Loading

Alison's New App is now available on iOS and Android! Download Now

Study Reminders
Support
Text Version

Set your study reminders

We will email you at these times to remind you to study.
  • Monday

    -

    7am

    +

    Tuesday

    -

    7am

    +

    Wednesday

    -

    7am

    +

    Thursday

    -

    7am

    +

    Friday

    -

    7am

    +

    Saturday

    -

    7am

    +

    Sunday

    -

    7am

    +

Sustainable ArchitectureProf. Avlokita AgrawalDepartment of Architecture and PlanningIndian Institute of Technology, RoorkeeLecture – 13Indicators and Terminologies in Sustainable ArchitectureGood morning. Welcome back to the new lecture on Sustainable Architecture. I amDoctor Avlokita Agrawal, assistant professor at Department of Architecture andPlanning, IIT, Roorkee.In today’s lecture we will be looking at the different terminologies and their definitions.The terminologies, which are used in some way or the other for defining andunderstanding sustainable architecture or green buildings. So, these terminologies arespecific to buildings and built environment.(Refer Slide Time: 01:01)The first and foremost terminology which is very commonly used in our discussionsaround sustainable buildings is carbon footprint. Now carbon footprint is the totalamount of carbon dioxide emissions which have the potential of global warming which isaveraged over 100 years.So, what we implied by that is that if there is any process or manufacturing of a productor construction process or any other activity the total amount of emissions which are taking place during that process will be converted to the equivalent carbon dioxide fortheir global warming potential.For example, carbon dioxide is taken as a base which has a unit 1 global warmingpotential averaged over 100 years. However, if we look at methane CH 4, it has a GWPpotential of 23, so 1 molecule, 1 unit of methane emitted is equivalent to 23 units ofcarbon dioxide emitted. So, 1 methane is equivalent to 23 CO 2 emitted.If you look at nitrous oxide N 2 O it has 296 CO 2 equivalents. For HFC and for HFC 23and HFC 134a it has a much higher potential which is 12000 times the carbon dioxideand the sulfur fluorides they have even higher potential of 22000 times the carbondioxide equivalent. Now, what we are trying to look at here is when we are constructingour buildings, we have to be aware of the different processes that go in it the differentmaterials which are going in it and the associated carbon emissions.For example, let us take any activity for that matter. For any sustainable building weadvocate that the materials be procured locally. Now, say stone, which has a very lowenergy which is embodied in it. We will come to embodied energy, but very lowembodied energy content.So, for example, the locally available material. So, all sustainable buildings advocate theuse of locally available materials for example, stone. Stone is a material which is verylow on embodied energy. However, where is this stone being procured from? Forexample, I might have available stone which is locally available, while I might bewanting to use some exotic variety of stone which is to be fetched from a far of distance.Now, to procure the same to procure the stone from a far of place the stone needs to betransported. The emissions which are taking place in all that transportation will becounted towards the carbon footprint of that material when we are talking about thebuilding. The others for example, the HFCs and CFCs, now these are used in the airconditioning systems.So, there are direct emissions and there are also indirect emissions. For example, theamount of electricity that we are using. Now, there is no direct emission which is takingplace it might seem to be a very clean energy source. However, at the point where theelectricity is being produced for example, if it is being produced using thermal power plant where coal is being burnt, coal is being used as a fuel or gas or other forms ofhydrocarbons are being used as a fuel there the amount of carbon dioxide equivalentwhich is emitted is the is counting towards the carbon footprint.For example, if we are using cement. Now, cement has very high carbon footprint simplybecause not just cement, but any other material which is produced at very hightemperatures, so that causes the nitrogen oxides to form in the atmosphere. And there, wehave already seen that it is 300 approximately; 300 times the global warming potential ascarbon dioxide. So, we have to understand what each material amounts to how muchglobal warming potential does each material have in comparison to carbon dioxide andhigher this number higher is the carbon footprint.(Refer Slide Time: 06:02)If we look at this data from IEA, it is very clearly seen that as we are progressing thedirect emissions from buildings are remaining almost constant, but it is the indirectemissions which is what we just talked about. For example, the electricity which isgenerated elsewhere not at the building side. So, those indirect emissions are increasingevery day as the lifestyle is changing as the type of buildings are changing as we moreand more buildings are becoming air condition. So, these indirect emissions areincreasing. (Refer Slide Time: 06:37)The same is seen here, but depending upon our strategy what kind of strategy do weadopt, what kind of way forward do we adopt, we can limit these carbon dioxideemissions, carbon footprint to bring it down or to retain at the same level dependingupon what are the different alternative courses we take.