A work breakdown structure for estimating building life cycle cost aligned with sustainable assessment-application to functional costs
Abstract
The tools used for budgeting in the building design phase are still insufficient to address the life cycle of the building in terms of environmental and cost impacts. The main objective of this research is to define a model for extending existing cost databases to accommodate life cycle sustainability assessment. For this, current classification systems are reviewed and a case study has been analysed using the new approach. To this end, a new system of classification of construction information is proposed for the evaluation of early design costs, when data are scarce and the only information available refers to the gross interior area and the plot. The classification organizes the costs in a similar way to the sustainability assessment in EN-15643. A subcategory has been added for revenue, developer costs, and taxes at all stages of the lifecycle. The resulting classification is applied to the functional elements of a secondary school project. In the case study, construction costs represent 21% while the use stage accounts for 72% in a 100-year lifespan. The results show that, starting from generic cost bases, more complex costs and functional costs can be defined at different stages of the life cycle and adjusted to sustainability assessment standards.
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Citation: Vázquez-López, E.; Solís-Guzmán, J.; Marrero, M. A Work Breakdown Structure for Estimating Building Life Cycle Cost Aligned with Sustainable Assessment—Application to Functional Costs. Buildings 2024,14, 1119. https://doi.org/10.3390/ buildings14041119 Academic Editors: Angelo Luigi Camillo Ciribini and Silvia Mastrolembo Ventura Received: 7 March 2024 Revised: 12 April 2024 Accepted: 12 April 2024 Published: 16 April 2024 Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). buildings Article A Work Breakdown Structure for Estimating Building Life Cycle Cost Aligned with Sustainable Assessment—Application to Functional Costs Eduardo Vázquez-López 1, Jaime Solís-Guzmán2and Madelyn Marrero 2,* 1ArDiTec Research Group, Department of Architectural Construction II, Higher Technical School of Building Engineering, University of Seville, Av. Reina Mercedes 4-a, 41012 Seville, Spain; [email protected] 2 IUACC—Instituto Universitario de Ciencias de la Construcción, University of Seville, Av. Reina Mercedes 4-b, 41012 Seville, Spain; [email protected] *Correspondence: [email protected]; Tel.: +34-95455-66-61 Abstract: The tools used for budgeting in the building design phase are still insufficient to address the life cycle of the building in terms of environmental and cost impacts. The main objective of this research is to define a model for extending existing cost databases to accommodate life cycle sustainability assessment. For this, current classification systems are reviewed and a case study has been analysed using the new approach. To this end, a new system of classification of construction information is proposed for the evaluation of early design costs, when data are scarce and the only information available refers to the gross interior area and the plot. The classification organizes the costs in a similar way to the sustainability assessment in EN-15643. A subcategory has been added for revenue, developer costs, and taxes at all stages of the lifecycle. The resulting classification is applied to the functional elements of a secondary school project. In the case study, construction costs represent 21% while the use stage accounts for 72% in a 100-year lifespan. The results show that, starting from generic cost bases, more complex costs and functional costs can be defined at different stages of the life cycle and adjusted to sustainability assessment standards. Keywords: building; life cycle cost; functional costs; early design costs; construction information classification system; work breakdown structure; sustainability 1. Introduction It has become essential for the construction sector to act in order to achieve a sustainable economic model, since it represents 13% of the world’s GDP [ 1 ], 5.4% in the European Union, and 5.7% in Spain [ 2 ]. Furthermore, buildings have a long life cycle, and hence they have an impact, not only when they are first built, but throughout their useful life. For example, the operating costs of buildings can account for more than 40% of their total expenses [ 3 ]. This takes on special significance in the construction of public works, since their costs represent a long-term commitment of public funds [ 4 ]. Life cycle cost (LCC) must be addressed in order to analyse the economic sustainability of construction. In 2014, the European Union introduced the LCC concept in the evaluation of public tenders through Directive 2014/24/EU [ 5 ]. The directive contains criteria for awarding public contracts that include economic, environmental, and social aspects, and places emphasis on the LCC indicator, which makes it possible to control the cost of the construction of the building, and of all the subsequent stages of the life cycle: use, maintenance, and end of life. This indicator is used, among others, in the sustainability assessment of Level(s) [ 6 ] and BREEAM [7]. The LCC indicator is not a new concept; it was first applied in the mid-20th century in the military industry [ 8 ]. In the case of building construction, this requires the adaptation of traditional construction cost databases, and hence it is necessary to clearly define exactly Buildings 2024,14, 1119. https://doi.org/10.3390/buildings14041119 https://www.mdpi.com/journal/buildings
Buildings 2024,14, 1119 2 of 28 to what the LCC refers. Currently, the most prominent standards are the ISO 15686-5 standard [ 9 ] and the EN-15643 standard [ 10 ] (Figure 1). The most notable difference between the two is that for the former, the LCC concept only includes the costs related to buildings from their construction to the end of their life (blue box) and introduces another concept, whole life cycle cost (WLC) where pre-construction costs, revenues and externalities are added. This double definition can understandably lead to major confusion [ 11 ], and it is therefore always necessary to declare under which regulations the calculation of the indicator is to be carried out. In the European standard, as shown in Figure 1on the right-hand side, the LCC concept already includes pre-construction costs and revenues. Buildings2024,14,xFORPEERREVIEW2of30 TheLCCindicatorisnotanewconcept;itwasfirstappliedinthemid‐20thcentury inthemilitaryindustry[8].Inthecaseofbuildingconstruction,thisrequirestheadaptationoftraditionalconstructioncostdatabases,andhenceitisnecessarytoclearlydefine exactlytowhattheLCCrefers.Currently,themostprominentstandardsaretheISO 15686‐5standard[9]andtheEN‐15643standard[10](Figure1).Themostnotabledifferencebetweenthetwoisthatfortheformer,theLCCconceptonlyincludesthecostsrelatedtobuildingsfromtheirconstructiontotheendoftheirlife(bluebox)andintroduces anotherconcept,wholelifecyclecost(WLC)wherepre‐constructioncosts,revenuesand externalitiesareadded.Thisdoubledefinitioncanunderstandablyleadtomajorconfusion[11],anditisthereforealwaysnecessarytodeclareunderwhichregulationsthecalculationoftheindicatoristobecarriedout.IntheEuropeanstandard,asshowninFigure 1ontheright‐handside,theLCCconceptalreadyincludespre‐constructioncostsand revenues. Figure1.Categoriesofoveralllifecyclecost:ontheleft‐handsideaccordingtoISO15686‐5,and,on theright‐handside,EN‐15643.Inthebluebox,thelifecyclecost. ResearchonLCChasreceivedincreasedinterestinrecentdecades,asshownbyGoh etal.[11].Theyreviewed45worksrelatedtotheLCCcalculationofconventionaland greenbuildings.AndIslametal.