 2021 PH: In residential buildings, materials are often fastened invisibly, whereas commercial buildings are usually constructed in such a way that the elements can be separated more easily. BB: The big drama is composite materials. There have been phases in recent construction history when people simply didn’t think about the entire life cycle of a building. But I believe that sooner or later it will become the norm to make not only a pollutant concept for a building but also a recycling concept. It must become standard practice to assemble buildings in such a way that they can be taken apart again. Back to H118: The component hunters made a particularly important find on the Lysbüchel site in Basel, where a large retail company was rebuilding its distribution center. The salvaged steel beams of the distribution center became the structure of the H118 expansion. The four floors are accessed by an exterior steel staircase salvaged in Zurich. It was previously part of the Orion office building, as were the granite façade panels that were converted into balcony pavers. Radiators could be brought in from the surrounding area. Aluminum insulated windows and red siding panels from Winterthur and Zurich serve as cladding. Roof elements come from Aarau, solid wood doors from Uster – all nearby places. All in all, around 50 groups of salvaged components were used, including the photovoltaic system installed on the roof. It’s ideal when you can take as much as possible from a single demolition site,” says Marc Angst, “then you don’t have to negotiate as much.” A striking amount of material comes from industrial buildings. Aren’t residential buildings suitable sources for salvaged materials as well?

19 And that means, for example, screwing instead of gluing. Buildings like H118, designed to be taken apart again, can only become standard practice in the long term if the entire industry rethinks material life cycles. But even in the best-case scenario, it may never be possible to construct a building entirely from recycled parts. logistically feasible. At some point, however, it simply no longer makes sense to insist on using salvaged materials because of the cost. For example, if you tried to salvage all the kilometers of cable needed in this building from demolition sites, you would find that the undertaking is simply unaffordable. Even if it would be possible to create a completely recycled building, this doesn’t seem necessary to me. H118 was not a pure learning exercise, it was about showing what can be done with expertise – without breaking the budget or finishing behind schedule. Incidentally, in situ always looked for the lowest-impact “The big drama is composite materials” Barbara Buser What percentage of your recycled building actually consists of salvaged materials? PH: At the beginning, we were aiming for 100 percent – but now we don’t even know how to measure that exactly. In terms of visible surfaces, we are certainly close to 100 percent, but in terms of mass tonnage, we may achieve only 50 percent because the new components, like most of the concrete decks, are very heavy. According to our calculations, the carbon savings are about 60 percent. I would say we have certainly saved 500 tons of carbon emissions through our approach. We pushed ourselves to the limit, we tried to realize everything that was

20 solutions, even with new materials. Natural materials such as wood, straw, and clay were used as the primary new building materials. You said that the design process is reversed in a project like this: The architects don’t develop an idea and then specify the materials but rather select from the available materials and develop the idea based on that. Doesn’t that restrict your creativity? Benjamin Poignon: Not at all. The components stimulate creativity immensely. You simply let yourself be inspired by what you have available. BB: In a university course we once presented a material library to 20 students and gave them the task of designing a project based on that. The result was 20 totally different and exciting projects. No, designing with salvaged building materials does not limit creativity. Nevertheless, there must be limits: If you want to have a façade with 200 identical windows, this may not be feasible. BB: Granted, you probably won’t be able to find 200 identical windows, but you don’t need to! We will not be able to save the world if we continue to build on the same scale as before. It cannot be the goal to realize such monotonous superstructures. At the latest when you enter one of the 12 rental units in H118, you sense what Barbara Buser’s last statement means. The spacious rooms on the four floors are bathed with light and have modern lines – the material palette exudes something venerable. There is history in every visible part. And each part Global Holcim Awards Gold 2021 continues this history into the future. You sense the great appreciation of the materials utilized in the building. In situ applied an extraordinary amount of understanding, imagination, and political and moral resolve in this project – as was called for 50 years ago!

21 Project appraisal by the Global Holcim Awards jury Quality towards which the building industry should aim The Global Holcim Awards jury highly commended this project for the disruptive construction methodology it proposes to achieve carbon neutral buildings and enable circular economy models in the field of design and construction. Energy savings here are achieved on three levels: demolition is minimized in favor of adding new elements to refurbish an existing fabric; construction material mainly consist of re-used components; when new materials are needed, the project opts for low carbon or carbon negative ones. In contexts like Switzerland where demolition is still a rather frequent practice that precedes new construction, this project shows how much potential exists – and is lost – in buildings that are torn down, to the point that dismantled elements are re-used as brand-new components for new construction. The ability of the building to be easily assembled and disassembled to allow for future modifications and re-use was also highly commended by the jury and recognized as a quality towards which the building industry should increasingly aim. Initial project submission page 52

22 Holcim Awards Gold 2014 Latin America: Articulated Site – Water reservoirs as public park, Medellín, Colombia Global Holcim Awar s Silver 2021 Back to nature Wetland Vitality in Colombia

23 Wetlands are among the most important ecosystems in the world – but they are endangered in many places. In the Colombian capital Bogotá, a team of architects is showing how damaged wetlands can be repaired and protected for the future.

