Acta Polytechnica CTU Proceedings https://doi.org/10.14311/APP.2022.38.0656 Acta Polytechnica CTU Proceedings 38:656–671, 2022 © 2022 The Author(s). Licensed under a CC-BY 4.0 licence Published by the Czech Technical University in Prague MEASURING CIRCULARITY FROM BUILDINGS TO NEIGHBOURHOODS Vanessa Gomesa,∗, Sara Valdiviab, Lizzie Pulgrossia, Maristela Gomes da Silvac a University of Campinas, School of Civil Engineering, Architecture and Urban Design, Department of Architecture and Construction, Av. Albert Einstein 951, Cidade Universitária, Campinas – SP, 13083-852, Brazil b University of Campinas, School of Technology, R. Pedro Zaccaria 1300, Limeira – SP, 13484-350, Brazil c Federal University of Espírito Santo, Technology Center, Department of Structures and Buildings, Av. Fernando Ferrari 514 – Goiabeiras, Vitória – ES, 29075-910, Brazil ∗ corresponding author: vangomes@unicamp.br Abstract. The circular economy (CE) aims to eliminate the concept of pollution and waste generation, maintain the integrity of the product over several use cycles, and focus on closing material and energy loops. Circularity metrics are relevant for monitoring, reporting and communicating CE implementation progress. Applied to buildings, these metrics deliver structured assessments through standardized indicators, which establish a common language among the agents involved, help implement strategies to assess the circular potential of technical options. Studies dealing with circularity metrics for buildings are still scarce and somewhat variable within an overall common framework. Applications to neighbourhoods are even more incipient. This study applied selected metrics to two building cases with different constructive characteristics, to improve the understanding on how information on circularity is conveyed. The selected metrics highlighted the circularity challenges for the two building designs. However, such metrics disregard the environmental impacts required to induce circular flows and loop closure. It is herein proposed that such metrics are paired with environmental performance profiles produced by e.g., life cycle assessments (LCA). The concept of “nested indicators” could be applied to neighbourhood and city scales by referring to the LCA concept of functional equivalency as the “relevance” weighting criterion. Keywords: Circular building, indicator, metric, circularity, circular economy. 1. Introduction The circular economy (CE) aims to eliminate the concept of pollution and waste generation so that material circulates in the economy perpetually, that is, it seeks to maintain the integrity of the product over several cycles of use and focus on the closure of material and energy cycles [1]. This helps not only in the security of material supply and sustainable consumption, but also in improving environmental and socioeconomic analyses [2]. This new economic-environmental paradigm has gained relevance in recent years [3]. Indeed, our sys- tematic literature review (see Appendix A) confirmed that this is a trending research topic, and this will con- tinue or intensify. It also showed that this discussion is notably Euro-centred: no article in the final sample focused on e.g., Brazil or South America. In 2015, the European Commission defined a first Action Plan that allocated more than ten billion euros, between 2016 and 2020, for the transition from the current linear model to a circular model [1]. In 2019, the “European Green Deal” was established to address the climate and environmental challenges in Europe and to separate economic growth from the use of resources. In 2020, the European Commission adopted a new action plan and the proposal for a new regulation of sustainable batteries. Finally, in 2021, the Global Al- liance on Circular Economy and Resource Efficiency was launched, and several initiatives were adopted in the action plan [4]. All these measures aim to make the economy of Europe and the world adjust to protect the environment, enhancing competitiveness and circularity, and thus achieving a green future [4]. Despite the debate that has taken place over the last decade, the concept of CE is still being discussed, and remains somewhat confusing, as shown by the over 114 definitions found in a previous review [5]. CE metrics are relevant, as they serve to identify areas in which countries need to focus their efforts to boost their performance in the circular economy [6]. In addition, the EC’s comprehensive performance as- sessment metrics and methods are critical to defining public policy. Therefore, metrics serve to monitor, report and communicate progress towards the imple- mentation of the circular economy [7]. The EC’s concepts apply to companies in all sec- tors [8], and therefore also to the construction indus- try [9, 10]. The construction sector plays a critical but 656 https://doi.org/10.14311/APP.2022.38.0656 https://creativecommons.org/licenses/by/4.0/ https://www.cvut.cz/en vol. 38/2022 Measuring circularity from buildings to neighbourhoods also a strategic role in achieving global environmen- tal, social and economic goals. The Paris Agreement provides