In this episode of Buildings 2.0, Jose speaks with Charu Chaudhry, Associate Principal at Thornton Tomasetti, to explore the fascinating world of historical building preservation. Charu shares her journey from working on 10th century Buddhist monasteries in India to tackling 18th century rowhouses.
Charu offers her insights into balancing historical preservation with modern needs, leveraging technology like scanning for accurate data collection, and redefining sustainability through durability and long-term building performance. Charu’s expert perspective provides a fresh perspective on how to honor the past while embracing the future in building design.
Topics discussed:
- How to maintain the integrity of historical buildings while incorporating contemporary requirements and innovations.
- Leveraging modern tools like scanning and data collection to accurately analyze and preserve historical structures.
- Redefining sustainability by focusing on the long-term performance and durability of building materials and structures.
- Using analytics and a deep understanding of materials to enhance the performance and longevity of historical buildings.
- Discussing specific projects, such as 18th-century rowhouses, and the unique challenges and solutions involved.
- Conducting hydrothermal studies to understand the performance of building envelopes and improve their preservation.
- Methods to analyze stress concentrations in historical buildings and how this informs preservation strategies.
- The importance of working with various organizations and stakeholders to achieve successful preservation outcomes.
I'd say I'm an architect and architectural conservator and that kind of sums me up in many ways on how I approach, how I feel excited about building environment in general. I'm very much an architecture geek, but I'm like a science nerd. I'm looking at building materials at a very microscopic level when I'm looking at buildings. Welcome to Buildings 2.0, where we dive deep into the technology, trends, and visionaries reshaping the very structures we work in. Here's your host, Jose Cruz Jr., CEO of Integrated Projects. Hey, everyone, and thanks for listening to another episode of Buildings 2.0. Today, I'm speaking with Chardru, Chardru, Associate Principal at Thorne Thomasady. Chardru, thanks for chatting with me today. Absolutely. My pleasure. Share it with us your background. So before you were an associate principal at Thorne Thomasady, you were just a young girl grown up appreciating the built environment. What was that like? It was wonderful. I graduated as an architect in India. When I finished college, I was working in regular building industry. I did not have the background of historic preservation or existing buildings in general. That was not a part of my education at that point. I got involved into working on 10th century Buddhist monasteries in India just right after school. When a professor from school came to me and said, "Well, we are embarking on the study. It's a research project. Would you be interested in joining the team?" And without thinking a second block, I said, "Yes, I did not know where it was on the map." And I said, "Well, 10th century buildings, that's exciting." I just left the world of reinforced concrete and went to this journey of understanding Adobe, some of the most fragile buildings and constructions and materials, braving the world of climate change up in the mountains of India, and holding some of these communities, indigenous communities that carry a cultural significance for us. And my time there was intermittent for, I kept going back and forth for five years there. I worked on three monasteries dating back from 10th to 12th centuries. And I did a lot of advocacy work in revenue generation for the work that was supposed to be done. I got involved with various organizations as part of my work there. And after that, I got some internships with Icomos, British Council of India and National Park Service in the U.S. here. And as part of my internships, I was an exchange student. I went back and forth to different countries and then learned from established people in this industry, understanding material science, understanding how buildings behave in different climates, different situations. And after that, I went back to school to get my master's in architectural conservation. So I'd say I'm an architect and architectural conservator and that kind of sums me up in many ways on how I approach, how I feel excited about built environment in general. I'm very much in architecture geek, but I'm like a science nerd. I'm looking at building materials at a very microscopic level when I'm looking at buildings. In your years of experience, do certain principles or tactics stand out? Perhaps to use your 10th century Montessori example. Are there things builders did back hundreds of years ago that stand test of time? How did they think about materials and putting buildings together that perhaps has evolved over time, and maybe we could actually take a pointer or two from back in the days? Right. A lot of things have changed in terms of material science, construction technology. Older buildings presented simpler materials with more challenging issues of durability. And frankly, the buildings I saw very early on in those Adobe monasteries were that the material that you can kind of easily discredit as fragile and undurable if prepared correctly or if used correctly in a building system can really last thousands of years. What we see now is that there is a lot more complexity into material science into making building materials has gotten more sophisticated building technologies have gotten more sophisticated. It's simpler building like