In 1992 the United Nations declared sustainability as the guiding principle for the 21st century [1]. It all stems from the acclaimed report Our Common Future by the World Commission on Environment and Development, released in 1987 [2]. In it, several concerns regarding the future of mankind are discussed, including food security, species and ecosystem protection, poverty as well as energy, among others. Sustainable development, according to the report, is the idea of fulfilling the essential needs of all individuals while also providing them with the chance to improve their lives without hindering future generations’ ability to fulfill their own needs. The three pillars of sustainability are Environmental, Social and Economic (see Figure 1).

The evolution of sustainable development was paired with advancements in technology as well as political actions [3]. An important landmark is the 1992 United Nations Conference on Environment and Development, also known as the Earth Summit, in which 27 principles for sustainable development were established [4]. Later, in 2002, the sustainability agenda was further pushed at the World Summit on Sustainable Development [5], where changes in consumption and production were recognized, as well as the eradication of poverty and the protection and maintenance of natural resources.

Since then, the globalization of sustainable development has been verified across several industries. Examples of such can be found in agriculture [6], energy storage [7], fuel production [8,9], supply chain management [10], chemistry [11], materials [12,13,14,15], water [16], and urban development [17,18], among others.

The Circular Economy has received attention and focus as a viable tool for sustainable development [19]. It helps establish connections between industries where residues can be used in a different process, generating economic value and contributing to the reduction of waste and consumption of materials [20]. The relationship between Circular Economy and sustainability has been studied by Geissdoerfer et al. [21], who found different types of relationships in the literature. Nevertheless, there is a beneficial relationship between both topics.

Buildings and construction have been one of the most fundamental and ancient needs since humanity became sedentary. In the 1990s, the sector was responsible for 40% of the world’s materials and energy consumption [22]. Development of principles for the attainment of sustainable construction was started in this decade, with the development of certification tools like Building Research Establishment’s Environmental Assessment Method (BREEAM) and Leadership in Energy and Environmental Design (LEED)–which will be discussed further below. At the same time, authors started making their proposals, such as Hill and Bowen [23], in 1997. A proposal for sustainable construction under four pillars was made–Social, Economic, Biophysical and Technical. The proposal was criticized by Ofori in the following year, but an agreement on the urgency of consensus and raising awareness of the industry regarding sustainable construction was needed [24]. To date, a consensus on a common taxonomy, namely the number of categories, levels of hierarchy and indicator weighting, has not been achieved. These assessment systems are still in their infancy when compared with the rating tools due to the lack of wide empirical field information.

Presently, the construction sector is still responsible for a significant amount of energy and material consumption [25]. A joint effort from different practitioners in the building field has been achieved to develop new strategies and methods with sustainability in mind. Akadiri et al. [6] proposed three main objectives when developing a sustainable building: Resource conservation, Cost efficiency and Design for Human adaptation [25].

Sustainability can be explored for different types of construction, such as residential, commercial, industrial and infrastructures [26]. The work addresses, however, only the sustainability assessment of buildings.

Sustainability assessment systems are typically based on scientific data, but it is important to also consider national policies and the political context. It is known that sustainability plays an important role in government offices [27]. While local governments are involved in creating and promoting sustainable policies, the lack of indicators to track and assess said implementations exist in both the U.S. [28] and Europe [29]. These systems can help inform and improve current policies by providing governments with information on which measures to implement. As such, a close relationship must be kept between science and political forces.

Given the nature of their work, systems developed by scientists usually tend to undervalue the political dimension and give emphasis to knowledge creation. Gatekeeping also happens in the creation of these systems since only the opinions of people that are “experts” in that field will be considered. In order to increase the credibility of these systems, a new approach to creating sustainability indicators should be implemented that involves both scientists and policymakers. This approach should include open communication with society and the use of voting to determine certain parameters [30].

The sustainability hierarchy of indicators can be divided into four different levels [31]:

Indicator: usually obtained as a measurement/process from primary data. An example of an indicator is the monthly energy consumption of a piece of equipment.

Aggregated Indicator: a combination of components that are defined by the same units. An example of an aggregated indicator is the monthly energy consumption of an entire building.