for the global decarbonization of the construc- tion sector by 2050, intending to avoid the impact of a 2 °C rise in temperature [4]. From the perspective of circularity, the sector is one of the largest consumers of resources and natural capital, with about 40 % of resource consumption and waste generation [11, 12]. Furthermore, the end-of-life destination of buildings is usually demolition and, at best, recycling the waste generated. Thus, applying CE principles to build- ings allows for considerable benefits to be gained by keeping assets in circulation rather than starting a cy- cle from new resource extraction. For this reason, the European Commission has identified “construc- tion and buildings” as one of the seven main product value chains in its Action Plan for the Circular Econ- omy [13]. In this context, circularity metrics for buildings are a topic of great interest, as they allow managers to identify and control the application of CE practices in the different phases of construction projects, and with what intensity [14]. Furthermore, they implement a common language among all involved actors, which helps to assess the circularity of buildings and monitor the progress of a project according to standardized indicators [15]. Indicators and metrics are also needed to implement strategies to assess the circular potential of the technical options that can be adopted and their efficiency [2]. As circular buildings gain in reputa- tion, the valuation model can be used as a benchmark to compare the performance of buildings based on CE [15]. The lack of indicators and metrics has pre- vented policymakers and stakeholders from setting verifiable recovery targets for new construction and renovation [16]. By providing a meaningful measure of key elements of circular buildings, metrics form the heart of assessment methodologies, and should objec- tively assess and measure the building’s development towards CE and help to improve the performance of buildings, from the initial stages to the end of their useful life, closing the materials cycle [15]. Currently, the most recognized and globally adopted indicator for the built environment is the Material Circularity Indicator (MCI), also known as the the- oretical indicator of circularity of the product. The MCI tool is part of a broader “Circular Indicators Project” developed by The Ellen MacArthur Foun- dation and ANSYS Granta [17] and evaluates the input type, output type and the technical useful life of the materials [17]. In Verberne’s adaptation [18], MCI is the basis for subsequent nested calculations at product (PCI), system (SCI) and building (BCI) levels. PCI incorporates product disassembly possibil- ities and can be referred to as the practical “product circularity indicator”. The System Circularity Indicator (SCI) assesses the circularity of products assembled in a system based on their mass contribution, broken down into the Brand’s six building layers [19]. Lastly, the Building Circularity Indicator (BCI) assesses the set of systems considering a factor for the level of importance each of them has [18]. In the past few years, some BCI improvements have been proposed. Van Vliet [20] proposed to omit the building layers in the PCI cal- culation; Alba Concepts developed a new BCI based on product, element (instead of “system”) and build- ing [21]; and van Schaik [22] slightly modified it to apply to building foundations. Some buildings circularity assessments combine met- rics on reversibility and durability [2], the Building Circularity Indicator (BCI), the new Predictive BCI (Predictive BCI – PBCI) [21] and the Circular Econ- omy Key Performance Indicators of the construction industry (KPIs) to determine to what extent a com- pany implements CE in the different construction projects phases [23]. An expanded list of indicators extracted from the systematic literature review (SLR) can be found in Table 3 (Appendix A). Despite this, there is still a lack of clear definitions to link what characterizes the circularity of buildings to circular construction technologies and to adequate indicators to measure the circular economy [2] and circularity indicators for the built environment as a whole [3]. Hence, two main research questions emerged to be addressed in this paper: • “How clear is the message regarding environmental assessment of the materials flows involved? Which kind of information do the studied metrics con- vey? Do they stand-alone or should be combined to other to communicate environmental performance of buildings and the built environment?”, and • “Can they be aggregated to address larger scales?”. For this purpose, selected metrics were applied to two case studies of different material and constructive characteristics. 