[12]reviewedover50workswhichadvanceinsimultaneouslyevaluatingLCCandLCAintheconstructionofresidentialbuildings.Among morerecentproposalscanbefoundasystematicclassificationthroughaworkbreakdown structure(WBS)thatconsidersalltheoperatingcostsofabuildingthroughoutitslifecycle,includingitswaterandenergyconsumption,throughaunifiedframeworkthatallows theflowofdesignandconstructioninformationinthecorrectmanagementofthebuilding.Forthis,theOmniclassandMasterformatclassificationsarecombined.ThisWBS‐ basedframeworkaimstocovertheentirelifecycleofanassettoprovideaunifiedclassificationsystemforassetinventory[13]. Intheparticularcaseofthestudyofbuildingstructuresolutions,Abouetal.propose LCCassessmentfordesignselection.Theystudiedreinforcedconcrete,structuralsteel, andcold‐formedsteelframesandcomparedtheresults.Theframeworkisdevelopedin accordancewiththerelevantguidelinesforLCAandsustainabilityandisintendedto supportdecision‐makingatthedesignstage.TheycombineLCCandLCAsimultaneously intheanalysisofthestructure’slifecycle[14].Inamoregeneralway,LCCisemployed inthecreationofaselectiontoolwithdesignvariantsinbuildingconstruction[15].They developedanLCCcalculationtoolinExcel.v2403thatincludesindividualvariantsof buildingdesignswithdifferentinputparameters.ItanalysesthecomponentsorequipmentthathavethegreatestimpactontotalLCC.Italsoassessesthelong‐termeconomic efficiencyofproposedresidentialbuildings.Thecalculationofthecostsofservicing, maintenanceandrenovationofthebuildingelementsisdeterminedforeachelement.This isachievedwithdataontheirservicelife,maintenanceintensity,serviceintensity,and operatingcosts.Finally,thecalculationofthecostsconsistsofapercentageratebasedon theacquisitioncosts. Figure 1. Categories of overall life cycle cost: on the left-hand side according to ISO 15686-5, and, on the right-hand side, EN-15643. In the blue box, the life cycle cost. Research on LCC has received increased interest in recent decades, as shown by Goh et al. [11]. They reviewed 45 works related to the LCC calculation of conventional and green buildings. And Islam et al. [ 12 ] reviewed over 50 works which advance in simultaneously evaluating LCC and LCA in the construction of residential buildings. Among more recent proposals can be found a systematic classification through a work breakdown structure (WBS) that considers all the operating costs of a building throughout its life cycle, including its water and energy consumption, through a unified framework that allows the flow of design and construction information in the correct management of the building. For this, the Omniclass and Masterformat classifications are combined. This WBS-based framework aims to cover the entire life cycle of an asset to provide a unified classification system for asset inventory [13]. In the particular case of the study of building structure solutions, Abou et al. propose LCC assessment for design selection. They studied reinforced concrete, structural steel, and cold-formed steel frames and compared the results. The framework is developed in accordance with the relevant guidelines for LCA and sustainability and is intended to support decision-making at the design stage. They combine LCC and LCA simultaneously in the analysis of the structure’s life cycle [ 14 ]. In a more general way, LCC is employed in the creation of a selection tool with design variants in building construction [ 15 ]. They developed an LCC calculation tool in Excel.v2403 that includes individual variants of building designs with different input parameters. It analyses the components or equipment that have the greatest impact on total LCC. It also assesses the long-term economic efficiency of proposed residential buildings. The calculation of the costs of servicing, maintenance and renovation of the building elements is determined for each element. This is achieved with data on their service life, maintenance intensity, service intensity, and operating costs. Finally, the calculation of the costs consists of a percentage rate based on the acquisition costs. But there are still limitations in the development and validation of LCC estimation. Barriers have been identified such as “varying definitions of LCC calculation methodologies; the availability and standards of data sources, in particular, the misalignment of coding systems for identification and classification of components at various levels of development, proprietary ownership of data, lack of knowledge and skills in team members to produce and/or utilize data sources, and limitations of software” [16]. In the particular case of Spain, The Directive 2014/24/EU has been consolidated into national legislation by means of the Law on Public Procurement [ 17 ]. Prior to the
Buildings 2024,14, 1119 3 of 28 publication of this European directive, the legislation on the contracting of public works only contemplated the evaluation of the construction costs of new buildings. To this end, public administrations regularly publish their construction cost databases, which facilitates the preparation of budgets for new buildings. Costs are calculated per work unit, which is defined as “a construction element formed of basic or auxiliary elements which is carried out by a group of specialists” [ 18 ], as required by the public procurement legislation [ 17 ]. Defining a construction project’s scope and establishing its WBS are the first steps to estimating its costs. Their aims are to classify and code work, however, significant overlapping still takes place, as per surveys performed in the sector [ 19 ]. Construction costs and, to a lesser extent, end-of-life costs are usually the most commonly estimated, although, in general, information regarding the costs of the pre-construction use, maintenance, and end-of-life stages remains scarce and/or unreliable [ 20 ]. As a result, existing cost databases are insufficiently prepared to deal with the assessment of LCC. This research addresses the creation of a Construction Information Classification System (CICS) for the calculation of building LCC in the early design stage that is adapted to international models of sustainability analysis in buildings. To this end, national and international systems are reviewed and compared. From their combination, the new classification organises the information and construction types. This enables the calculation of the LCC required by the legislation on contracts in the public sector [17]. 2. State of the Art 2.1. Analysis of Existing CICS Faced with the challenge of creating a new database of construction information adapted to the calculation of LCC, it is necessary to select the most suitable CICSs. These systems constitute fundamental tools for cost analysis which can be used in both the professional and scientific fields. The international standard ISO-12006-2 [ 21 ] organises and classifies the basic concepts. In addition to cost assessment, if the classification is associated with the standards for the calculation of environmental sustainability it would be possible to carry out economic and environmental calculations with the same system structure [3,22,23]. Afsari and Eastman [ 24 ] compared different CICSs according to their purposes and properties, frameworks, grouping principles, and organisation of classification models. Based on their criteria and adding new elements of evaluation such as scope of use, coding, life cycle, and scope boundaries, a comparison is carried out of the main international systems, focusing, in particular, on the Andalusia region (see Table 1). The criteria are defined below: (1) Scope of use: Sets the geographic scale of use for which the classification model is created. (2) Purpose of the classification model: Initial step in the classification of objects. Identifies the interest for which the classification model has been made [25]. (3) Conceptual framework: The framework on which the classification model is built. Related to higher-level information classification models. (4) Grouping principle: This defines whether the grouping is single or multiple, related to the vision of grouping and classifying objects [ 24 ], by adding whether the classification model is itself a conceptual framework. ISO 12006-2 [ 21 ] classification is employed: resources, processes, results, and properties. (5) Organisation: This defines the item classification organisation in order to distinguish items within a collection [25]. Specifically, these are the information levels of development. (6) Coding: This establishes the coding type, numeric or alphanumeric, of the classification model. (7) Life cycle: This defines the temporal boundaries of the information incorporated into the classification model according to the stages of the building’s life cycle. (8) Scope boundaries: This establishes the physical boundaries of the information incorporated into the classification model. It determines whether the information is