Composite Indicator: a combination of components that, when tied together, represent a complex concept into a single quantitative value. An example of a composite indicator is the ecological footprint.

Index: usually a single number that encompasses all data analyzed for said assessment. An example of that is the BREEAM rating.

In 2009, Ali et al. [32] used seven different sustainability indicator categories; in this work, Water and Energy Efficiency are the most important categories out of the seven. These weightings were determined by a combination of interviews and decision-making methodology implemented in a software application. This procedure is the most common approach found in the literature.

Bragança et al. [33] proposed sustainability indicators under the three aforementioned sustainability pillars-Environmental, Social and Economic. The authors then grouped the indicators under three levels of hierarchy, with the nomenclature going from top to bottom as categories, indicators and finally, parameters. The methodology developed used equal contribution (same weight) for all the parameters. These authors used, as a baseline for the environmental parameters and indicators, studies by the US Environmental Protection Agency’s Science Advisory Board and by Harvard University [34,35,36].

Heravi et al. [37] presented a literature review on sustainability indicators and selected the ones they found relevant for industrial buildings. After the sustainability indicators nomination, a survey among experts from the petrochemical industry in Iran was conducted to understand the relevance of each indicator in order to develop a holistic framework to evaluate the sustainability of industrial buildings in construction, operation and maintenance, and demolition phases.

Hassan et al. [38] also developed an integrated approach to assess the sustainability of buildings. A Technical category was added to the main three pillars of Sustainability, making them four-main indicators–Environmental, Social, Economic and Technical. The authors swapped the hierarchy order of indicators and criteria. Indicator means the highest level of the hierarchy, which before was named as a category; unfortunately, the lack of a uniform nomenclature leads easily to misunderstandings. Out of the 20 criteria proposed, 6 are subjective. A study case considering three different buildings was conducted using the proposed approach, and the final sustainable index of each building was calculated. This demonstration proved the usefulness of sustainability assessment systems and the potential improvement of the sustainable development of buildings.

The three levels of hierarchy were used later by Hamzah et al. [39], published in 2016, though using different nomenclature. While the three pillars of sustainability were kept as the three main objectives, the bottom layer was known as sub-criteria instead of indicators. After conducting a survey with 24 worldwide experts and using fuzzy AHP (Analytic Hierarchy Process), weightings for all the criteria and sub-criteria were determined. The most important sub-criterion was “Design considerations towards safety,” which is a social sub-criterion. Interestingly enough, the most important environmental sub-criterion was “Environmental design”, which is number seven on Hamzah’s list, weighing less than half of the most important indicator [10]–in work by Hamzah et al. [39], the environmental impact was not yet valorized as it is presently.

Yadegarideh et al. [40] surveyed both academics and building industry workers. The authors proposed six different criteria, each with its sub-criteria. A total of 54 indicators were selected. The DEMATEL (Decision Making Trial and Evaluation Laboratory) method, introduced in 1972, was applied to determine the importance level of each criterion and sub-criteria [41].

The sustainability indicator approach was applied by Stanitsas et al. [42] to manage the construction of projects. After a thorough literature review, 127 potential indicators were identified, which were then validated and reduced to 82 via a survey by six construction management experts. The authors emphasize the need for more empirical studies on the sustainability of buildings due to the lack of a widely accepted strategy for achieving sustainability in construction projects.

Table 1 indicates the relevant literature sustainability assessment methodologies, based on sustainability indicators, together with publication year and the number of hierarchy levels and main categories. Table 1 also displays the lack of agreement on the taxonomy proposed in the literature. A lack of consensus on the number of levels of hierarchy and main categories was verified.

It is known that regional climatic conditions affect the design of the building as well as their energy performance and lifetime [44]. Following that, Agol et al. [45] found that in developing countries, sustainability indicators tend to be overlooked or misinterpreted, as the socioeconomic panorama differs significantly from the ones where these methodologies were initially created. A sustainable assessment model should be able to adapt to the specific context of a project and should have flexible weightings to accommodate different scenarios. This is a common feature of many sustainable rating tools, as shown below.