2. Method The methodological approach consisted of • a Systematic Literature Review (RSL) to identify existing metrics, as well as their structure, content, components and where they were applied; and • the application of metrics which stood out in the SLR to two case studies; followed by an analysis of the information conveyed and its potential combina- tion to other environmental assessment outcomes. Material Circularity Indicator (MCI), Product Circu- larity Indicator (PCI), System Circularity Indicator (SCI) and Building Circularity Indicator (BCI) were hence selected for application in this study. Two residential buildings were selected as case stud- ies. The first case is a six-story wood-framed building, and the second building is a thirteen-story reinforced concrete structure with masonry walls. For our ex- ploratory purposes, only the structure and envelope components were considered in the calculations. The 657 V. Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings Figure 1. Circularity metrics calculation flow. building lifespan was 50 years, and the materials ser- vice life followed the Brazilian performance standard NBR 15575:2013 [24], and the waste rate was based on Brazilian Association for Recycling of Civil Con- struction Waste data. 2.1. Circularity indicator calculation method The calculations followed the steps in Figure 1, once the products and materials used in each case study, their service life, and mass (kg), virgin input (V) and waste (W) involved were determined. Calculations be- gin by the Linear Flow Index (LFI), the Utility Factor (X) and the Utility Factor Function, F(X). LFI and F(X) are next used to compute the Material Circular- ity Indicator (MCI). The MCI and the Determining Factor of Disassembly (DDF) – that is: the amount of material assembled into systems that can be disas- sembled – feed calculation of the Product Circularity Indicator (PCI). The MCI is also used to obtain the theoretical value for the System Circularity Indicator (SCI (t)), by considering the products’ contribution to the complete system, in mass. Then, the practical value for the SCI (SCI (p)) is calculated using the PCI and the product mass. Finally, the factors accounting for system dependency/level of importance (LK_k) and SCI (theoretical and practical) are considered, to calculate the theoretical (BCI (t)) and the practical (BCI (p)) values of the Building Circularity Indicator. To compute “X”, the buildings were decomposed into six systems (layers). Table 1 is used to compute the systems lifetime (Lsys) and level of importance, a weighting factor between 0 and 1. PCI calculations need the Determining Factor of Disassembly (DDF) nof each product. For that we used Durmisevic’s [25] classification into seven variables (Functional sepa- ration; Functional dependence, Technical life cycle / coordination; Geometry of product edge; Standardisa- tion of product edge; Type of connections; Accessibil- ity to fixings), and assigned values from zero (worst) to 1 (best) impact on disassembly. Finally, to com- System Lifetime Level of [years] importance Site 500 0.1 Structure 100 0.2 Skin 20 0.7 Services 15 0.8 Space Plan 10 0.9 Stuff 5 1.0 Table 1. Lifetime (Lsys) in years and level of im- portance of each system, based on the Brand’s six building layers [19]. pute the BCI (t) and BCI (p), the level of importance (LK_k) of each system is computed (Table 1). 3. Results and Discussion The linear flow index (LFI) offers immediate insight on the potential circularity challenges – i.e., flows with LFI closer to 0, like asphalt or acrylic water- proofing, extruded polystyrene board from external walls or slabs – and accomplishments, i.e., LFI closer to 1, such as steel from window frames and softwood plywood from external walls. The MCI shows how linear a material flow is, also from 0 (linear) to 1 (circular). In Figure 1 and Figure 2, the more the red shape is open, the closer to theoretical circularity is achieved. The wood-framed building has visibly more circularity questions solved than the masonry building, particularly regarding envelope components (Figure 3). Still, apart from the wood elements themselves, the building’s structure uses several items that stress its circularity performance. The lowest result was presented by the floor mortar cement (0.95), which had the shortest estimated lifetime (13 years) within this group of systems (100 years). Materials with longer service life positively affect the utility factor (X) if it suits the system in which the material is inserted. As pointed out by Verberne [18], the ideal 658 vol. 38/2022 Measuring circularity from buildings to neighbourhoods Figure 2. MCI and PCI results – Concrete-framed & masonry building. Figure 3. MCI and PCI results – Wood-framed building. Figure 4. Mass distribution [t] for values the cases studied. Figure 5. Mass distribution [t] for values the cases studied. 659 V. Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings Total Wood-framed building Concrete-framed & masonry building BCI (t) 0.992 0.993 BCI (p) 0.461 0.127 Disassembly potential loss 0,531 0,866 Table 2. BCI results for the cases studied. balance between service life and reusable materials is still subject for future research. As a product that is going to be recycled does not, by definition, mean that it remains functional and can be safely broken down, the PCI highlights those com- ponents with the greatest disassembly potential. The masonry building shows lower indicators, but still with some items that can be disaggregated from the system, mainly envelope components (e.g., stone wool board, XPS board and granite). The wood-framed build- ing showed improved results for disassembly, both for structure (e.g., steel or wood beams) and enve- lope (e.g., aluminium or steel elements, rockwool and prefabricated concrete slab) components. The SCI aggregates the MCI and PCI results, nor- malizing and weighting the results from the mass, to generate a single value that demonstrates a system’s circularity potential. Thus, products with the largest mass contribution influence the SCI results, according to their circularity potential determined in the pre- vious steps (MCI used in the calculation of SCI (t); PCI used in the calculation of SCI (p)). The distance between the theoretical and the practical values indi- cate the potential “circularity losses” created due to limited disassembly. Even in the wood-framed building, concrete use is substantial and responds for about 62 % of the structure mass, followed by the wood beams (floor) summing up to 30 % (Figure 4). Whilst the theoretical SCI value represents a circularity stand close to ideal (MCI ∼1), the practical SCI value is cut by almost half due to the influence of the concrete’s PCI, which is close to zero, despite the good performance of wood elements (PCI ∼1) (Figure 5). The mass of the envelope elements is concentrated by the gypsum panel (34 %) and wood beams (14 %). In the concrete-framed and masonry building, concrete holds 81 % and 44 % of the structure and envelope mass, respectively (Figure 4). Concrete blocks account for 16 % of the envelope’s mass. Such products have low PCI results and therefore push the practical SCI towards linearity (Figure 5). As the BCI (Table 2) factors in the systems’ impor- tance, those with shorter lifetimes – in the case, the envelope products – weight and (negatively) influence the most. Though both buildings have similar BCI (t), the disassembly potential loss (BCI (t) – BCI (p)) is higher for the concrete-framed building (0.866) and reflects the circularity opportunities designed out for the wood-framed building. 4. Conclusions This study’s outcome made clear that – though very intuitive and crucial for societal development peace- making with its supporting environment – circularity metrics do not convey complete environmental infor- mation. By highlighting the renewability, potential re-application and recoverability of materials, they emphasize the use phase, and do not usually consider, for example, the actual impacts to keep materials and energy in the loop. The environmental impacts / costs to reinject potentially returnable material in the industrial loops and transition to circular economy are not accounted for. Increased material and energy circularity might even enlarge life cycle impacts until the full circular economy status is reached. So, it is herein proposed that such metrics are paired with environmental performance profiles produced by e.g., life cycle assessments. As to the second research question posed, the con- cept of “nested indicators” seems to also be smoothly applicable to larger – e.g., neighbourhood and city – scales. A “relevance” weighting criterion is needed and is herein proposed to refer to the life cycle assess- ment concept of functional equivalency. Procedures for applying LCA to neighbourhoods have already been investigated in a few studies, including by some of these authors, and can provide the basis for such extended examination. Acknowledgements The authors thank the National Council of Scientific and Technological Development – CNPq (productivity grant #306048/2018-3; PIBIC grant #135870/2021-6) and the Brazilian Coordination for the Improvement of Higher Ed- ucation Personnel – CAPES (grant #88887.480078/2020- 00). References [1] Ellen Macarthur Foundation. Universal circular economy policy goals: Enabling the transition to scale, 2021. [2022-02-16]. https://emf.thirdlight.com/link/5bli4i8yq0dv- 1ovkaa/@/#id=0 [2] E. Antonini, A. Boeri, M. Lauria, F. Giglio. Reversibility and durability as potential indicators for circular building technologies. Sustainability 12(18):7659, 2020. https://doi.org/10.3390/su12187659 [3] A. Gravagnuolo, M. Angrisano, L. Fusco Girard. 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Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings A. Appendix – Table 3 Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 1 Ve rb er ne , J. J. H . Bu ild in g ci rc ul ar ity in di ca to rs an ap pr oa ch fo r m ea su rin g ci rc ul ar ity of a bu ild in g 20 16 M at er ia lC irc ul ar ity In di ca to r (M C I) T he in di ca to r ev al ua te s in pu t ty pe ,o ut pu t ty pe an d te ch ni ca lu se fu ll ife of m at er ia ls. C ur re nt ly, th e m os t re co gn iz ed an d ad op te d in di ca to r gl ob al ly . Pr od uc t C irc ul ar ity In di ca to r (P C I) T he in di ca to r in co rp or at es pr od uc t di sa ss em bl y po ss ib ili tie s an d ca n be re fe rr ed to as th e pr ac tic al in di ca to r of pr od uc t ci rc ul ar ity . Sy st em C irc ul ar ity In di ca to r (S C I) Th e in di ca to r ev al ua te s th e cir cu la rit y of pr od uc ts in a sy st em ba se d on th ei r we ig ht an d m ak in g a se pa ra tio n ba se d on th e six la ye rs of th e sy st em . Bu ild in g Ci rc ul ar ity In di ca to r (B C I) T he BC Ie va lu at io n m od el is co m po se d of th e M at er ia lC irc ul ar ity In di ca to r (M C I) ,P ro du ct C irc ul ar ity In di ca to r (P C I) ,S ys te m C irc ul ar ity In di ca to r( SC I) an d, fin al ly ,t he C on st ru ct io n C irc ul ar ity In di ca to r (B C I) .B C Ie va lu at es th e se pa ra te sy st em s as a w ho le w ith a fa ct or of im po rt an ce le ve lo fe ac h sy st em . Tw o fic tit io us bu ild in gs (c irc ul ar an d no t ci rc ul ar ). 