Buildings 2024,14, 1119 4 of 28 about the endogenous and/or exogenous costs of building elements. Endogenous costs refer to the costs related directly to the construction site, while exogenous costs are those necessary for the completion of the project but take place away from the construction site. Table 1. Comparison of Level 0 and Level 1 classification models. The columns stand for (1) scope of use, (2) purpose of the classification model, (3) conceptual framework, (4) grouping principle, (5) organisation, (6) coding, (7) life cycle, and (8) scope boundaries. Level 0: Conceptual framework 1 2 3 4 5 6 7 8 ISO Int Classification per class of objects in the building (objects = resources, processes, result, or property) General frame Mult 12 classification proposals grouped into resources, processes, results, and building properties None Yes En. and Ex. Level 1: Multiple Classes 1 2 3 4 5 6 7 8 OMC NA Organisation and classification of all the information regarding the products of the objects in the building environment in their life cycle ISO 12006-2 ISO 12006-3 [26] MasterFormat, Uniformat, EPIC Mult 15 tables representing different visions of building Num Yes En. and Ex. UNC UK Classification system for all aspects of design and construction process ISO 12006-2, SfB, CAWS, EPIC, CESMM Mult 11 tables Alpha No En. and Ex. EN EU Framework for the evaluation of the sustainability of buildings and civil works Compatible with ISO 12006-2 Mult Unique classification system Alpha Yes En. and Ex. Level 2: Single Class 1 2 3 4 5 6 7 8 ICMS Int International Cost Classification System NRM [27] ISO 12006-2 U Three classification levels, cost category, cost group, cost sub-group Num Yes En. and Ex. CEEC EU Exchange of international construction cost information Construction Professionals U One level Num Yes En. and Ex. UNI NA Organisation of the information around the functional elements of the building. Mainly used for cost estimation Construction professionals. WTO. U 4 hierarchical levels of development Num No En. MAS NA List for the organisation of executed units of work, requirements, products and activities. Mainly used in bids and specifications of work units. Construction Industry Uses U4 hierarchical levels Num No En. ACCD S Work units for execution projects Spanish Public Procurement Legislation U Three cost tables (basics-2 levels, auxiliary-3 levels, and unit costs-4 levels) Alpha No En. Abbreviations: Omniclass (OMC), International Cost Management Standard (ICMS), Conseil Européen des Economistes de la Construction (CEEC), Uniclass (UNC), Masterformat (MAS), New Rules of Measurement (NRM), Andalusian Construction Cost Database (ACCD), International (Int), North America (NA), United Kingdom (UK), International (Int), European Union (EU), Spain (S), multiple (mult), single (U), numeric (Num), alphanumeric (Alph), endogenous (En.), and exogenous (Ex.). Table 1analyses the most representative international and national CICSs and classifies them according to the levels indicated in the ISO 12006-2 standard, which aims to establish a framework for the classification of building information from the point of view of objectoriented programming. At Level 0, there are systems that contemplate a conceptual framework of classification. Level 1 includes those that contemplate multiple types of classifications, such as resources, processes, results, and properties. Lastly, Level 2 includes
Buildings 2024,14, 1119 5 of 28 CICSs that have only one classification type (see Figure 2). A particular case is the EN- 15643 standard, since it is a conceptual framework that contains the assessment of the environmental, social, and economic sustainability of construction with a single information structure throughout the life cycle. The standard development at the building level is currently pending [10]. Buildings2024,14,xFORPEERREVIEW6of30 Figure2.HierarchicalStructureofClassificationModels.Abbreviations:Uniclass(UNC),Omniclass (OMC),ConseilEuropéendesEconomistesdelaConstruction(CEEC),InternationalCostManagementStandard(ICMS),NewRulesofMeasurement(NRM),andAndalusianConstructionCostDatabase(ACCD). InNorthAmerica,twomainclassificationshavebeendeveloped,Masterformatand Uniformat.BothareconductedbytheConstructionSpecificationsInstitute(CSI)andthe ConstructionSpecificationCanadaInstitute[28].Masterformatisthemostwidelyused standardforconstructioninformationclassification,mainlyintheformoftheproductand technicalinformationclassificationofbuildingworkunits.Uniformatislargelyusedfor theestimationofthefunctionalelementcostsofbuildings.Inanattempttounifyconcepts, CSIandCSChavesupported,since2006,theOmniclassclassification,whichstructures informationinacommonformatacrossseveraltables.Thus,theUniformatandMasterformatclassificationsarerepresentedbytheOmniclassinformationinTables21and22, respectively.TheUniformat,Masterformat,andOmniclassclassificationsholdparticular importancesincetheyaresupportedbytheBIM‐IFCbuildingmodels[29]. InGreatBritain,theCommitteeofConstructionProjectInformation(CPIc)created Uniclassin1997,whosemostrecentversionisfrom2015,withtheaimofcreatingaclassificationsystemforallaspectsofdesignandtheconstructionprocessbyintegratingthe ConstructionIndex/SamarbetskommittenforByggnadsfragortables(CI/SfB),theCommonArrangementofWorkSectionsforBuildingsWorks(CAWS),theElectronicProduct InformationCooperation(EPIC),andtheCivilEngineeringStandardMethodofMeasurement(CESMM)[24].UniclassiscurrentlyupdatedbytheRoyalInstituteofBritishArchitects(RIBA)ontheNBSprofessionalplatform[30]. AttheEuropeanlevel,theConseilEuropéendesEconomistesdelaConstruction (CEEC)createdtheCodeofMeasurementforCostPlanning[31].Thecouncilimplements aclassificationofbuildingcoststhatcanbeintegratedwithothernationalclassifications andcanbeemployedtomakeinternationalcostcomparisonsatthemanagementlevel [32].ThisclassificationisusedinEuropeanresearchprojects,suchasLifeCycleCosting andCravezero[33]. Since2017,theInternationalConstructionMeasurementStandardsCoalition(ICMSC)haspublishedtheInternationalConstructionMeasurementStandard(ICMS).This standardisbasedontheNewRulesofMeasurement(NRM),developedbytheRoyalInstitutionofCharteredSurveyors(RICS),andaimstostandardisetheclassificationofconstructioncostsatalllevelsfromlocaltointernationalinordertocomparecostsinaconsistentandtransparentway[34].Thestandardsupportslifecyclecostfromthe2019release. InSpain,therehavebeenseveralCICSsdevelopedoverthelast40yearswithaunifyingexchangeformatcalled.bc3[35].Thisformatisreviewedandupdatedperiodically, andtheSpanishsoftwareusespublicandprivatetoolsforthecreationofprojectbudgets. TheseincludeITECinCatalonia,CYPEinAlicante,ConstructionCostDatabaseofthe Figure 2. Hierarchical Structure of Classification Models. Abbreviations: Uniclass (UNC), Omniclass (OMC), Conseil Européen des Economistes de la Construction (CEEC), International Cost Management Standard (ICMS), New Rules of Measurement (NRM), and Andalusian Construction Cost Database (ACCD). In North America, two main classifications have been developed, Masterformat and Uniformat. Both are conducted by the Construction Specifications Institute (CSI) and the Construction Specification Canada Institute [ 28 ]. Masterformat is the most widely used standard for construction information classification, mainly in the form of the product and technical information classification of building work units. Uniformat is largely used for the estimation of the functional element costs of buildings. In an attempt to unify concepts, CSI and CSC have supported, since 2006, the Omniclass classification, which structures information in a common format across several tables. Thus, the Uniformat and Masterformat classifications are represented by the Omniclass information in Tables 21 and 22, respectively. The Uniformat, Masterformat, and Omniclass classifications hold particular importance since they are supported by the BIM-IFC building models [29]. In Great Britain, the Committee of Construction Project Information (CPIc) created Uniclass in 1997, whose most recent version is from 2015, with the aim of creating a classification system for all aspects of design and the construction process by integrating the Construction Index/Samarbetskommitten for Byggnadsfragor tables (CI/SfB), the Common Arrangement of Work Sections for Buildings Works (CAWS), the Electronic Product Information Cooperation (EPIC), and the Civil Engineering Standard Method of Measurement (CESMM) [ 24 ]. Uniclass is currently updated by the Royal Institute of British Architects (RIBA) on the NBS professional platform [30]. At the European level, the Conseil Européen des Economistes de la Construction (CEEC) created the Code of Measurement for Cost Planning [ 31 ]. The council implements a classification of building costs that can be integrated with other national classifications and can be employed to make international cost comparisons at the management level [ 32 ]. This classification is used in European research projects, such as Life Cycle Costing and Cravezero [33]. Since 2017, the International Construction Measurement Standards Coalition (ICMSC) has published the International Construction Measurement Standard (ICMS). This standard is based on the New Rules of Measurement (NRM), developed by the Royal Institution of Chartered Surveyors (RICS), and aims to standardise the classification of construction costs at all levels from local to international in order to compare costs in a consistent and transparent way [34]. The standard supports life cycle cost from the 2019 release.