Parallel to academic research, government-owned/non-profit organizations onset the development of building certification tools. The first building certification tool was developed in the UK in 1990, and it was called BREEAM (Building Research Establishment’s Environmental Assessment Method) [46]. Some years later, France published a new tool, the HQE (High environmental quality), while in 1998, the USA launched the LEED tool (Leadership in Energy and Environmental Design). With the arrival of the new millennium, more certification systems were developed. In Portugal, the LiderA system was disclosed in 2000 and more recently, in 2017, the SBToolPT Urban, a branch of the SBTool, was reported by U. Minho [47,48].

The two best-known rating tools are BREEAM and LEED. BREEAM can be applied to several types of buildings, such as new constructions, infrastructures, in-use or refurbishment, while LEED has different guidelines for building design + construction, residential, operations + maintenance, among others. The present manuscript addresses the International New Construction Documentation by BREEAM and the Building Design and Construction guide by LEED [47,48]. BREEAM International New Construction 2016 has 10 different categories–9 environmental and 1 innovation category–and assessment issues, as shown in Table 2.

Each category has several credits. During the building assessment, the total number of credits achieved is determined. For each category, the fraction of credits obtained (ratio between the number of credits obtained and the maximum number of credits for this category) is multiplied by the category weighting, giving out the category score (in %). Adding the 10 category scores, the final BREEM score is obtained. The final score is then categorized into one of the final six BREEAM ratings, as shown in Table 3.

In order to achieve a given BREEAM rating, the minimum overall score must be met, as well as the minimum standards established for said rating. The LEED certification tool–v4.1 Building Design and Construction–has some similarities to the BREEAM rating tool. Instead of minimum standards, the LEED certification tool has prerequisites and credits for the different categories. The distribution is shown in Table 4, where prerequisites start with an asterisk (*).

▪ The building must be in a permanent location on existing land.

▪ The building must use reasonable LEED boundaries.

▪ The building must comply with project size requirements.

A minimum of 40 points are required to obtain a positive certification. The four levels of certifications are displayed in Table 5.

The developed sustainability assessment tools assigned different names to similar categories. While BREEAM and LEED sustainability assessment tools share common names such as “Energy”, “Water”, and “Materials”, there are some categories that are only found in some of these two tools (for example, LEED has the “Sustainable Sites” category, while BREEAM has the “Management”). Zulkefli et al. [43] compared the indicators of different rating tools and organized them into the primary themes of sustainability (Environment, Social and Economic Indicators). A total of 87 indicators were proposed to assess the sustainability of buildings.

In 2015, the European Commission started the development of a common European approach to assessing the environmental performance of buildings. The proposed tool, which is still under development, is known as Level(s), which is a framework that has core indicators of sustainability for buildings [50]. The tool has been developed with six macro-objectives in mind, as depicted in Table 6.

Out of the 16 core indicators presented in Table 7, 3 of them are composite indicators (Life cycle Global Warming Potential, Construction and demolition waste and materials and Indoor air quality), five of them are qualitative (Lighting and visual comfort, Acoustics and protection against noise, Increased risk of extreme weather events, Increased risk of flood events and Value creation and risk exposure) and one (Bill of quantities, materials and lifespans) is reported as information reporting.

The Level (s) framework is divided into three levels. The first level regards the conceptual design for the building project. It is the simplest level, in which early-stage qualitative assessments are applied to the conceptual design or concepts of the building. The second level covers the detailed design and construction performance of the building. This intermediate level entails quantitative assessments of the designed performance and monitoring of the building. The third and final level encompasses the as-built and in-use performance of the building after completion. It is the most advanced level, and it entails the monitoring and surveying of activity on the construction site and the building, as well as its occupants. The higher the level, the more accurate and reliable the report will be, but the framework is built so that one can choose which level/combination of levels to work at [52].

▪ Whole life cycle and circular thinking;

▪ Closing the gap between design and actual building performance;

▪ Achieving a sustainable renovation;

▪ Sustainability has a positive influence on the market value of a property.

After a thorough literature review, sustainability indicators proposed by the present work were compiled into a single list. They were divided into five levels of weighting, where a higher weight was assigned to the indicators shared by an increased number of reviewed rating systems of sustainability. The indicators with higher weights are shown in Table 8, and the others with the lowest weights are shown in Table 9.