662 vol. 38/2022 Measuring circularity from buildings to neighbourhoods Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 2 G er ar d Fi nc h, G uy M ar ria ge , A nt on y Pe lo si, M or te n G je rd e Bu ild in g en ve lo pe sy st em s fo r th e ci rc ul ar ec on om y; Ev al ua tio n pa ra m et er s, cu rr en t pe rfo rm an ce an d ke y ch al le ng es 20 21 Bu ild in g C irc ul ar ity In di ca to r (B C I) - C irc ul ar Ec on om y In di ca to r (C EI P) - C irc ul ar Ec on om y In de x (C EI ) - C irc ul ar ity Pe rfo rm an ce In di ca to r (C PI ) - Ec o- effi ci en t Va lu e R at io (E V R ) - En d- of -L ife R ec yc lin g R at es (E oL -R R s) - M at er ia lC irc ul ar ity In di ca to r (M C I) - Pr od uc t- Le ve lC irc ul ar ity M et ric (P C M ) - R eu se Po te nt ia lI nd ic at or (R PI ) - R es ou rc e D ur at io n In di ca to r (R D I) - R ec yc lin g In di ce s (R Is ) - N ew Ze al an d C on st ru ct io n. 663 V. Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 3 Fe lix H ei se l, Sa bi ne R au - O be rh ub e C al cu la tio n an d ev al ua tio n of ci rc ul ar ity in di ca to rs fo r th e bu ilt en vi ro nm en t us in g th e ca se st ud ie s of U M A R an d M ad as te r 20 20 M at er ia lC irc ul ar ity In di ca to rs (M C I) D es cr ib ed ab ov e. M ad as te r C irc ul ar ity In di ca to r T he in di ca to r re gi st er s st oc ks an d m at er ia lfl ow s w ith in a ci rc ul ar bu ilt en vi ro nm en t. Le ve l(s ) - C irc ul ar ity In di ca to r (C I) T he in di ca to r ev al ua te s ea ch bu ild in g’ s ci rc ul ar ity le ve lb et we en 0 an d 10 0 pe rc en t ba se d on us er s. C IC on st ru ct io n T he in di ca to r re pr es en ts th e ra tio of vi rg in m at er ia ls to re cy cle d, re us ed or ra pi dl y re ne wa bl e m at er ia ls. It is ba la nc ed by effi ci en cy in di ca to rs of th e pr oc es s of re cy cl in g pr io r to th e co ns tr uc tio n ph as e an d th e m as so fw as te ge ne ra te d du rin g th e re cy cli ng pr oc es s. C IU se T he in di ca to r re pr es en ts th e lif e ex pe ct an cy of th e pr od uc ts us ed ,c om pa re d to th e av er ag e lif e of pr od uc ts in st at us qu o. T he ac tu al sc or e is de te rm in ed by ca lc ul at in g th e we ig ht ed av er ag e of al lp ro du ct s of th e va rio us la ye rs of th e sy st em . C IE nd of lif e T he in di ca to r re pr es en ts th e re la tio ns hi p be tw ee n wa st e an d re us ab le an d/ or re cy cl ab le m at er ia ls ge ne ra te d w he n a bu ild in g is re no va te d or de m ol ish ed . U rb an M in in g U ni t an d R ec yc lin g (U M A R ) de sig ne d an d bu ilt by W er ne r So be k w ith D irk E. H eb el an d Fe lix H ei se la t N ES T (N ex t Ev ol ut io n of Su st ai na bl e Te ch no lo gi es ) of Em pa D üb en do rf (F ed er al La bo ra to rie s Sw iss M at er ia ls Sc ie nc e Te ch no lo gy ) in Sw itz er la nd . 4 K im be rle e M ar ce llu s- Za m or a, Pa tr ic ia G al la gh er , Sa br in a Sp at ar i C an Pu bl ic C on st ru ct io n an d D em ol iti on D at a D es cr ib e Tr en ds in Bu ild in g M at er ia l R ec yc lin g? O bs er va tio ns Fr om Ph ila de lp hi a 20 20 M at er ia lF ra ct io n (M F) In di vi du al fra ct io ns of m at er ia lw as te . M at er ia lD iv er te d (M D ) O ve ra ll de vi at io n ra te of to ta lm at er ia ls. M un ic ip al wa st e m an ag em en t in di ffe re nt ec on om ie s, in cl ud in g th e Pa ci fic Is la nd s an d A sia n C iti es . 664 vol. 38/2022 Measuring circularity from buildings to neighbourhoods Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 5 D ar io C ot ta fa va , M ich ie l R itz en C irc ul ar ity in di ca to r fo r re sid en tia l bu ild in gs : A dd re ss in g th e ga p be tw ee n em bo di ed im pa ct s an d de sig n as pe ct s 20 21 M at er ia lC irc ul ar ity In di ca to r (M C I) D es cr ib ed ab ov e. C irc ul ar ity In di ca to rs (C I) - Sy st em C irc ul ar ity In di ca to r (S C I) D es cr ib ed ab ov e En vi ro nm en ta l Pr od uc t Pe rfo rm an ce In di ca to rs (E PI ) T he y ai m to in di ca te th e m ac ro ,m es o or m ic ro ch ar ac te ris tic s of a pr od uc t. In di ca do r de Po te nc ia ld e R ec ur so s (R PI ) T he in de x m ea su re s th e in tr in sic va lu e of re us in g a m at er ia l, ta ki ng in to ac co un t st at e of th e ar t re cy cl in g te ch no lo gi es . Pr od uc t C irc ul ar ity In di ca to r (P C I) - Li ne ar Fl ow In de x (L FI ) - In di ca do r de Lo ng ev id ad e (L I) T he in de x in di ca te s th e to ta lt im e th e m at er ia li s he ld in a pr od uc t/ se rv ic e sy st em . Bu ild in g Ci rc ul ar ity In di ca to r (B C I) D es cr ib ed ab ov e. N ew Pr ed ic tiv e BC I( PB C I) Ba se d on th re e le ve ls, na m el y a Pr od uc t C irc ul ar ity In de x (P C I) ,a n El em en t C irc ul ar ity In de x (E C I) an d a Bu ild in g C irc ul ar ity In de x (B C I) . A na ly ze d th e co m po ne nt of bu ild in gs in Si ng ap or e. St ud y of ca se in 8 pl ac es . 