Buildings 2024,14, 1119 6 of 28 In Spain, there have been several CICSs developed over the last 40 years with a unifying exchange format called .bc3 [ 35 ]. This format is reviewed and updated periodically, and the Spanish software uses public and private tools for the creation of project budgets. These include ITEC in Catalonia, CYPE in Alicante, Construction Cost Database of the Community of Madrid, BDC-IVE in Valencia, BDEU in the Basque Country, PRECIOCENTRO in Guadalajara, and the Construction Cost Database of Andalusia [23]. In the particular case of this work, its geographical focus is Andalusia, Spain. The CICS of the Andalusian Construction Cost Database (ACCD) is used as a reference [ 36 ]. The database is employed for the cost estimation of architectural projects and it is based on the definition of work unit costs. Its hierarchical costs division is harmonised with the cost structure proposed by Spanish public procurement legislation. This meets the most commonly used decomposition criteria internationally, where the main divisions of WBS for building projects are elements, work sections, physical location, and auxiliary means of construction [37]. 2.2. Coding of the CICSs The coding of a cost database is a key issue in the identification and organisation of the information in an unambiguous way and brings simplicity to the information processing. The use of letters, digits, or combinations thereof has both advantages and disadvantages. Alphabetic characters enable the same number of sub-divisions as the number of letters in the alphabet of each language; for example, in Spanish it would admit 27 sub-divisions. On the other hand, numeric characters only support 10 sub-divisions at each level. Another advantage of letters with respect to digits is that they allow the first letter of each title to be associated with a certain concept but are only identifiable in the language of the titles, and therefore would not provide an intuitive universal coding system. Table 2summarises the coding employed by the CICSs reviewed: Uniclass [ 30 ], ACCD [ 36 ], CEEC [ 31 ], EN-15643 [ 10 ], and the ICMS [ 34 ]. All have alphanumeric classifications, except for the ICMS, which contains numeric characters exclusively. Table 2. Comparison of cost classifications. Name Code Uniclass ZZ-NN-NN-NN-NN ACCD NN-Z-Z-Z-NNNNN EN-15643 Z-N CEEC Z ICMS NN-N-NN-NNN N is for numeric characters and Z is for alphabetic characters. 3. Methodology The main objective of this study is to create a CICS which organises costs throughout the life cycle of buildings, and a model to evaluate costs at a pre-design stage when design data are scarce and only approximate information is available on the needs of the building and its characteristics. First, the new CICS should contain a classification of the stages or categories of the life cycle. To this end, it is proposed that the classification considers the ISO 12006-2 normative framework [ 21 ], the EN-15643 standard [ 10 ], since it is a life cycle structure, and the ISO classification [ 9 ]. The separation of LCC and CGCV concepts in the ISO standard is unnecessary, however, since pre-construction externalities, revenues, and costs can all be included as sub-categories within each stage of the life cycle. Secondly, it is essential to establish a structured definition of a building divided into elements that can be quantified. The division element of buildings that is considered most appropriate for the pre-design phase is the functional unit cost, understood as the cost of the construction element which has a complete function within the project, which is formed by a set of basic, auxiliary, and unitary elements that constitute a construction whole [ 18 ].
Buildings 2024,14, 1119 7 of 28 Each functional element is the consequence of the characteristics, needs, and uses that the building is going to have. Therefore, the cost database will be composed of functional elements of the building, with their corresponding costs of construction, consumption, maintenance, repairs, replacements, and end of life. Regarding the sources of information, it should be borne in mind that the cost information retains its reliability and quality because the costs of functional elements are an aggregation of the costs of basic elements, auxiliaries, and work units, all of which are sufficiently contrasted since they are already part of the existing construction cost databases in use in Spain. In this work, the costs of the basic elements, auxiliaries, and work units are those included in the ACCD, since the final objective is their application in Andalusia (Spain) [ 36 ]. Two types of functional elements are used: functional cells and functional areas. Functional cells are defined as a combination of constructive elements that give shape to a homogeneous functional space, defined by boundaries that guarantee that there are no gaps or overlaps, such as a teaching classroom. Functional areas are an aggregate of cells and are defined as the combination of constructive elements that give shape to a set of homogeneous functional spaces, defined by boundaries that guarantee that there are no gaps or overlaps, such as a classroom building [18]. Thirdly, it is necessary for each functional element to be defined in the context of a building typology, since the technical characteristics can vary considerably. In this respect, the classification of building typologies proposed by the cadastral regulations of Spain has been selected as a reference [ 38 ]. Figure 3provides an outline of the procedure for the creation of the cost database. Buildings2024,14,xFORPEERREVIEW8of30 functionalelementsofthebuilding,withtheircorrespondingcostsofconstruction,consumption,maintenance,repairs,replacements,andendoflife. Regardingthesourcesofinformation,itshouldbeborneinmindthatthecostinformationretainsitsreliabilityandqualitybecausethecostsoffunctionalelementsarean aggregationofthecostsofbasicelements,auxiliaries,andworkunits,allofwhichare sufficientlycontrastedsincetheyarealreadypartoftheexistingconstructioncostdatabasesinuseinSpain.Inthiswork,thecostsofthebasicelements,auxiliaries,andwork unitsarethoseincludedintheACCD,sincethefinalobjectiveistheirapplicationinAndalusia(Spain)[36].Twotypesoffunctionalelementsareused:functionalcellsandfunctionalareas.Functionalcellsaredefinedasacombinationofconstructiveelementsthat giveshapetoahomogeneousfunctionalspace,definedbyboundariesthatguaranteethat therearenogapsoroverlaps,suchasateachingclassroom.Functionalareasareanaggregateofcellsandaredefinedasthecombinationofconstructiveelementsthatgive shapetoasetofhomogeneousfunctionalspaces,definedbyboundariesthatguarantee thattherearenogapsoroverlaps,suchasaclassroombuilding[18]. Thirdly,itisnecessaryforeachfunctionalelementtobedefinedinthecontextofa buildingtypology,sincethetechnicalcharacteristicscanvaryconsiderably.Inthisrespect, theclassificationofbuildingtypologiesproposedbythecadastralregulationsofSpain hasbeenselectedasareference[38].Figure3providesanoutlineoftheprocedureforthe creationofthecostdatabase. Figure3.MethodologicalschemaforthecreationofaCICSforpublicworksprojectsinSpain. Forthecreationoffunctionalcosts,thecasestudyofastatesecondaryschoolbuildinglocatedinAndalusiahasbeenchosen.Basedonthetenderedprojectswiththistypology,thedesignregulationsofthesebuildings,andontheactualcostsofsupplies,the functionalcoststhatcomprisethebuildingsaredefined.Theprojectsanddesignregulationsintheregionprovidethegroundfloorareathatisusuallyrequiredinthedesignof thesebuildings,aswellasthequantitysurveyingofsimilarpreviousprojects.Fordataon suppliesandotherexpenditures,informationisprovidedbytheregionalgovernment. Figure 3. Methodological schema for the creation of a CICS for public works projects in Spain. For the creation of functional costs, the case study of a state secondary school building located in Andalusia has been chosen. Based on the tendered projects with this typology, the design regulations of these buildings, and on the actual costs of supplies, the functional costs that comprise the buildings are defined. The projects and design regulations in the region provide the ground floor area that is usually required in the design of these buildings, as well as the quantity surveying of similar previous projects. For data on supplies and other expenditures, information is provided by the regional government.