an Adobe which wasn't supposed to receive water. It was cold. They were meant for cold and dry climates. However, since almost five decades or so, the climate in that region has changed dramatically in receiving periodic rainfalls. So even when a building like Adobe which was not meant to receive rainfall has been enduring rainfall for more than five decades tells you that materials often exceed the expectation when they are maintained properly with small amount of upkeep, the lifespan can be extended significantly and the lifespan is not an end of destruction of a building is not as finite as we kind of think now for now the buildings are made for let's say hundred years or fifty years. There is a lifespan tagged to it before that it wasn't that thought when we built we built for life and I think that has negatively shifted in a way that we are tagging like a lifespan to everything in terms of I would say there are a lot of technologies that have improved in terms of science I follow that quite regularly the science of new building materials the science of conservation of existing buildings that is very exciting for me. Some kind of materials I don't feel that excited about because to me I'm a natural person. I like to see materials that are close to natural elements in the world that I can identify when materials are too synthetic I feel skeptical about that I feel skeptical about giving them a durability factor if you say so. Are there active or previous projects that stand out to you as an example of success? I imagine when you approach a project where historical and there is some significance to it I'd imagine you have to balance between some of the modern needs and requirements together with how do you preserve what frameworks do you use to think about this the design process and how do you balance between the two? So it's the core of my existence this question is the core of my existence it's something we battle on project to project bases so my work is focused on renovations reuse and restoration of existing buildings right whether they are being adaptively reused for a new purpose or they are being enhanced for their comfort levels or performance levels or just the buildings are falling apart in have to be preserved so there is a lot that goes into that thinking besides just well let's fix the building we look very carefully in analyzing so analytics building analytics and materials understanding from the core of any decisions on how to improve or enhance their performance for the next X many years so looking at the surface it looks like it's an ocean to traverse because it's like where do I begin I have this building how do I go about it but actually I like to break this down into droplets of water because otherwise it is an inundating adventure to embark upon so I look at this as assemblies one of the projects that I cannot say the name of but it's a big institutional building in very early modernist building it stands on you know unique kind of a plaza looking at the building which was kind of a modern building kind of appreciation space the modernist movement was if you look at a lot of modernist buildings they stand on a plaza which was the appreciation place so we were looking at this plaza overlooking this modern historic building and there were issues of accessibility and the fact that the plaza was leaking and deteriorated and just falling apart it was lined with historic materials and the way this slab and the construction of that assembly was there's not enough space to kind of play with the levels to do thermal upgrades like put insulation or another kind of system which gives a more of redundancy for moisture management within the system so those are the kind of issues that are very exciting for me because I love challenges so looking at these archaic assemblies and seeing how can I intervene what can I possibly do to juxtapose these new elements that I want to put in enhance you know upgrade this for accessibility have good ramps and slopes upgrade this for material durability make it watertight and also make it pleasing for people to walk around it so all these are great questions and I think in terms of plaza the issues are really like thermal upgrades so there are ways to creating these vapor barrier lines within existing assemblies which does not interfere with the top surfaceing materials in other words go under the assembly because we can play in the interior space below in that case that really worked out for us besides we had to do some minimal disruptions around the site to include a more updated waterproofing system so I think thinking creatively in how to inject those new materials into the assembly without disrupting too much on the surface of the assembly is how we think about older buildings don't give us a lot of redundancy in their systems they're very honest they're very open so there is not too much too many layers to it which is what I like that honesty of expression so working through these issues for example another building we were working on and it's a 18th century row house where some of the buildings on the side were demolished to create a new tower for residential you know financial district in Manhattan where there are these pressures of growth so the older kind of smaller buildings got demolished to create a residential tower and while the construction activity was happening even though this building was temporary shore and protected the construction activity induced so much stress in the building that the walls started playing open and the ground started subsiding so here you see a 18th century wonderful building really fighting for its life and to me that was a very meaningful pursuit in attacking