6 Ca th er in e D e W ol f, En dr it H ox ha , C or en tin Fi ve t C om pa ris on of en vi ro nm en ta l as se ss m en t m et ho ds w he n re us in g bu ild in g co m po ne nt s: A ca se st ud y 20 20 C ut -o ff m et ho d T he in de x is us ed to ev al ua te th e re cy cl in g of co ns tr uc tio n pr od uc ts . R ec yc lin g ra te T he in de x en co ur ag es re cy cl in g at th e en d- of -li fe st ag e. A bi lit y to be di sm an tle d or re m ou nt ed T he in de x m ea su re s th e re pa ir an d tr an sfo rm at io n re qu ire d du rin g as se m bl y an d di sa ss em bl y, re us e ca n on ly ha pp en if co m po ne nt s ca n be di sa ss em bl ed an d re as se m bl ed . En d- of -L ife (E oL ) - C om m er ci al bu ild in g w ith re us ed co m po ne nt s. K op fb au H al le Bu ild in g 11 8, w hi ch is de sig ne d w ith el em en ts re co ve re d fro m de m ol iti on sit es . 665 V. Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 7 M uh am m ad Bi la l, K hu rr am Iq ba lA hm ad K ha n, M uh am m ad Ja m al ud di n T ha he em , A bd ur R eh m an N as ir C ur re nt st at e an d ba rr ie rs to th e ci rc ul ar ec on om y in th e bu ild in g se ct or : To wa rd s a m iti ga tio n fra m ew or k 20 20 C om pr eh en si ve ut ili za ti on ra te of in du st ri al so lid w as te - R ec yc lin g ra te of re cl ai m ed w as te w at er - To ta la m ou nt of SO 2 em is si on s - To ta la m ou nt of C O D em is si on s - R at e of w as te em is si on s - To ta la m ou nt of w as te w at er di sc ha rg e - W at er co ns um pt io n pe r un it pr od uc t in ke y in du st ri al se ct or s - P as si ng ra te of us ed m at er ia ls ba ck in to th e su pp ly ch ai n - C om pr eh en si ve di sp os al ra te of da ng er ou s w as te - R eu si ng ra te of pr od uc ts /m at er ia ls - Fr es hw at er co ns um pt io n - E ne rg y- sa vi ng am ou nt - R at e of ca rb on fo ot pr in t - Av ai la bi lit y of co m pl et e bi ll of m at er ia ls an d su bs ta nc es fo r th e pr od uc t - P er ce nt ag e co ns um pt io n of re ne w ab le or cl ea n en er gy - O ut pu t of m ai n m in er al re so ur ce - E ne rg y co ns um pt io n - To ta la m ou nt of in du st ri al so lid w as te di sp os al - R ec yc lin g ra te of in du st ri al so lid w as te - R el at iv e im po rt an ce in de x (R II ) - E va lu at io n in de x sy st em fo r th e as se ss m en t of C E at th e re gi on al le ve l T he in de x co nt ai ns 16 in di ca to rs cl as si fie d in to 4 gr ou ps . It in cl ud ed in di ca to rs of E C “r ed uc e” an d “r ec yc le ” pr in ci pl es an d no t th e “r eu se ” pr in ci pl e. - 666 vol. 38/2022 Measuring circularity from buildings to neighbourhoods Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 8 C ar m en D ía z- Ló pe z, M an ue l C ar pi o, M ar ía M ar tín - M or al es , M on ts er ra t Za m or an o D efi ni ng st ra te gi es to ad op t Le ve l(s ) fo r br in gi ng bu ild in gs in to th e cir cu la re co no m y. A ca se st ud y of Sp ai n 20 21 Lo ca lp rio rit y in de x (p j) T he in de x al lo w s kn ow in g an d qu an tif yi ng th e gr ea te r or le ss er we ig ht th at ex pe rt s ha ve gi ve n to re le va nt fa ct or s. C on sis te nc y In de x of th e m at rix (C I) , R an do m C on sis te nc y In de x of th e m at rix (R C I) - To ta lp rio rit y in di ce s Fr om th e lo ca lp rio rit y in de xe s an d th e de te rm in ed we ig ht in g co effi ci en ts ,t he ov er al lp rio rit y in de x is ca lc ul at ed fo r ea ch of th e re le va nt fa ct or s. Le ve l(s ) It is a co m m on Eu ro pe an U ni on fra m ew or k of es se nt ia ls us ta in ab ili ty in di ca to rs to m ea su re th e pe rfo rm an ce of bu ild in gs th ro ug ho ut th ei r lif e cy cl e, en ab lin g re du ct io n of em iss io ns an d ci rc ul ar re so ur ce flo w s. T he to ol ai m s to un ite th e en tir e va lu e ch ai n of th e se ct or ar ou nd a co m m on Eu ro pe an la ng ua ge to im pr ov e th e pe rfo rm an ce of a bu ild in g. T he te rr ito ry of Sp ai n wa s se le ct ed fo r th is st ud y. 667 V. Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 9 M at an M ay er , M ar tin Be ch th ol d 9. D ev el op m en t of po lic y m et ric s fo r ci rc ul ar ity as se ss m en t in bu ild in g as se m bl ie s 20 18 M at er ia l R ec ov er y P ot en ti al In d ex (M R P I) T h e sy st em as se ss es th e re co ve ry p ot en ti al at b ot h m at er ia l an d as se m b ly le ve ls th ro u gh a se ri es of ca te go ri es an d su b ca te go ri es th at is m ai n ly b as ed on q u an ti ta ti ve m at er ia l d at a. U n fa st en in g E ff or t In d ex (U F I) T h e in d ex ev al u at es th e eff or t of re le as in g w id el y u se d fa st en er s. E ff or t is d efi n ed as th e le ve l of co m p le x it y in vo lv ed in ac ce ss in g, u n lo ck in g, re lo ca ti n g an d re m ov in g fa st en er s. T im e (i n se co n d s) an d co st (i n € ) ar e u se d as d is as se m b ly p ot en ti al in d ic at or s T h e in d ex es ti m at es th e p ot en ti al en d -o f- li fe d is as se m b ly p ro d u ct d u ri n g ea rl y d es ig n p h as es . T h e d is as se m b ly p ot en ti al is ca lc u la te d fr om a ti m e p er sp ec ti ve an d co st , u si n g li n k -o ri en te d se q u en ce an al y si s. D is as se m b ly E ff or t In d ex (D E I) T h e in d ex q u an ti fi es en d of li fe eff or t an d d is as se m b ly co st . D is as se m b ly eff or t an d co st is m ea su re d th ro u gh ti m e, to ol s, fa st en in g, ac ce ss , in st ru ct io n , d an ge r an d fo rc e co n si d er ed . D is cr et e in d ex sc or es T h e in d ex co n si d er s th re e m ai n li fe st ag es : D is p os al , d is as se m b ly an d re co ve ry , w h ic h in cl u d es re cy cl in g or re m an u fa ct u ri n g. C on n ec ti on in d ex T h e in d ex ta ke s in to ac co u n t se p ar at io n d am ag e, ty p e of to ol re q u ir ed fo r d is as se m b ly an d d is as se m b ly ti m e. A cc es s in d ex T h e in d ex co n si d er s th e co rr el at io n b et w ee n d is as se m b ly se q u en ce an d p ro d u ct li fe ex p ec ta n cy , as w el l as th e p re se n ce of la ye rs th at li m it ac ce ss to ot h er la ye rs w it h sh or te r li fe ex p ec ta n cy . R ec y cl ab il it y in d ex T h e in d ex in cl u d es n ot on ly th e d ev al u at io n of th e v ir gi n to re cy cl ed co n te n t m ar ke t b u t al so th e re la ti on sh ip b et w ee n th e le ve ls of ca rb on d io x id e em it te d d u ri n g p ro d u ct io n an d re co ve ry . D ev al u at io n ra te of p ro d u ct s T h e av ai la b il it y an d eff ec ti ve n es s of re ve rs e su p p ly ch ai n s an d re cy cl in g te ch n ol og ie s ca n b e ga u ge d b y th e ra te of d ev al u at io n of p ro d u ct s. S u rf ac e tr ea tm en t in d ex S u rf ac e tr ea tm en ts ar e ty p ic al ly ap p li ed to b u il d in g co m p on en ts in or d er to m ee t w ea th er or fi re p ro te ct io n re q u ir em en ts . T h os e co at in gs of te n ad h er e to th e co m p on en t u si n g ch em ic al ag en ts th at cr ea te an ir re ve rs ib le b on d , th u s aff ec ti n g th e m at er ia l re co ve ry p ot en ti al of th e co m p on en t. B io d eg ra d ab il it y in d ex B y d efi n it io n , b io d eg ra d ab il it y is th e p ot en ti al fo r m at er ia ls to b e ch em ic al ly co n su m ed b y b ac te ri a or ot h er b io lo gi ca l ag en ts . T h e ab il it y of tr ea tm en ts to su rf ac e to b io d eg ra d e co n tr ib u te s to it s re co ve ry p ot en ti al . B in d er s in d ex T h e in d ex co n si st s of a b io d eg ra d ab il it y sc or e an d a p ri m ar y C O 2 p ro d u ct io n . A ss em b ly le ve l in d ex T h e m on ta ge as se ss m en t is in h er en tl y m or e q u al it at iv e as it fo cu se s p ri m ar il y on sp at ia l d es ig n as p ec ts . C on n ec ti on ty p e in d ex C on n ec ti on s ar e ty p ic al ly m ea su re d b y co m p ar in g tw o va ri ab le s: re ve rs ib il it y an d d is as se m b ly ti m e. S ep ar at io n d am ag e in d ex D am ag e sc al e w it h 5 va lu es . D is as se m b ly ti m e in d ex E st im at in g d ec on st ru ct io n ti m e is n ot as eff ec ti ve as es ti m at in g p ro d u ct d is as se m b ly ti m e. It is b as ed on fi el d ob se rv at io n s, w it h m or e ex p ec te d re fi n em en ts as m or e in fo rm at io n is co ll ec te d d u ri n g fu tu re p h as es of th e p ro je ct . T o ol ty p e in d ex U se d to co n cr et el y re fl ec t th e ra th er ab st ra ct n ot io n of th e le ve l of eff or t. S in ce eff or t is es se n ti al ly a su b je ct iv e co n d it io n , u se rs ca n fi n d ch al le n ge s in d et er m in in g w h at co n st it u te s a h ig h , m ed iu m , or lo w le ve l of eff or t. C om p on en t in te gr at io n in d ex T h e in d ex li n k s th e d eg re e of p re -a ss em b ly in a gi ve n as se m b ly to it s en d -o f- li fe m at er ia l re co ve ry p ot en ti al . It sh ou ld b e n ot ed th at th e in te gr at io n in d ex d o es n ot fo cu se s on p ar t co u n t as an in fl u en ci n g fa ct or in m at er ia l re co ve ry p ot en ti al , b u t ra th er on th e re la ti on sh ip b et w ee n on -s it e an d off -s it e as se m b ly . E n d -o f- li fe re co ve ry p ot en ti al - E n d -o f- li fe in d ex - A pp lic at io n in wa ll m ou nt s re sid en tia l ou td oo r. 668 vol. 38/2022 Measuring circularity from buildings to neighbourhoods Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 10 Li nd a Br aa km an , Si lu Bh oc hh ib - ho ya ,R ob in de G ra af Ex pl or in g th e re la tio ns hi p be tw ee n th e le ve lo f ci rc ul ar ity an d th e lif ec yc le co st s of a on e- fa m ily ho us e 20 21 Le ve lo fC irc ul ar ity (L oC ) - M at er ia lC irc ul ar ity In di ca to r (M C I) D es cr ib ed ab ov e. D iss as se m bl y D et er m in in g Fa ct or s (D FF ) T he y id en tif