24 Holcim Awards Gold 2014 Latin America: Articulated Site – Water reservoirs as public park, Medellín, Colombia Global Holcim Awar s Silver 2021 A further environmental problem is water pollution. There are over 200 bodies of water in the Bogotá metropolitan region. Particularly significant is the Bogotá River, which flows through the west of the city. It is considered one of the most polluted rivers in South America, as it receives the trash and sewage from millions of residents as well as industrial waste from southern Bogotá. The mechanical sewage treatment plant is completely overwhelmed. Various sections of the river are classified as dead, without any oxygen. The catchment area of the river includes various wetlands. These have strongly shaped the area and play an important role for the entire region north of the Andes. Wetlands are also important for the planet as a whole. They probably bind about ten percent of all carbon deposits. Wetlands regulate water cycles, prevent flooding, retain sediments and nutrients, and act as water reservoirs. The historic city of Bogotá enjoys an exceptionally attractive location. The combination of high altitude and proximity to the equator results in a mild and pleasant climate all year round. Rain falls regularly, water flows abundantly, and the altitude range allows the cultivation of a wide variety of crops. The indigenous Muiscas people, who settled here thousands of years ago, called their settlement Bacatá, meaning “high field.” In 1538, the Spanish conquistador Gonzalo Jiménez de Quesada founded the city anew under the less original name Santa Fe. But the original name managed to stick and eventually became the official city name: Bogotá. Today, more than ten million people live here; hardly any other city in South America is growing faster. The urban population explosion has had serious consequences. There is not enough work for the newcomers, so poverty is prevalent, which in turn leads to a high crime rate. The city’s infrastructure is massively overburdened. The streets are notoriously congested, and smog is a constant problem. Because the city is located in a geographic basin, a cloud of haze from decades of misguided transportation policy hangs above it. “All in all, the design of the park was a very organic process” Sebastián Mejia “Nature just takes time” Edgar Mazo

25 They improve air quality, act as dust retainers, regulate temperatures, and produce oxygen. Another function concerns flora and fauna, as wetlands provide habitat for countless endemic and migratory species. In a densely developed city like Bogotá, the social importance of such open spaces is also not to be underestimated. Wetlands serve as recreational areas and create territorial and cultural identity. Bogotá’s population growth has led to the development and destruction of most of these ecologically and culturally significant resources. It is estimated that of the 150,000 hectares of wetlands that existed in and around the city in 1940, only 1,500 hectares remain today – just one percent. They are spread over 15 different sites. The 152 hectare Jaboque wetland in the west of the city has been preserved to some extent. It is located near El Dorado airport and borders on the polluted Bogotá River. The vegetation of the ecosystem is impoverished. Parts of the wetland were illegally settled by displaced people. The tree population was reduced to a few acacia and eucalyptus trees. Since the 1980s at the latest, this wetland has also been used as a garbage dump, and sewage from surrounding districts has flowed into Jaboque. UNESCO’s Ramsar Convention lists the world’s most important wetlands, currently around 2,400 in 171 countries. Jaboque has been on the list since 2018. Incidentally, the name of the territory is derived from the Muisca language and means “land of plenty.” This wetland, which has been so badly damaged, is currently being transformed into a huge nature park of 5.5 kilometers in length. The Medellín-based architecture firm Connatural is in charge of the project. The firm was founded in 2011 by the architects Edgar Mazo and Sebastián Mejía. In all its projects, the firm strives to achieve a dialog between art, architecture, and landscape. Edgar Mazo is a graduate of the National University of Colombia. He is an intern professor at the Pontifical Catholic University of Chile and guest professor at Escola da Cidade in São Paulo. He gave lectures at the Harvard Graduate School of Design, Arizona State University, and other universities. Sebastián Mejía is also a graduate of the National University of Colombia. He was a professor “People began to recognize the value of the wetlands” Sebastián Mejia

26 Holcim Awards Gold 2014 Latin America: Articulated Site – Water reservoirs as public park, Medellín, Colombia Global Holcim Awar s Silver 2021 the police could not guarantee safety there. But people lived beyond the fence – low-income people and victims of the armed conflict. Trash and sewage, illegal construction, modifications of the riparian buffer zone and other interventions acutely threatened the ecosystem of the wetland. SM: But people began to recognize the value of the wetlands – and to protect the land. Around Jaboque, there are numerous neighborhoods that lack open space. A strong citizen’s movement emerged there to preserve the wetland. Various NGOs and government agencies are also involved, as are those who have settled in the wetland; for them, Jaboque is their habitat, which they want to preserve. at the Pontifical Bolivarian University and a guest professor at the Harvard Graduate School of Design, Torcuatto di tela in Argentina and the Pontifical Catholic University of Chile. He was also a lecturer at Querétaro Congreso de Arquitectura Natural 3. Most of Bogotá’s wetlands are gone – why has Jaboque survived? Sebastián Mejía (SM): Although urban growth has been enormous, there were so many wetlands here that not everything was immediately destroyed. Jaboque was the epicenter of the Muisca culture, part of the Chibcha language family. The Muiscas, who lived here from 500 to 1500, excelled in goldsmithing and the engineering of irrigation systems. They are a part of our history that we are proud of. Remnants of their culture remain in the wetlands, which probably helped protect Jaboque. Does the airport, located near the wetlands, also play a role? Edgar Mazo (EM): The wetlands were partly drained for the airport, which caused damage. On the other hand, tall buildings cannot be erected near the airport, so no heavy development could take place here. How has the area been used so far? EM: It was fenced off for a long time and closed to the public. Entering Jaboque was dangerous because the area is so large that