(Refer Slide Time: 07:01)If we look at this footprint calculator. (Refer Slide Time: 07:13)So, some very interesting footprint calculators are available online and we can get toknow our own footprint, but this is ecological footprint. This is not carbon footprint, butit takes into account the carbon emissions largely.(Refer Slide Time: 07:42)If you follow this website and you calculate. So, it gives us what is our footprint basedupon the lifestyle let we choose, whether we eat meat products or only vegetarian diet. (Refer Slide Time: 07:58)(Refer Slide Time: 08:00)From where is the food procured to the kind of housing we live in, to the kind of housewe live in. (Refer Slide Time: 08:07)And are the materials which we are using.(Refer Slide Time: 08:12)The per capita space that is being consumed and also the electricity consumption insidethe home. (Refer Slide Time: 08:20)The kind of appliances we are using.(Refer Slide Time: 08:24)The type of electricity which is being used inside the home whether it is renewable orfrom non-renewable sources. (Refer Slide Time: 08:30)The type of waste we generate and the amount of waste we recycle.(Refer Slide Time: 08:36)The kind of transportation mode we use cars, scooter, bicycle. (Refer Slide Time: 08:46)(Refer Slide Time: 08:50)And the efficiency of car that we drive. (Refer Slide Time: 08:55)Whether we carpool or not, or whether we use public transportation and the majorcomponent is whether we fly, whether we use air transport in each year.(Refer Slide Time: 08:57)And together it gives how much of the resource is consumed if we go on living the sameway as we are doing. (Refer Slide Time: 09:05)So, I have not changed much, but we can see that the overshoot day which is anotherconcept which we have discussed previously that we require around 2.7 earths ifeveryone on the earth lives like the way we do. And we can reduce our carbon footprintif we consciously try to do that.(Refer Slide Time: 09:41)The next terminology is environmental footprint. Now, environmental footprint talksabout the impact determined by the amount of depletable raw materials and nonrenewable resources consumed to make the products. Here since we are talking about buildings, we will be talking about the resources which are consumed to make thesebuildings. And the quantity of waste and emissions generated in the process.Here we are looking at the environmental resources which will be required. Say forexample, for constructing a building we require wood, so we require land from theenvironment, we require forest, we require energy for making the building, we requirestone, we may require water. So, each of this component of the environment is counted itis a resource from which is being borrowed from the environment and that is all whatcounts towards the environmental footprint.(Refer Slide Time: 10:49)The next terminology that we commonly use for defining sustainability and we call themthe 3 hours of sustainability, reduce, reuse and recycle. By reduced it implies that theamount of resource which needs to be consumed has to be reduced it is demandreduction. So, the amount of energy that we require for cooling has to be reduced, theamount of water that is going to be consumed has to be reduced, the amount of materialswhich are going to be used they have to be reduced.So, the first strategy for achieving sustainability not just in buildings, but in any otherdomain is to reduce the resource consumption. Once we have reduced the resourceconsumption, the second strategy which comes is reuse. Whatever is being used has to bereused again. For example, the wood which is in good quality can be reused for someother purpose. Brick can be reused; the construction and demolition waste can be reused. So, the water can be reused and like that. So, the second strategy would be to reuse.FirstFirst, we have reduced the amount of resource required, second is once we haveused the resource it can be reused in some other form.Even after reusing when the waste is generated the third strategy comes into place whichis the recycled. So, the waste out of the first two processes is then recycled to transformit into some other usable form which is the recycling.(Refer Slide Time: 12:37)Another terminology which is also related to these is renewability; recyclable, resourceswe have seen, but renewable resource. Now, renewable resource is a resource that hasthe capability to be naturally and organically replaced in a set period of time. Forexample, using bamboo as a construction material. Now, bamboo as a material it growsvery fast and we can it can is a renewable resource we can use it.For example, the solar energy, the electricity which is generated using the suns energy,so that is a renewable form of energy. It is abundantly and naturally available to us.Electricity which is generated using hydro, the hydropower is a renewable form ofenergy. So, renewable resources are the ones which are naturally replaced or renewed ina such time period.The recyclable resources as we have already talked are the ones where we can transformthe product by some process to make it into a reusable product. (Refer Slide Time: 13:39)Another new concept which we have is off the circular economy. Now, circular economyis very synonymous to sustainability and the system thinking where nothing goes aswaste. So, earlier the approach was to take, make, use, dispose and pollute. So, we takeit, take it from the environment, take the resources from the environment, make it,transform it, use it and then we dispose it off and which eventually goes back to theenvironment to pollute the environment.However, in