y po ss ib ili tie s fo r m at er ia l-i nd ep en de nt di sa ss em bl y in pr od uc t de sig n, fo cu sin g on th e in te gr at io n of fu nc tio ns an d co nn ec tio n ty pe s. Pr od uc t C irc ul ar ity In di ca to r (P C I) D es cr ib ed ab ov e. Sy st em C irc ul ar ity In di ca to r (S C I) D es cr ib ed ab ov e. Bu ild in g Ci rc ul ar ity In di ca to r (B C I) D es cr ib ed ab ov e. Si ng le -fa m ily ho us e in th e N et he rla nd s. 11 Sh iy am in i R at na sa ba p- at hy ,A li A la sh wa l an d Sr in at h Pe re ra In ve st ig at io n of wa st e di ve rs io n ra te s in th e co ns tr uc tio n an d de m ol iti on se ct or in A us tr al ia 20 20 W as te D iv er sio n R at e (W D R ) T he in de x ev al ua te s th e lif e cy cl e wa st e ou tp ut un de r co ns id er at io n fo r wa st e m an ag em en t be nc hm ar ki ng . R es id ua ld ev ia tio n ra te (W D R ) is th e pe rc en ta ge of re sid ua ls di ve rt ed fro m th e la nd fil l th ro ug h di ffe re nt in te rv en tio ns su ch as re us e, re cy cl in g, re pa ir, tr ea tm en t an d en er gy re co ve ry . W as te ge ne ra tio n ra te (W G R ) U nd er st an di ng th e vo lu m e, ty pe an d co m po sit io n of C & D W he lp s wa st e m an ag em en t pr of es sio na ls m ak e in fo rm ed de ci sio ns ab ou t su st ai na bi lit y de ve lo pm en t th ro ug h wa st e m in im iz at io n, w hi ch ha s be en w id el y us ed as a K PI in be nc hm ar ki ng pe rfo rm an ce m an ag em en t wa st e. R ec yc lin g R at e - Ze ro W as te In de x (Z W I) T he y ar e us ed to as se ss th e eff ec tiv en es s of wa st e m an ag em en t pe rfo rm an ce an d he lp m ak e in fo rm ed de ci sio ns ab ou t de ve lo pi ng st ra te gi es to im pr ov e wa st e m an ag em en t pr ac tic es . 12 re sid en tia l pr oj ec ts in th e N ew So ut h W al es an d V ic to ria st at es (A us tr al ia ). 669 V. Gomes, S. Valdivia, L. Pulgrossi, M. G. da Silva Acta Polytechnica CTU Proceedings Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 12 L. Br ag an ça , R .M at eu s O bs ta cl es an d ba rr ie rs fo r m ea su rin g bu ild in g’ s ci rc ul ar ity 20 19 M at er ia lC irc ul ar ity In di ca to r (M C I) D es cr ib ed ab ov e. - 13 C he ng ka ng G ao a, C he ng bo G ao ,K ai hu i So ng ,K ej in g Fa ng Pa th wa ys to wa rd s re gi on al ci rc ul ar ec on om y ev al ua te d us in g m at er ia lfl ow an al ys is an d sy st em dy na m ic s 20 20 D ire ct M at er ia lI np ut (D M I) - To ta lM at er ia lI np ut (T M I) - H id de n Fl ow (H F) - D ire ct M at er ia lO ut pu t (D M O ) - To ta lM at er ia lO ut pu t (T M O ) - G ua ng do ng Pr ov in ce . 14 Er ne st o A nt on in i, A nd re a Bo er i, M as sim o La ur ia an d Fr an ce sc a G ig lio R ev er sib ili ty an d D ur ab ili ty as Po te nt ia lI nd ic at or s fo r C irc ul ar Bu ild in g Te ch no lo gi es 20 20 R ev er sib ili ty R ev er sib ili ty is th e pr op er ty of a pr oc es s, sy st em or de vi ce to re tu rn it to its or ig in al st at e th ro ug h th e tr an sfo rm at io n or di sa ss em bl y of a bu ild in g or pa rt s of it, pr es er vi ng th e m ax im um in te gr ity of re m ov ed ele m en ts an d en su rin g m in im al da m ag e to th os e ke pt in pl ac e. R ev er sib ili ty is re la te d to tim e an d im pl ie s tr an sie nc e. D ur ab ili ty It is th e ow ne rs hi p of a pr oc es s, sy st em or de vi ce to m ai nt ai n its ab ili ty to pr ov id e th e re so ur ce st ha ti ti s de sig ne d fo r ov er tim e. C lo se ly re la te d to th e tim e, du ra bi lit y in di ca te s pe rm an en ce . Lo nd on D es ig n Fe st iv al 20 16 (U ni te d K in gd om ). 670 vol. 38/2022 Measuring circularity from buildings to neighbourhoods Id en ti fie r A ut ho rs T it le Y ea r In di ca do r D es cr ip ti on C as e st ud y 15 Pe dr o N úñ ez - C ac ho U tr ill a, Ja ro sł aw G ór ec ki , Ju an M an ue l M aq ue ir. Si m ul at io n- Ba se d M an ag em en t of C on st ru ct io n C om pa ni es un de r th e C irc ul ar Ec on om y C on ce pt – C as e St ud y 20 20 C irc ul ar Ec on om y K ey Pe rfo rm an ce In di ca to rs (K PI s) Th ey al lo w m an ag er st o id en tif y an d co nt ro lw he th er a co ns tr uc tio n co m pa ny is ap pl yi ng C irc ul ar Ec on om y pr ac tic es in th e di ffe re nt ph as es of th e wo rk s an d w ith w ha t in te ns ity . T he fin al C E in de x C E In de x (C EI ) T he in de x m ea su re s a de gr ee of pr op en sit y of th e co ns tr uc tio n co m pa ny to im pl em en t th e C E (c al le d Sc al e C E) .S ho w s th e m os t lik el y va lu es (s co re ) fo r ea ch in di ca to r, gr ou p of in di ca to rs an d th e in de x so th at th es e va lu es ca n be us ed as cu t off va lu es in th e gr ap hi ca lr ep re se nt at io n in Pa ne ls (S ca le C E) . G en er al C on tr ac to r (G C ) C on st ru ct io n. T ab le 3. C irc ul ar ity in di ca to rs an d m et ric s fo r bu ild in gs ,e xt ra ct ed fr om th e sy st em at ic lit er at ur e re vi ew (S LR ). 671 Acta Polytechnica CTU Proceedings 38:656–671, 2022 1 Introduction 2 Method 2.1 Circularity indicator calculation method 3 Results and Discussion 4 Conclusions Acknowledgements References A Appendix – Table 3