Buildings 2024,14, 1119 8 of 28 3.1. The Structure of the New Classification System Firstly, the new structure takes into consideration the Uniclass classification, with levels and tables in accordance with ISO 12006-2 [ 21 ], which facilitates computer processing. Its list of entities contains buildings and civil infrastructures. It also contains a list of spaces and functional elements. Its main disadvantage is that the costs are organised into three different tables. Secondly, the levels established in the ICMS [ 34 ], which focus on the costs of the life cycle of any construction (building or infrastructure) are taken as a reference. It has a limitation in the division into categories of the life cycle however, which is not fully aligned with EN-15643 [ 10 ]. Finally, the ICMS classification is the closest to the objective proposed in this research. From the combination of the above, the levels are proposed in Table 3. The level dedicated to life cycle stages is aligned with EN-15643, another level is for the classification regarding building typologies as suggested by Uniclass [ 30 ] and the ICMS, and a functional group level enables cost elements to be organised, which is common to all reference classifications. Table 3. Comparative structure of the reference and current proposed CICS. Levels of decomposition. Uniclass Levels Table Denomination Level Description Entities Group N1 Grouping of buildings per use Sub-group N2 Sub-division of buildings per use Section N3 Types of buildings Functional Spaces Group N1 Grouping of spaces or locations Sub-group N2 Spaces and locations Functional Elements Group N1 Grouping of Building Elements and Functions Sub-group N2 Elements and functions of the building ICMS Levels Main Levels Level Description Project N1 Types of construction (building and civil) Cost Categories N2 Division according to construction life cycle Cost Groups N3 Construction Division Cost sub-group N4 Sub-division of Cost Groups New Proposal Levels Main Levels Level Secondary Levels Life cycle Categories N1 n.1.1. Categories n.1.2. Sub-categories Functional Groups N2 n.2.1. Functional Groups n.2.2. Functional sub-groups Type of building N3 n.3.1. Type of Family n.3.2. Type of Sub-family n.3.3. Type of Section Level N1 divides the classification into categories within the stages of the building’s life cycle. This level is divided into two sub-levels that are compatible with the levels represented in EN-15643 [ 10 ], which will also allow this classification to be used for environmental or social analysis. Level N2 enables the building to be divided into functional groups and sub-groups and relates them to each stage of the life cycle. Level 3, n3, comprises the building typologies, based on the classification of the Spanish Real Estate Cadastre [ 38 ]. Its sub-divisions of building typologies are hierarchical, from top to bottom, as follows: families, sub-families, and sections. The coding of each element is formed by 10 digits (see Table 4). Numeric characters are used due to the universality of the code. The first two digits correspond to the life cycle categories. The next two digits are the functional groups. The third three-digit block identifies the construction type. And the last three digits establish the order of the
Buildings 2024,14, 1119 9 of 28 functional elements belonging to the same level. Each primary or secondary level defined in the classification structure is assigned a numeric character (see Table 4). Table 4. Numeric coding of the model. N represents a numeric character. Level Digits Description N1 NN Life Cycle N2 NN Functional elements of the building N3 NNN Type of building N4 NNN Order Number N1. N2. N3. N4. NN. NN. NNN. NNN 3.1.1. Level 1—Life Cycle Categories In Level 1, the CICS is structured according to the life cycle of the building, taking the EN-15643 standard as a reference. The first level, Categories, is made up of the following stages of the life cycle: pre-construction, construction, use, and end of life [ 10 ]. The following boundaries are established for each category: - Pre-construction: costs from the completion of the preliminary studies, the acquisition of the land, and its transformation, until the moment at which the construction of the building begins. If the cycle begins with the acquisition of an existing building, only the work prior to its rehabilitation or transformation is included. - Construction: all costs incurred from the beginning of the construction of the building until it is made available for use. - Use: all costs dedicated to the use and maintenance of the building until the construction reaches its end of life. - End of life: all costs necessary for the demolition or deconstruction of the building and the treatment of the waste generated. The second sub-level is Sub-categories, which are those in the EN-15643 standard [ 10 ] with the addition of a further sub-category of fees and taxes, revenues, and other developer related overheads. These costs can be presented at any stage of the life cycle, as shown in Table 5. Another difference with respect to the standard is that the transport sub-categories (A2, C2) are not considered separately, but instead form part of each sub-category. This is due to the fact that, in Spanish traditional cost definitions, transport costs form part of each element of the building. The costs of basic elements always include their transport and unloading costs on site [35]. The boundaries of each sub-category of Level 1 are as follows: - 01. Preliminary actions: The costs related to the purchase of the land where a new building is to be constructed or where an existing building is located. These costs also include all the necessary actions, fees, and management expenses of the developer before the start of the construction work. - 09, 19, 29, and 39. Property developer’s income, taxation, professional fees, and other expenses: All professional fees, taxes, management expenses, and general expenses of the developer. - 11. Building and outdoor spaces: All expenses related to the construction of the building related to the developer–construction contract. - 21. Building use expenses: All contracted expenses and services not included in other sub-categories of building use (e.g., security, alarm, voice, and data installations). - 22. Maintenance: All expenses for inspection, preventive and scheduled maintenance of the building so that it retains its characteristics of use (e.g., cleaning and painting). - 23. Repair: Repair costs for unscheduled breakage or defects of building elements. - 24. Replacement: The costs arising from the replacement of building elements that end their useful life before the end of the useful life of the building.
Buildings 2024,14, 1119 16 of 28 tics (EUR 154.20/m2) [46]. The taxes were taken from local (Seville), regional (Andalusia), and national (Spain) regulations [47]. Table 9. Description of the project floor area. Project General Characteristic Floor Area (m2) Lot size 6.000 Gross external/usable area coefficient 1.15 Total gross external area of buildings 3.450 Total surface area occupied by outdoor spaces 3.942 Total building floor area 2.058 Breakdown indoor spaces (usable area) Specific functional spaces 1510 Multipurpose classrooms 720 Music Lessons classrooms 60 Special education classrooms 50 Plastic art classrooms 60 Workshop classrooms 100 Laboratory rooms 60 Integration support rooms 60 Sport rooms 400 Complementary spaces 750 Circulations spaces 740 Total indoor spaces 3000 Buildings2024,14,xFORPEERREVIEW18of30 Figure6.Examplefunctionalspaces((A).Staircase,(B).Lavatory,(C).Corridor,(D).Lift,(E).Classroom,(F).Terrace). Thedurationofthepre‐construction,construction,andend‐of‐lifestagesis1year each.Theusestagelasts100yearsinordertomeetSpanishrequirementsforconcrete structures[45].Maintenancetaskstakeplaceannuallyexceptforpaintingwhichoccurs everyfiveyears.Repairsareannualandthefollowingsubstitutionsareat20years: HVAC,electronics,bathroomsandkitchens;thefollowingat40years:HVAC,electronics, otherinstallations,bathroomsandkitchens,elevators,enveloperepair,ceilings;andthe followingat70years:thesameactivitiesasat40yearsbut,additionally,thefloorisreplaced. Thefollowingfourhundredandsixtyfunctionalcostsweredefined:fiveforthepreconstructionstage,108fortheconstruction,338fortheusestageandninefortheend‐of‐ lifestage.Theutilitiesconsumptionwasobtainedfromthepublicschoolsystem’sactual data.Thewaterconsumptionis640m3/year,thepowerconsumptionis40,000kWh/year, gasconsumptionis20,000kWh/year,anddataandtelephoniccommunicationsareEUR 790/year.ThecostofurbanlandintheprovinceofSevillewasobtainedfromofficialstatistics(EUR154.20/m2)[46].Thetaxesweretakenfromlocal(Seville),regional(Andalusia),andnational(Spain)regulations[47]. 4.Results Theresultsareobtainedbystagesofthelifecycle,analogoustoenvironmentalproductdeclarations,andbyfunctionalspaces,allowingfortheidentificationofthemostexpensiveelements.Finally,futureinvestmentcostsinthelifeofthebuildingcanbedeterminedfromtheearlydesignstages.Theresultshavebeenobtainedforadiscountrateof 0%and3%,inthecalculationofthe100‐yearLCC(Figure7). Figure 6. Example functional spaces ((A). Staircase, (B). Lavatory, (C). Corridor, (D). Lift, (E). Classroom, (F). Terrace).