a circular economy, we have the economic activities and this entire thinggoes in a cyclic manner in a closed loop, where we make use and we reuse it. Afterreusing it we remake it by recycling and make it again, that is how the entire cycle goesin. The economy is associated with it at each step. There are economic opportunitieswhich are generated along with the system within the closed loop. (Refer Slide Time: 14:47)The next very important terminology which we often come across is lifecycleassessment. Now, life cycle assessment is a technique to assess environmental impactassociated with all these stages of a products life that is from the raw material extractionto its processing, manufacturing, distribution, use, repair maintenance and final disposalor recycling. Ideally recycling, but in some cases the disposal. So, the environmentimpact which is associated throughout the products life cycle is taken into account whenwe are talking off life cycle assessment.(Refer Slide Time: 15:37) There are some specific IS is codes ISO 14041, 42 and 43 which defines how lifecycleassessment should be carried out. Very simply, lifecycle assessment requires a goal to bedefined and the scope of the work to be defined. When we talk about life cycleassessment since we have been talking about it since beginning that the entire discussionaround sustainability emerges from this system thinking. So, nothing is isolated, nothingis standing in isolation independently, everything is interconnected.So, when we are talking about life cycle assessment probably there would be no processsystem in the world which is not connected to the other some way or the other. So, wehave to define how much is within the scope of this work. What is the goal? Are welooking at energy? Are we looking at water? Or are we looking at environment largely?Or are we focusing on some other issue?So, depending upon that we define the goal and scope and then we look at the inventorywhatever is existing or whatever is coming in and going out. For example, say a buildingand we define that, ok. We want to look at the life cycle assessment of a building startingfrom its design stage do its post occupancy and demolishing. Now, that is a huge scopeof work.Now, the inventory would be all the raw materials which are coming in, all theoperational resources which are coming in and what is going out as waste as the impacton the environments, all of that will be covered. This is inventory analysis and then wetalk about the impacts what are the impacts, environmental, ecological impacts. All ofthat together is consolidated into one single report and it is reported. This helps indeveloping the strategy plans and the policies related to improvement in the performanceof a product or process or any other activity. (Refer Slide Time: 17:47)Associated with lifecycle assessment there are couple of other terminology which aresynonymously used, but they slightly vary. So, one is cradle-to-grave. Now, cradle-tograve implies the raw material resource extraction from the environment from the naturethat is the cradle and grave implies to the last stage where we are talking about thedisposal, if it is not circular or the recycling where the current form of the product isending and it is being recycled into transformed into some other product. So, that iscradle-to-grave.(Refer Slide Time: 18:47) Cradle-to-grave is the most comprehensive assessment techniques assessment typeswhere the entire life all the phases of a products life are covered. We have others forexample, cradle-to-gate. Now, in cradle-to-gate, we are starting from the resourceextraction the raw material resource extraction, but considering it only up to the gate ofthe factory after the processing and manufacturing is complete before it is transported tothe consumer.So, we are not taking into account how it is being transported, how it is being used,implemented in the building or wherever. So, we are only concerned with the rawmaterial extraction, its manufacturing, processing and its ready to use kind of from up tillfactory gate that is cradle-to-gate. We also have cradle-to-cradle where from cradle-tograve one more step is added where it is circular economy and the loop is closed.So, from one product, the waste of one product we are sending it to the raw material ofthe next product that is cradle-to-cradle approach. The gate-to-gate approach will bewhere the, we are not talking about the manufacture the raw material extraction, we areonly looking at the product from one gate to manufacturing and processing of product toanother gate, where we are not looking at the complete cradle-to-gate or cradle to cradleevaluation, we are only looking at the specific parts of the production process.The next one we are looking at is ecologically based LCA. There is a slight differencebetween the LCA Life Cycle Assessment and ecologically based LCA. In Life CycleAssessment LCA, which we just talked about we are largely looking at theenvironmental impacts, but from a defined scope and perspective.While when we are talking about the ecologically based LCA, we are looking at the at amuch broader range of ecological impacts, possibly all the ecological impacts areconsidered. Here we are not limiting the ecological impacts to a defined scope, thoughthe scope of the work is defined, but all the ecological impacts, which are governedwhich are present within the given scope are concerned considered.Another related terminology which is related to life cycle assessment is life cycle energyanalysis. In life cycle energy analysisanalysis, we are looking