As shown in Table 8, the most prevalent indicators in the Environment pillar are “Renewable energy”, “Thermal comfort”, and “Site selection”. In the Social Pillar, the most used indicators are “Design considerations towards safety” and “Acoustic and noise control”. Finally, in the Economic Pillar, the most mentioned indicator is “Innovation management/new product development”.

Different taxonomies of the sustainability assessment systems proposed by the reviewed authors are one of the hurdles of this research area. The use of different nomenclatures, namely the use of different names for distinct levels of hierarchy (e.g., Hassan et al. [38] vs. Hamzah et al. [39]), can make the study of this research area very complex. These two authors actually use the same names (that is, criteria and indicators) for labeling reversed levels of hierarchy. It is necessary to standardize the names of the different hierarchy levels as well as of the name and number of the main categories, though, leaving room for new categories. These new categories, however, should obey established rules for avoiding over-resolved notation systems.

Figure 1.
The sustainability triangle—Environmental, Social and Economic pillars.

Figure 1.
The sustainability triangle—Environmental, Social and Economic pillars.

Table 1.
Comparison of different levels of hierarchy.

Table 1.
Comparison of different levels of hierarchy.

AuthorNumber of Levels of HierarchyNumber of Main CategoriesNumber of IndicatorsAli et al. [32]2741Bragança et al. [33]3331Heravi et al. [37]2341Hamzah et al. [39]3352Hassan et al. [38]2420Yadegarideh et al. [40]3654Stanitsas et al. [42]2382Zulkefli et al. [43]2387

ManagementHealth and WellbeingProject brief and designVisual comfortLife cycle cost and service life planningIndoor air qualityResponsible construction practicesSafe containment in laboratoriesCommissioning and handoverThermal comfortAftercareAcoustic performance Accessibility Hazards Private space Water qualityEnergyTransportReduction of energy use and carbon emissionsPublic transport accessibilityEnergy monitoringProximity to amenitiesExternal lightingAlternative modes of transportLow carbon designMaximum car parking capacityEnergy-efficient cold storageTravel planEnergy-efficient transport systems Energy-efficient laboratory systems Energy-efficient equipment Drying space WaterMaterialsWater consumptionLife cycle impactsWater monitoringHard landscaping and boundary protectionWater leak detectionResponsible sourcing of materialsWater efficient equipmentInsulation Designing for durability and resilience Material efficiencyWasteLand use and ecologyConstruction waste managementSite selectionRecycled aggregatesEcological value of site and protection of ecological featuresOperational wasteMinimizing impact on existing site ecologySpeculative floor and ceiling finishesEnhancing site ecologyAdaptation to climate changeLong-term impact on biodiversityFunctional adaptability PollutionInnovationImpact of refrigerantsInnovationNOx emissions Surface water run-off Reduction of nighttime light pollution Reduction of noise pollution

Table 3.
BREEAM rating benchmarks.

Table 3.
BREEAM rating benchmarks.

BREEAM Rating% ScoreOutstanding≥85Excellent≥70Very Good≥55Good≥45Pass≥30Unclassified<30

Indoor Environmental QualityLocation and TransportationSustainable Sites* Minimum indoor air quality performanceLEED for neighborhood development location* Construction activity pollution prevention* Environmental tobacco smoke controlSensitive land protection* Environmental site assessment* Minimum acoustic performanceHigh-priority site and equitable developmentSite assessmentEnhanced indoor air quality strategiesSurrounding density and diverse usesProtect or restore habitatLow-emitting materialsAccess to quality transitOpen spaceConstruction indoor air quality management planBicycle facilitiesRainwater managementIndoor air quality assessmentReduced parking footprintGreat island reductionThermal comfortElectric vehiclesLight pollution reductionInterior lighting Site master planDaylight Tenant design and construction guidelinesQuality views Places of respiteAcoustic performance Direct exterior access Joint use of facilitiesWater EfficiencyEnergy and AtmosphereMaterials and Resources* Outdoor water use reduction* Fundamental commissioning and verification* Storage and collection of recyclables construction and demolition* Indoor water use reduction* Minimum energy performance* Waste management planning* Building-level water metering* Building-level energy metering* PBT source reduction-MercuryOutdoor water use reduction* Fundamental refrigerant managementBuilding lifecycle impact reductionIndoor water use reductionEnhanced commissioningBuilding product disclosure and optimization-EDPOptimize process water useOptimize energy performanceBuilding product disclosure and optimization-Sourcing of raw materialsWater meteringAdvanced energy meteringBuilding product disclosure and optimization-Material ingredients Grid harmonizationPBT source reduction-Mercury Renewable energyPBT source reduction-Lead, cadmium, and copper Enhanced refrigerant managementFurniture and medical furnishings Design for flexibility Construction and demolition waste managementIntegrative ProcessInnovationRegional Priority* Integrative project planning and designInnovationRegional priorityIntegrative ProcessLEED accredited professional