27 How did the current project come about? EM: The municipal government saw that something had to be done to save the wetland over the long term. In 2016, Jaboque became part of Bogotá’s development plan “Bogotá Mejor Para Todos.” The idea was to design a large park there. The city invited a specific group of professionals to submit a portfolio. We were awarded the commission because we do constant research related to water bodies and hydraulic basins as well as projects related to landscape and ecological restoration. One of our key references is a large project to rehabilitate the Medellin River. SM: We are architects, but we have experience with landscape projects with an environmental approach and a strong network of specialized professionals. On this project we are working with two landscape architects, two biologists, and a civil engineer who specializes in bio-construction. At first, Connatural and the authorities had differing ideas about what the future park should look like. The city wanted to build numerous pedestrian and bicycle paths and a lot of other general infrastructure, but that would have ruined the ecosystem. The architects spoke to the officials and also solicited public input. The tenor was clear: The people wanted a park that was as natural as possible and including as little construction as possible. How was the participation of residents of the surrounding neighborhoods? EM: At first it was really difficult to connect with them because a lot of people don’t trust the government – and we were hired by the government. That’s why we began collaborating with a social worker, an anthropologist, and we approached various community leaders. This contact allowed us to visit schools and other institutions and explain our project to the people. We passed on their feedback to the authorities. Did the people offer any new ideas? SM: Yes. Some of them were in tune with our ideas, others were at variance with them. One wish, for example, was to have community gardens for traditional plants. Our master plan takes some of these ideas into account, including the community gardens for residents of the nearby neighborhoods. All in all, the design of the park was a very organic process. The project is comprehensive and complex. If you look at the usual before-and-after pictures of the project, you will understand why it took so long for someone to take action here: The condition of the polluted vast wetland was so bad that people immediately

28 Holcim Awards Gold 2014 Latin America: Articulated Site – Water reservoirs as public park, Medellín, Colombia Global Holcim Awar s Silver 2021 thereby ensure that the wetlands will not be overused. “Amphibious trails” include bridges over the water and are particularly attractive. Permanent recreation zones and “environmental classrooms” are also being set up because education in nature topics is an important part of the project. Finally, the architects also had to design a few buildings, such as entrance buildings, restrooms, and observation decks for bird watchers. It is extremely impressive to see the number of levels on which interventions are taking place, how many detailed measures have been worked out, and how sensitively Jaboque is being handled. It is obvious that Connatural’s team has made every effort to achieve the optimum. Out of the entire program, what do you consider to be the most important measures? EM: There are so many issues that are important. The measures to reconstruct and revitalize the ecosystem, the protection and strengthening of what is there, and our collaboration with the locals are three of the main ones. SM: It was certainly crucial that we eliminated all systems that discharged wastewater into the wetlands. It was also important that we moved ground back so that water capitulated rather than even starting to roll up their sleeves. The first goal is to restore the original ecosystem through conservation, recovery, and strengthening. Architects and experts analyzed together which plants are endemic, which are non-endemic, which are good or bad for the ecosystem, and above all, which plants are missing. Today, plants that were once native here and have disappeared are being returned to the wetland. Invasive plants that are harmful to the ecosystem are being removed. It’s a very lengthy process, and the Bogotá Botanical Garden is helping with it. Every day, people are working to return the ecosystem to a healthy state. Ultimately, 121,000 square meters are to be replanted. Among the other measures, the links between the water bodies are being restored to allow water exchange, destroyed riparian areas are being repaired, and trash is being removed. Archaeological artifacts from the Muisca era will be identified and presented. Another key element of the project involves development. Firstly, inappropriate structures, such as those built illegally on the banks of the water bodies, are being removed. And secondly, various trails made of permeable concrete are being built, mainly along the edge of the wetland. The trails are narrow in order to limit capacity and levels could recuperate, even if the authorities complained that this was costly. This provided flood control and it benefits biodiversity. What were the greatest challenges? SM: The greatest challenge was to establish a balanced relationship between the communities related to the Jaboque wetland and the different technical teams, this strengthened the project decisions. It’s a project about giving something back – back to the wetlands and back to the people who live around them. What is the status of the project? EM: Some sections of the park are already open, others are still under construction. About 75% of the construction work had been completed by 2021. But it will take another five to ten years before the park is in the condition we are aiming for. Nature just takes time. It’s nice that we receive so much positive feedback. People are enthusiastic! “Establish a balanced relationship between communities” Sebastián Mejia