that issue in bite-sized pieces first was it's almost like being in the ER and stabilizing the patient like just don't fall apart we'll restore you later just right now we need to keep you like holding on keep breathing so that's what we did we attacked it with some really emergency temporary shoring so that the walls are not completely falling apart and once we got a handle on how much vibrations are we allowing this structure to endure once we brought that down to a sustainable level we delved deeply into what we can do about these walls that have suffered a lot so as you know it's old brick wall there's not much to it except brick and mortar so we kind of found ways to do injection grouting there with compatible materials that induce that homogeneity back into the structure so it can endure the principles of all the buildings are actually really simple it's homogeneity in no voids right the voids are giving places for water to stay so just eliminating those simple things enhance the durability of that wall so that's what we did there and once we stabilized the structure control the vibration stabilize the walls then we started restoring some of the components windows cornices groups that happened later but before we kind of tackled some of the very emergency issues so these pursuits are meaningful in a way because now I walk by that building it's a school occupied by a school construction authority I see little kids walking in and out of the building in that I look at it and I said these little souls have no idea this building was falling apart but I was there so these are some of the meaningful aspects of my life well I'm fascinated because the way that you speak about it it's almost surgical in nature right where there's a component of just understanding or just diagnosing like what is there and then there's another component of determining what should we do talk to me about the mechanics a little bit like when entering into a building one of the things that certainly I in my team has learned is it's actually really difficult to get an accurate set of drawings for any existing building certainly let alone a for example a 10th century monastery what are the parts pieces equipment ingredients dots that you have to connect that even properly diagnosed what is going on how do you start that process yeah right I mean you hit the nail on the head and this is kind of a bane of my existence where if we are starting on a new project and there are no drawings to begin with it's tough I wouldn't say that it's like you know we can roll with it because to understand buildings are a lot materials but also it's engineering it's mechanics of it so understanding how the spaces are connected to each other how the sections are what the levels are this is really important components to diagnose what's going on with the building in terms of you know how forces are moving how stresses are concentrated in certain components or not so if there is nothing I think like there are traditional ways to kind of start measuring buildings and start making drawings but I've grown fond of doing laser scans of buildings now these are very efficient we can do interior scans exterior scans I also like using drone imagery collected in it's so nice to see that these images capture a great level of detail and the images can be stitched together in some kind of an orthomosaic and that presents a building it depends what we are working on because for some buildings the work is on the exterior so understanding the exterior facade in detail is very important so having those kind of imagery is really interesting because then you can scale things you can understand things you can really go into great detail to see the condition of components and how components are connected I have grown fond of the ways to scan and the ways to get information out of buildings if nothing is there to begin with do you find in the design process so once you've accurately scanned or captured the information or there's specific tools or processes in the design process you find helps kind of better frame how to approach the challenge I imagine once you start you've got a host of different considerations from how are we doing right by the building and it's original intention but also some of the emerging challenges like being sustainability some of the new regulations going into place and what are the different tools and processes that you've kind of taken the design process where you're stitching it together once you kind of understand okay here's what is now let's determine what we should do about it yeah so it's a very interesting question because there are lots of tools to kind of do data collection and understand what do we have at hand but the analytics right now is still very kind of oriented it's very much there are small tools like Comcheck I'm just off the top of my head where you just give a quick analysis of what are the requirements per codes and then take it from there I think after we established these parameters using Comcheck there's one analytical tool that I like I have really found success with is if there are thermal upgrades desired in the building with archaic assemblies I would say that one tool we often use is understanding the dew point in the mason grease and doing this kind of hydro thermal studies of existing envelopes it's a lot about how the envelope is performing so while we do certain upgrades thermal upgrades to the walls the roofs are much easily understood because it's about stopping the vapor so it's easier without the need of complex modeling it's easier and more established however when there are walls in question there's a lot of something that we need to think about is what