at the entire life cycle ofthe product or process, but we are looking only at the energy aspect of it. So, how muchof the energy is consumed from its raw material extraction to its, say disposal orrecycling the through the entire life cycle we are looking only at the energy consumption. So, we are not looking at the environmental impacts, the ecological impacts or any othercosts associated with it, except energy.We are also looking at a synonymous terminology which is Life Cycle Cost AnalysisLCCA. Now, here it is very similar to life cycle energy analysis, but here we are lookingat the cost economic costs of each of the component each of the process. So, we areconverting all the processes and resources which are being consumed during the lifecycle of a product or an activity in terms of its economic value, in terms of its cost andtogether that is a very good measure of comparing product to product.And it is a very effective tool, both life cycle energy analysis and life cycle cost analysisare very effective tool and specially lifecycle cost analysis because we are convertingeverything into the cost numbers which is tangible. AlsoAlso, anything which is resourceexhaustive, it might be any resource for that matter will always have an associated cost.So, cost is a direct measure and hence this terminology, this particular process, thisparticular tool is very effective in calculating in understanding the sustainability.(Refer Slide Time: 23:21)Besides ISO 14041, there is a new code which is in the process of development which isISO 15686 which is the standard which is dealing with the service life planning. Now,here we are looking at a code where it is impacting the decision process, how thedevelopment of the service life of a building component or any other module for thatmatter is taking place. This is still under development and we are looking at the entire life cycle cost profile, weare looking at the entire life cycle assessment, but we are also looking at the policy anddecision side of it which is slightly ahead of 14041. The next tool is designed for theenvironment. It is a design approach which is to reduce the overall human health andenvironmental impact of a product.(Refer Slide Time: 24:18)So, so far in the carbon footprint and through life cycle assessment and analysisapproach, we were mainly looking at the environmental impact, ecological impact of theproduct or process. However, through this approach we are also looking at the impact onhuman health and the overall impact on human health as and environmental impacts aswell throughout the life cycle of the product. (Refer Slide Time: 24:56)The next terminology which we are commonly using is embodied energy. Now,embodied energy is the sum of all the energy required to produce any product or carryout a process. It is mainly use for products, and unlike life cycle energy where we aretaking into account the energy which is being consumed for all the associated processeswhile manufacturing a product. Here we are looking at the energy only for theproduction of a particular material, a very linear process.So, for example, suppose we have we are talking about the embodied energy of cementas a material, so we will be looking at the raw material extraction the amount of energywhich is consumed for the extraction of the raw material, its transportation to the factory,the amount of energy which is required to process this material, and then packing it, andmaking it ready for transporting it to the consumer and then the consumer uses it. So, theenergy which is going in each of these components is counted. But in embodied energywe are not accounting for any energy which is used to mitigate the environmentalimpact.However, when we are looking at life cycle energy analysis life cycle energyapproachapproach, we are also looking at the associated environmental impacts from anenergy point of view. So, for example, suppose we have a lot of heat being dissipated, sothe amount of energy which is further required to capture it or utilize it is also accountedfor an life cycle energy approach, but not in embodied energy approach. (Refer Slide Time: 26:50)The next approach, the next tool is ecodesigneco-design and it is an approach to designproducts with special consideration for environmental impacts of the product during itsentire life cycle. Now, many of these terminologies that we are talking about, they aresynonymous, they are interrelated. It is a new concept this ecodesigneco-design andanother concept which is quite similar to this and very closely associated isenvironmental effect analysis.Here we are taking into account the wishes, the requirements of the customersconsumers, we are also talking about the legal and market requirements. So, we are notjust looking at environment separately in isolation, but we are looking at the social aspectof it. We are looking at the manufacturing process along with the requirement of themarket and the legal requirements as well. (Refer Slide Time: 27:53)Just like we have carbon footprint, we also have terminology which we call as waterfootprint. So, for each of the product and process we consume water and how much isthat water footprint is calculated, in exactly the same manner as we calculate the carbonfootprint or environmental footprint, ecological footprint.So, it can be water footprint can be calculated by adding up the water volume consumedor polluted per unit of time. So, we are not just looking at the water consumed, but weare also looking at the water which is polluted through the process. This is waterfootprint. (Refer Slide