Buildings 2024,14, 1119 17 of 28 4. Results The results are obtained by stages of the life cycle, analogous to environmental product declarations, and by functional spaces, allowing for the identification of the most expensive elements. Finally, future investment costs in the life of the building can be determined from the early design stages. The results have been obtained for a discount rate of 0% and 3%, in the calculation of the 100-year LCC (Figure 7). Buildings2024,14,xFORPEERREVIEW19of30 Figure7.ComparisonofLCCcategorypercentageswithdifferentdiscountratesof0%(A)and3% (B). ThemostexpensivestageisB.Use,followedbyA.Construction.Theeffectofthe discountrateinthecalculationsappreciates,sinceitclearlyreducestheinfluenceofthe usestagewhenthe3%discountisapplied.TheA0.Pre‐constructioncostsarealsosignificant,butnotincludedinotherstudies[23]. Analysingthedecompositionofdatafromthedifferentstages,seeFigure8,themost impactingstageofthebuildinglifecycleisB2.Maintenance,followedbyB4.Substitutions,bothwitheconomicimpacthigherthanstagesA1–A4Construction.B3.Repairmentsisthefourthmustimpactingstage.Theutilitiesconsumptionratesarenotvery significantandaresimilartothoseofdeveloperexpensesandtaxation.Itcanbeseenthat thediscountratereducestheimportanceofsubcategoriesB2andB4inthe3%discount rate. Figure 7. Comparison of LCC category percentages with different discount rates of 0% (A) and 3% (B). The most expensive stage is B. Use, followed by A. Construction. The effect of the discount rate in the calculations appreciates, since it clearly reduces the influence of the use stage when the 3% discount is applied. The A0. Pre-construction costs are also significant, but not included in other studies [23]. Analysing the decomposition of data from the different stages, see Figure 8, the most impacting stage of the building life cycle is B2. Maintenance, followed by B4. Substitutions, both with economic impact higher than stages A1–A4 Construction. B3. Repairments is the fourth must impacting stage. The utilities consumption rates are not very significant and are similar to those of developer expenses and taxation. It can be seen that the discount rate reduces the importance of subcategories B2 and B4 in the 3% discount rate. Buildings2024,14,xFORPEERREVIEW20of30 Figure8.Thecostsperlifecyclesubcategorieswith0%(blue)and3%(orange)discountrates. TheresultscanbecomparedtoC.Rivero‐Camachoetal.[3].Theystudiedsocial housinginthesameregionandemployedtheACCDfortheunitcostdata.Theirdiscount ratewas0%.InTable10theirresultsarecomparedtothepresentwork.Althoughthe buildingshavedifferentpurposes,residentialvs.secondaryschool,theresultsaresimilar intermsofpercentage.ItshouldonlybenotedthattheBstageoruseintheschoolbuildingismoreinfluentialthaninthecaseoftheresidentialbuilding.EventhoughRivero‐ Camachoetal.employedtheactualprojectdataandinthepresentworkasimplification functionalcostswereapplied(thosebeingfeedbyunitcostsofthesamedatabase).The resultsshowthatthefunctionalcostscanbeagoodapproximationtotheproject’sLCC. Table10.Comparativeresultsbetweenthesecondaryschoolandasocialhousingproject.Thepercentageofeachstageandinparenthesisthecostpersquaremetre. StageSecondarySchool%(€/m 2 )FourStoriesResidential%(€/m 2 ) A0.Pre‐construction5.5(329.81)11.3(329.81*) A.Construction21.0(1248.66)21.9(635.29) B.Use72.1(4291.73) 65.5(1904.80) C.Endoflife1.4(81.26)1.3(37.36) LCC100(5951.45)100(2907.26) *Thevalueofthelandhasbeenestimatedusingthesamesourceasinthecasestudyinorderto facilitatethepercentagecomparison. 5.Discussion ThenewclassificationconsiderstheISO12006‐2normativeframework[21],theEN‐ 15643standard[10],sinceitisalife‐cyclestructure,andtheISOclassification[9].Butthe separationoftheLCCandCGCVconceptsintheISOstandardisshowntobeunnecessary Figure 8. The costs per life cycle subcategories with 0% (blue) and 3% (orange) discount rates.
Buildings 2024,14, 1119 18 of 28 The results can be compared to C. Rivero-Camacho et al. [ 3 ]. They studied social housing in the same region and employed the ACCD for the unit cost data. Their discount rate was 0%. In Table 10 their results are compared to the present work. Although the buildings have different purposes, residential vs. secondary school, the results are similar in terms of percentage. It should only be noted that the B stage or use in the school building is more influential than in the case of the residential building. Even though Rivero-Camacho et al. employed the actual project data and in the present work a simplification functional costs were applied (those being feed by unit costs of the same data base). The results show that the functional costs can be a good approximation to the project’s LCC. Table 10. Comparative results between the secondary school and a social housing project. The percentage of each stage and in parenthesis the cost per square metre. Stage Secondary School % (€/m2) Four Stories Residential % (€/m2) A0. Pre-construction 5.5 (329.81) 11.3 (329.81 *) A. Construction 21.0 (1248.66) 21.9 (635.29) B. Use 72.1 (4291.73) 65.5 (1904.80) C. End of life 1.4 (81.26) 1.3 (37.36) LCC 100 (5951.45) 100 (2907.26) * The value of the land has been estimated using the same source as in the case study in order to facilitate the percentage comparison. 5. Discussion The new classification considers the ISO 12006-2 normative framework [ 21 ], the EN- 15643 standard [ 10 ], since it is a life-cycle structure, and the ISO classification [ 9 ]. But the separation of the LCC and CGCV concepts in the ISO standard is shown to be unnecessary because pre-construction externalities, revenues, and costs can all be included as subcategories within each stage of the life cycle. ISO 12006-2’s main disadvantage is that the costs are organised into three different tables. For this, ICMS is taken as a reference because it is the closest to the objective proposed in the present research, which focuses on the costs of the life cycle, even though it is not fully aligned with EN-15643. The sub-categories proposed are those in the EN-15643 standard [ 10 ], with the addition of a further sub-category of fees and taxes, revenues, and other developer related overheads. These costs can be presented at any stage of the life cycle. Another difference with respect to the standard is that the transport sub-categories (A2, C2) are not considered separately, but instead form part of each sub-category. This is due to the fact that in traditional Spanish cost definitions the costs of basic elements always include their transport and unloading costs on site [35]. From the combination of the above, the levels are (1) life cycle categories, (2) functional groups and (3) building typologies. The level dedicated to life cycle stages is aligned with EN-15643 [ 10 ], another level is for the classification regarding building typologies as suggested by Uniclass [ 30 ] and the ICMS [ 34 ], and a functional group level enables cost elements to be organised; this is common to all reference classifications. The results show that this new CICS allows the generation of a robust structure that first contains the different stages of the life cycle of the functional element under analysis. Second, it analyses the functional element and establishes clear boundaries, and, lastly, it specifies this element in the building typology, which in this case is a teaching centre. The aggregation of the costs of elements and functional areas generates the structure of the estimate that in turn leads to the determination of the LCC of the building to be analysed. All this suggests that the definition of the functional costs needs to be performed by experts with knowledge of construction and previous experience of the building typology. In summary, in a novel way, the proposed systematic classification covers the entire life cycle, being aligned with the standards for environmental sustainability assessment EN-15643 [ 10 ]. It enables early estimates of life cycle cost, using functional costs in a novel way to estimate construction and maintenance costs. The classification also clearly includes