is the state of distress of the wall at present and when I upgraded for thermal value is it creating more distress in terms of vapor drive and is it going to create mold and other issues in the building more damp in the building or am I solving that issue so one is that so hydro thermal studies are really important for it there are other issues also I would say you know depending on the kind of issues you are you're encountering I'm also something I've used is finite elemental analysis in our analysis to understand stress concentrations this is especially if structures are being modified for something else for example in another project we're working on when buildings evolve over time there are new components that are added some components are removed and there's this whole archaeology that we are undigging basically to understand what are the bare bones what is the bare structure you know what is the impact of those decisions when we remove something it's through finite elemental analysis we can understand those stress concentrations that the building is enduring I'm just thinking out loud so another thing I learned recently was this is more of an issue in modern buildings but also certainly any building is the issue of air leakage not necessarily just water leakage sometimes the buildings perform well underwater however air being very fine and easy to move through building inconsistencies can find its way in many ways and manifest sometimes as humidity as you know warping of the floor panels or wall finishes disintegrating or something or many ways this can or just building draft drafty building so this was a like a big post-modern tower in metamanhattan in looking through air leakage issues we found that some of the simple analytics of understanding air movement through building can give us great deal of information a simple camera like infrared camera can talk volumes about where the inconsistencies are within the building envelope so I'm a fan of using these simple tools and techniques to get a handle on bigger issues and kind of take it from there there are more complex analytical tools like computational fluid dynamics and other kind of modeling softwares which also have a very unique place in our industry and I'm mesmerized now that we have these tools and we use these tools we gain so much more understanding of how this organism is behaving with the outside environment where is it that I want to keep the outside environment as out and I want to have a controlled interaction with the outside environment I think those are the four kind of values but how to assess that I do fall back on some of these modeling softwares I would however caution to whoever is using these softwares modeling it's fine to use it but defining your problem first if we are not defining that problem we are just kind of swimming in the ocean of data not knowing where we have to go with it so I think defining that problem which is just really a result of your interaction with the building understanding of the building diagnostics and pathology in your core values on what we are trying to achieve once that framework is defined modeling analytics come later and one of the shared missions that many real estate professionals around the table are thinking about right now is this what seems to be an insurmountable challenge of decarbonizing our buildings I have a question in two parts one is help me demystify if you double clicked into what does it mean to decarbonize buildings if you help me double click into that and then the follow up is do you find that that modern buildings as opposed to older buildings have kind of a different ratio by which they're contributing co2 and the atmosphere so let me demystify carbon in our buildings wow let's say insightful question and I'm glad that we are talking about this decarbonization in its what I understand in its basic sense is that let's not waste energy from our buildings stop so in other words try to have our carbon footprint in the ways we expand energy on buildings as minimal as possible now we expand energy on our buildings in two ways I think one the industry likes to talk about it as embodied energy or embodied carbon operational energy operational carbon and they're great two buckets operational energy is very well understood it's like the kind of appliances we use the kind of HVAC and other mechanisms hot water things related about with building services the other is the embodied carbon where how the building envelope is performing and I think it's connected because if it's a leaky building it's going to have a higher operational carbon if we just start fixing the buildings with incompatible unsynthetic methods it raises that embodied carbon threshold bucket in some ways because of you know here's where the contrast of sustainability lies because sometimes it looks like something that's readily available or something that has a lower you know some material that is let's say environmentally more sensitive might not be compatible with this building but it's used in that building for repair but it didn't enhance the durability of the building hence the building carbon value declined so in that regard how do we maintain our buildings to provide these machines well oiled machines which are using these operational carbon in a manner that we would like it to be used there's no wastage I think that is the interaction between the two that are industries not really talking that much at right now so decarbonization to me is a good marriage between the embodied carbon and the operational carbon and in that sense one needs to work very well with the other all the buildings more vernacular in nature very empirical ways of building the