Time: 28:42)Now, another terminology which is used is carbon offset or carbon sequestration. So, for1 unit of carbon dioxide equivalent that is reduced or avoided or sequestered.Sequestered implies which is captured back to compensate for emissions occurringanywhere, elsewhere is what carbon sequestration or carbon offset is.Now, there are different strategies within the design which help us to offset this carbonemission or sequester the carbon the best to be plantation of trees. So, leaving land forplanting trees or greenery is a very strong robust method off carbon offsetting or carbonsequestration.All of you must have heard about the concept of ozone depletion. Now, this isdestruction of the earth’s ozone layer by the photolytic breakdown of chlorine orbromine containing compounds which catalytically decomposed ozone molecules. (Refer Slide Time: 29:46)So, there was a lot of discussion, in the previous lectures, we have looked at how ozonedepletion led to the successful assigning of Montreal Protocol and how it led to banningof CFCs, CFC ah compounds whichcompounds which is for ozone for reducing theozone depletion.Now, when we are talking about all these terminologies, we have to directly look at whatis the implication, what is the, how do we understand each of this terminology in thebuilding context. So, when we are looking at say carbon footprint or ozone depletion orcarbon sequestration, we have to look for strategies which can be employed in building,buildings which one say do not deplete ozone or which have lesser global warmingpotential or which have lesser carbon footprint. So, we have to know about each of thesematerials, we have to understand them and then make an informed choice, informeddecision. (Refer Slide Time: 31:04)Another very important terminology that we often use is of sick building syndrome.Many of you might have heard about this sick building syndrome which is which is verycommonly discussed in public, in media. These are buildings where the occupants theyexperience acute health or comfort affects and they are not associated with any specificillness or cause, it cannot be identified yet.People when they spend long hours or substantial duration insight some buildings suchbuildings, this is called as sick building syndrome. Now, this may be because of a lot ofvarious reasons, but primarily all of that can be summed up where the indoorenvironment quality is not good.Now, indoor environment quality may seem a very tangible term, where we may bemonitoring? What is the carbon dioxide level? Wwe may be monitoring w? What is thetemperature? What is the air movement? How much is the fresh air coming in and allthat. But besides thatthat, there are a lot of psychological reasons as well, where peopleare all the time enclosed within the buildings, they do not have visual connect with thenature outside the greenery outside.So, they emotionally psychologically they become sick. So, that is also another type ofsickness. So, all this is clubbed within the sick building syndrome and people do not feelcomfortable or healthy staying in these buildings. (Refer Slide Time: 32:46)We have already talked about these chlorofluorocarbons. These are the chemicalcompounds which are responsible for depleting the ozone layer. So, as architects and asresponsible architects who are aiming to create sustainable buildings, we have to knowwhat are the compounds which can be classified as CFCs, what is there ODP OzoneDepleting Potential and what is that GWP and use the products which have less of suchCFCs or which have less of GWP and ODP.A lot of research is being carried out across the world to look for new materials, newcompounds which can be used as a refrigerants and which have both low GWP and lowODP. Often so far it has been found that compounds which have high ODP have lowGWP and which have high GWP they have low ODP. So, the research is on for findingout new substitutes, new compounds which have both low ODP and low GWP. Now,CFCs are largely used in refrigerants, as refrigerants. (Refer Slide Time: 34:12)The next terminology, which is related to sustainable buildings, is Greenfield andBrownfield. Greenfield project implies that there is no demolishing of an existingstructure required where the land is open, barren; it has not been previously used for anyother purpose. So, it is actually a good for fertile land which can be used for anything.That is a Green Field project.On the other hand, the Brownfield project is a project where we are modifying orupgrading an existing project or may be demolishing and then reconstructing where theland, the project site has already been used for some things. So, that is a Brownfieldproject. So, the quality, the ecological quality of the site has already been altered that is aBrownfield project. So, it is preferred to develop on a Brownfield than a Greenfield,because Greenfield is a good site.Then another common terminology that we use in these green buildings and sustainablebuildings quite often is Energy Performance Index, EPI. (Refer Slide Time: 35:23)And it is the total energy consumed in a building over a year divided by the total built uparea and the unit is kilowatt hour per square meter per year and it is the simplest and themost relevant indicator for qualifying building as energy efficient or not. If you look atthe bureau of energy efficiency website in India, so they have BEE star rating forbuildings and that is actually the numbers which are given are actually EPI numbers,energy performance index numbers and that talks about how much energy in kilowatt is consumed by a