Buildings 2024,14, 1119 19 of 28 taxes, fees, and financial expenses at different stages of the life cycle. It is the first Spanish work breakdown system that includes all these aspects. 6. Conclusions In order to understand how a CICS is developed, the main international and regional CICSs have been analysed. Their comparison has been carried out using eight criteria: purpose and properties, framework, the principles of grouping, the organisation of the classification models, scope of use, coding, life cycle, and scope boundaries. The comparison reveals a fairly complete picture of the organisation and classification. A new classification is proposed with the following three levels: life cycle categories, functional groups, and building types. The level dedicated to life cycle stages is aligned with EN-15643. The functional group level enables cost elements to be organised, and the third level is for the classification of building typologies as suggested by Uniclass and the ICMS. A cost structure has been possible that defines and meets the objectives for environmental sustainability assessment. The new classification employs the stages of the life cycle of the EN-15643, A0-pre-construction, A-construction, B-Use and C-end-of-life in a way equivalent to that which appears in the environmental product declarations, but at the building level. New sub-categories are included, such as income, professional fees, other expenses of the property developer, and tax costs. This makes it possible to attribute them individually to each stage of the building’s life and to study them in detail. For the evaluation of costs during the early stages of the design, these are defined as functional costs. For their definition, it is necessary to gather information from similar previously tendered projects, from the design regulations, and from the actual costs of supplies from construction cost databases. The case study of a secondary school project in Andalusia shows that the use stage is important as compared to other costs. This makes crucial the correct definition of all future repair work and maintenance tasks, as well as the utility consumption of the building. The new CICS can be aligned with the sustainability assessment stages. In future work, the methodology will be applied to entire building projects, and will define their cells and functional spaces in order to carry out the complete life cycle cost assessment procedure. This can be performed for a variety of building typologies, such as residential buildings, offices, and educational centres, in order to determine whether this classification effectively covers the LCC in the early stages of design. Furthermore, the influences of inflation, discount rates, and life cycle duration could also be taken into consideration. The integration of this classification system into the determination of the LCC indicator is also proposed in evaluation tools such as Level(s) and BREEAM, as is its integration into BIM environments regarding the functional costs created. Likewise, future research is proposed regarding the in-depth determination of LCC in terms of the new CICS. Author Contributions: Conceptualization, E.V.-L.; methodology, J.S.-G.; validation, J.S.-G.; formal analysis, M.M. and E.V.-L.; investigation, E.V.-L.; writing—original draft preparation, E.V.-L. and M.M.; writing—review and editing, M.M. and J.S.-G.; funding acquisition, M.M. All authors have read and agreed to the published version of the manuscript. Funding: Ayudas a la Internacionalización de la Investigación IUACC 2023 del VII Plan Propio de Investigación y Transferencia de la Universidad de Sevilla. Data Availability Statement: The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors. Acknowledgments: The authors would like to thank the I.E.S Palomares staff for their help in data collection and A. Ramírez de Arellano for his support and advice. Conflicts of Interest: The authors declare no conflicts of interest.
Buildings 2024,14, 1119 20 of 28 Appendix A Table A1. Sections of the division of building typologies (NN.NN.NNN. NNN), bolded the location of the code. Classification Boundaries 1Commercial, offices, and parking Buildings intended for commercial use, offices, and parking 11 Bureaux Buildings with the purpose of providing professional, management or administrative services 111 Bank Buildings for the purpose of providing banking services 112 Administrative Buildings for the purpose of providing professional or administrative services 113 Institutional Institution Management Building 119 Others Office buildings not previously contemplated 12 Commercial Buildings intended for the sale of products or services 121 Commercial premises Buildings intended for the sale of products or services located on the ground floor 122 Shopping centre Buildings intended for a group of shops or that are a single shop on several floors 129 Others Commercial buildings not previously contemplated 13 Parking Buildings or spaces intended for vehicle parking 131 Underground parking Below-ground parking building 132 High-rise parking Building for parking above ground 139 Others Other types of parking buildings 19 Others Commercial buildings or offices not included above 199 Others Other buildings 2 Sports facilities Buildings intended for sport activities 21 Golf courses Ground area and buildings intended for golf 211 Golf course Ground used for golf 219 Others Others 22 Tracks Ground area and buildings intended for outdoor sports on tracks 221 Arid Tracks of arid material 222 Lawn Natural grass courts 223 Monolayer Single-layer rigid tracks 224 Multilayer Multi-layered tracks 225 Special Natural grass courts 229 Others Other Clues 23 Stadiums and grandstands Buildings intended to house the public for sporting events 231 Stadiums Large enclosure with grandstands for sports activities 232 Covered grandstands Covered area to accommodate the public 233 Outdoor grandstands Uncovered enclosure to accommodate the public 239 Others Others
Buildings 2024,14, 1119 21 of 28 Table A1. Cont. Classification Boundaries 24 Pools Buildings intended for water sports developed in swimming pools 241 Indoors Indoor swimming pool area 242 Outdoors Outdoor swimming pool enclosure 249 Others Others 25 Sports hall Buildings intended for the exercise of various indoor sports 251 Sports hall Buildings intended for the exercise of various indoor sports 259 Others Others 26 Gymnasium Buildings where gymnastics is practiced 261 Gymnasium Buildings where gymnastics is practiced 269 Others Others 29 Others Sports buildings not described above 299 Others Others 3 Hospitality industry Buildings intended for hotel and restaurant use 31 Lodging Buildings intended for the accommodation of people 311 Tourist apartments Residential space or building dedicated to hospitality in an urban environment 312 Bed and Breakfasts Residential space or building dedicated to hospitality in a rural environment 313 5-star hotels 5-star hotel category 314 4-star hotels 4-star hotel category 315 Other hotels, and hostels Other categories of hotels or hostels 319 Others Others 32 Catering Spaces or buildings intended for the consumption of beverages and food 321 Bars Drinks service taken while standing 322 Cafes Food and beverage service without kitchen 323 Restaurants Meal service with tables and kitchen 329 Others Others 39 Others Hospitality spaces or buildings not mentioned above 399 Others Others 4 Warehouses Large-capacity buildings intended for manufacturing, storage, agricultural production, or commerce 41 Open Warehouse with an open façade 411 Agricultural Warehouse for agricultural use 419 Others Warehouse not previously described 42 Closed Warehouse with all façades closed 421 Agricultural Warehouse for agricultural use 422 Industrial Warehouse for industrial use 423 Commercial Warehouse for commercial use 424 Warehouse Warehouse for storage 425 Logistics Warehouse for logistics storage 429 Others Others 49 Others Warehouse not previously described 499 Others Others