buildings there was less of values in that sense we're still understanding those kind of values on how to calculate the embodied carbon the industry has not caught up because it's complicated to calculate a carbon on an existing building that has been in service for 100 years or 50 in some of those materials like in the 60s and the 70s the much older buildings were created with much natural materials so even if we don't have values we have kind of understanding of those materials and the fact that the end of life destruction for those natural materials breaks stone you know cements is far in advance but some of the more synthetic materials that kind of came into existence later on have a shorter lifespan in that regard and injecting more kind of durability into that is complicated the buildings that we make now are easier to calculate in terms of giving them values for embodied carbon they can be designed for circularity or they can be designed for sustainability goals right the values that we provide or the rating system that we provide for lead or something with older buildings since they did not exist with those values they did not have that purpose or they were not fighting the same battles that we are fighting now it's not a real apples to apples comparison i think a good underlying principle for an older building is to in my opinion and maybe the others might find an urge to disagree with me and i would invite disagreement is that for an older building when there is this lack of calculation i'm not a big fan of calculating or putting numbers to everything because it think that's in existence putting a number to that is insufficient way of understanding that building i think it's sufficient good way of understanding an older building is to understand their materials completely understand their assemblies completely and find the ways to make it durable instead of quote unquote sustainable an existing building already is a sustainable endeavor this endeavor right now is to make it durable so that it can endure another hundred years of its life i think that is a fundamental shift in the principle that i think is missing in our conversation for an existing building i love the way you frame it i think that's perhaps one of the first times i've heard a specific angle perspective on what sustainability is i even dating back to my own college experience in architecture school at this point everyone has grown up studying and designing and working in a field where sustainability is is a given but oftentimes i find that the word almost kind of dilutes in its nature just because i guess some of the different ways to interpret this sometimes folks just kind of devolve it's just kind of satisfying the certification or checklist of some sort but thinking about it is almost like the durability of a building like how long will it last and then by definition it's sustainable that is a fascinating framework i want to add something strange to this is when i started hearing about oh we have to make this building with these sustainability goals and i used to think that well do you mean that there are buildings we should be constructing without the goals i mean is there a different set of thinking principle that should even be allowed to exist because i think this really should be clocked work for us in like our regular thinking that there's no sustainable thinking that this should all be one thinking however maybe we forgot as our industry forgot that there were these principles that we were to design for and i think sometimes we forget it becomes a checklist of sorts and not really thinking of sorts and that's the part i don't kind of like but the fact that now it's you know regulations are taking place i think it's all steps in the right direction i feel really grateful that i'm here at this point in my career seeing all these tides of change happening and i'm there and you know there is my voice that can add something to the discussion so it's a great time to be thinking about these things because i think we are standing at that inflection moment in ways because this is where we kind of set the tone for the next hundred years i often like finish with a question with all of the emerging technologies all of the emerging regulations much has evolved over the years the decades hundreds of years building buildings but in your case you have a unique perspective that you're often looking at really really old buildings i'm curious do you find that in five or ten years we have no idea what kind of technology we're going to be looking at or considering as part of the workflow but in five or ten years or in twenty years what is likely not going to change about our buildings i would start with what's not going to change is that the AI use of artificial intelligence is not going to be less it's only going to be more involved not only for basic data collection but analytics and i'm excited about that frankly what's also not going to change our basic design principles basic engineering principles and basic understanding of materials and assemblies diagnostics so i think what i would like to see more in the things that are not going to change is more involvement of science in our discussions because at the end of the world what we do is built world built world is composed of materials with specific chemistries and chemistries can only be either compatible or incompatible in the settings that they are supposed to exist or they are meant to exist i would like to see more of that in the things that are not going to change in the coming few years many years amazing part of this is a really fun conversation thanks again for joining building sequar now yeah absolutely i had a lot of fun