Buildings 2024,14, 1119 22 of 28 Table A1. Cont. Classification Boundaries 5 Leisure Buildings intended for both indoor and outdoor leisure 51 Covered Buildings intended for indoor leisure 511 Social club Meeting Spaces 512 Discotheques Rooms dedicated to nightlife 513 Gaming floors and casinos Spaces intended for gambling 514 Theatres and cinemas Exhibition space for theatrical or cinematographic works 515 Palais des Congrès Building for holding congresses and exhibitions 519 Others Other leisure spaces not identified above 52 Open air Outdoor spaces or buildings 521 Auditorium A space dedicated to the gathering and representation of artistic works in the open air 522 Bullring Space dedicated to the practice of bullfighting 529 Others Others 59 Others Other typologies not described above 599 Others Others 6 Teaching and cultural Buildings designed to house educational and cultural spaces 61 Teaching buildings Building intended for pre-university teaching activity 611 Nursery schools Space dedicated to teaching between 0- and 2-year-olds 612 Infants and primary Building dedicated to teaching between 3- and 12-year-olds 613 Secondary school Building dedicated to teaching between 13- and 17-year-olds 614 Vocational training cycles Building dedicated to professional education 619 Others Others 62 University Building intended for university teaching activity 621 Lecture Hall Building intended for university face-to-face teaching 622 Faculty or School A building intended for the university teaching of certain subjects 623 Research Centre Building for research in the university environment 629 Others Others 63 Cultural Building for cultural activities not idle 631 Libraries Building for archiving, classifying, and consulting bibliographic material 632 Municipal art centres Building intended for cultural uses 633 Museums Exhibition space for artistic objects 639 Others Various cultural buildings 64 Religious Building or space intended for religious worship 641 Religious Building for worship and religious gatherings 649 Others Others religious buildings 69 Others Educational, cultural, and institutional buildings not included above 699 Others Others
Buildings 2024,14, 1119 23 of 28 Table A1. Cont. Classification Boundaries 7 Residential Buildings intended for residential use 71 Residential block High-rise multi-family residential buildings 711 Isolated High-rise dwellings without party walls in common with another building 712 Attached High-rise dwellings with party walls in common with another building 719 Others Others 72 Single-Family homes Single-family residential buildings 721 Isolated Single-family homes without party walls in common with another building 722 Attached Single-family homes with party walls in common with another building 729 Others Others 79 Others Other type of residential building 799 Others Others 8 Health and welfare Buildings intended for health or welfare use 81 Clinic and health centres Buildings or spaces dedicated to primary care or family medicine 811 Consulting room Spaces for consultations and patient care 812 Health Centre Building for outpatient consultations and treatment 819 Others Miscellaneous primary care 82 Hospitals Building for the diagnosis, treatment, and accommodation of patients 821 Hospitals Building for the diagnosis, treatment, and accommodation of patients 829 Others Others 83 Health clinics Establishment dedicated to the diagnosis and treatment of diseases 831 Physiotherapy Establishment dedicated to the treatment of trauma or injury 832 Dentistry Establishment dedicated to dental treatment 833 Ophthalmology Establishment dedicated to eye treatment 834 Radiology Diagnostic facility using radiology 839 Others Others 84 Geriatrics Building intended for geriatric accommodation 841 Day care centres Geriatric day-stay building 842 Geriatric residence Geriatric housing building 849 Others Others 85 Funeral Building intended for the burial or treatment of corpses 851 Funeral homes Building intended for the treatment of corpses prior to burial 852 Cemetery Space for the burial of corpses 859 Others Others 86 Prison Construction of a prison for offenders 861 Prison Construction of a prison for offenders 862 Juvenile offenders centre Construction of detention centre for juvenile offenders 869 Others Others
Buildings 2024,14, 1119 24 of 28 Table A1. Cont. Classification Boundaries 87 Veterinarian Space for the treatment of animals 871 Veterinarian Space for the treatment of animals 879 Others Others 89 Others Other healthcare spaces not included above 899 Others Other healthcare spaces not included above 9 Urbanisation Land preparation for building plots (only actions that cannot be assigned to a single building) 91 Terrain Preparation of rural land for its transition to urban 911 Terrain Develop a plot of land 919 Others Others 99 Others Others 999 Others Others Appendix B Table A2. Example of construction cost of functional cell. 1153613001 m2Corridor Corridor of a secondary school, including cladding (except partitions with uses) and installations from distribution. Measured in terms of usable area. Code Unit Concept Quantity Cost (€) Amount (€) 10STS90010 m2Terrazzo floor with small grain 40 cm ×40 cm 1.00000 21.28 21.28 10SER00001 m2Stainless steel skirting board 2 mm and 7 cm 1.00000 11.64 11.64 09TSS00010 m2 Insulation of rigid polyester plank floors Extended 20 mm 1.00000 6.74 6.74 10TWW90013 m2Roof acoustic panels, removable and concealed truss 0.53776 62.81 33.78 10TWW00011 m2Continuous ceiling with laminated plasterboard 0.46224 20.15 9.31 09TTT00100 m2Insulated felt roofs with fibreglass, 20 mm 1.00000 15.94 15.94 13EAA00001 m2Smooth acrylic elastomer paint 0.46224 3.67 1.70 08ETT00003 unit 16 A recessed power socket with 2.5 mm20.03789 37.06 1.40 08PIS00031 unit Emergency lighting and signal equipment, 160 lumens 0.04547 72.68 3.30 08WII00135 unit Recessed luminaire 2 tubes 40 W. 30 mm ×30 mm 0.09095 125.28 11.39 08PID00101 unit Push button for manual surface alarm triggering 0.01137 22.07 0.25 08PIE90023 unit Mobile fire extinguisher, ABC powder, 6 kg 0.03032 28.74 0.87 08PID90200 unit Indoor buzzer 0.01137 21.89 0.25 08PIS90107 unit Label 297 mm ×210 mm 0.06442 10.74 0.69 08PIE90013 unit Fire hydrant 25 mm diameter and cabinet 0.01137 501.84 5.71 08DA00201 unit Indoor speaker 0.02274 120.29 2.74 Total 126.99
Buildings 2024,14, 1119 25 of 28 Appendix C Table A3. Example of the cost of maintaining functional space. 2353613001 m2Annual Corridor Maintenance Annual maintenance of corridors including the revision and maintenance of fire extinguishers and BIEs. Measured in terms of usable ground area Code Unit Concept Quantity Cost Amount 20IPC00001 unit Revision and maintenance of manual fire extinguisher up to 6 kg 0.03032 3.79 0.11 20IPC00005 unit Overhaul and maintenance of equipped fire hydrants 0.01137 7.57 0.09 Total 0.20 Appendix D Table A4. Example costs of functional space repairs. 2353613001 m2Corridor repairs annually Annual repairs in the corridor of a secondary school including cladding (except divisions with uses) and installations from distribution. Measured in terms of usable ground area of the functional space Code Unit Concept % Rep. Quantity Cost Amount 10STS90010 m2Terrazzo floor with small grain 40 cm ×40 cm 0.13 0.00130 21.28 0.03 10SER00001 m2Stainless steel skirting board 2 mm and 7 cm 0.13 0.00130 11.64 0.02 09TSS00010 m2Insulation of floor with rigid polyester plank, 20 mm thick 0.13 0.00130 6.74 0.01 10TWW90013 m2Roof acoustic panels, removable and concealed truss 0.08 0.00043 62.81 0.03 10TWW00011 unit Continuous ceiling with laminated plasterboard 0.08 0.00037 20.15 0.01 09TTT00100 unit Roof Insulation with fibreglass felt, 20 mm thick 0.08 0.00080 15.94 0.01 13EAA00001 unit Smooth acrylic elastomer paint 0.08 0.00037 3.67 0.00 08ETT00003 unit 16 A recessed power socket with 2.5 mm21.00 0.00038 37.06 0.01 08PIS00031 unit Emergency lighting and signal equipment, 160 lumens 1.50 0.00068 72.68 0.05 08WII00135 unit Recessed luminaire 2 tubes 40 W, 30 mm ×30 mm 1.50 0.00136 125.28 0.17 08PID00101 unit Push button for manual surface alarm triggering 1.00 0.00011 22.07 0.00 08PIE90023 unit Mobile fire extinguisher, ABC powder, 6 kg 8.30 0.00252 28.74 0.07 08PID90200 unit Indoor buzzer 1.00 0.00011 21.89 0.00 08PIS90107 unit Label 297 mm ×210 mm 2.00 0.00129 10.74 0.01 08PIE90013 unit Fire hydrant 25 mm diameter and cabinet 2.00 0.00023 501.84 0.12 08DA00201 unit Indoor speaker 2.00 0.00045 120.29 0.05 Total 0.59 Appendix E Table A5. Example of costs of replacements in functional space. 2353613071 m2Replacements year 70. Corridors Year 70 replacements in corridors of construction elements including floors, ceilings and installations including demolition, excluding floor insulation and painting (maintenance). Measured in terms of usable ground area of the functional space Code Unit Concept Quantity Cost Amount 10STS90010 m2Terrazzo floor with small grain 40 cm ×40 cm 1.00000 21.28 21.28