Table 5.
LEED certification levels.

Table 5.
LEED certification levels.

LEED CertificationTotal PointsPlatinum80+Gold60–79Silver50–59Certified40–49

Level(s) Macro-ObjectivesDefinition1-

Greenhouse gas and air pollutant emissions along a building life cycle

Minimize the total greenhouse gas emissions along a building’s life cycle, from the cradle to the grave, with a focus on emissions from building operational energy use and embodied energy.2-

Resource-efficient and circular material life cycles

Optimize the building design, engineering and form in order to support lean and circular flows, extend the long-term material utility and reduce significant environmental impacts.3-

Efficient use of water resources

Make efficient use of water resources, particularly in areas of identified long-term or projected water stress.4-

Healthy and comfortable spaces

Create buildings that are comfortable, attractive and productive to live and work in and which protect human health.5-

Adaptation and resilience to climate change

Futureproof building performance against projected future changes in the climate in order to protect occupier health and comfort and to minimize long-term risks to property values and investments.6-

Optimized lifecycle cost and value

Optimize the life cycle cost and value of buildings to reflect the potential for long- term performance improvement, inclusive of acquisition, operation, maintenance, refurbishment, disposal and end of life.

Greenhouse gas and air pollutant emissions along a building’s life cycleUse stage energy performanceLifecycle Global Warming PotentialResource-efficient and circular material life cyclesBill of quantities, materials and lifespansConstruction & demolition waste and materialsDesign for adaptability and renovationDesign for deconstruction, reuse and recyclingEfficient use of water resourcesUse stage water consumptionHealthy and comfortable spacesIndoor air qualityTime outside of thermal comfort rangeLighting and visual comfortAcoustics and protection against noiseAdaptation and resilience to climate changeProtection of occupier health and thermal comfortIncreased risk of extreme weather eventsIncreased risk of flood eventsOptimized life cycle cost and valueLife cycle costsValue creation and risk exposure

Table 8.
Compiled sustainability indicators of the reviewed ratings systems. Higher weighting is related to a higher number of sustainability rating systems that use them.

Table 8.
Compiled sustainability indicators of the reviewed ratings systems. Higher weighting is related to a higher number of sustainability rating systems that use them.

WeightEnvironmentSocialEconomic5Renewable energyDesign considerations toward safetyInnovation management/new product developmentThermal comfortAcoustic and noise controlSite selection4Recycled/reused materialsPublic transportation access & transportation planUse of regional resourcesIndoor air quality performanceThermal comfortDaylight3Climate ChangeVisual qualityCost of constructionNoise PollutionEmployment (social aspects)Energy EfficiencyInfrastructure improvementIndoor air qualityCommunity relationships and involvementCost of operation and maintenancePublic acceptance of the projectVisual comfortStakeholder engagement/managementSustainable development supported by local laws2Climate change adaptation/disaster risk managementPublic ComfortRegional workers and personnelCultural heritageSupply and demand sidesRecycled waterNatural heritageMarketing priceDestruction of the stratospheric ozone layerWorkers and personnel comfortReturn on InvestmentDurability of buildingEfficient lightingPost-occupancy user satisfaction survey (to assess end-user comfort)Direct job opportunitiesSensitive land protectionIndirect job opportunitiesPublic health and safetyEconomic and political stability

Table 9.
Compiled sustainability indicators with the lowest weights (weight equal to 1).

Table 9.
Compiled sustainability indicators with the lowest weights (weight equal to 1).

EnvironmentSocialEconomicWorkers’ and personnel’s health and safetyMigration effectsEffects on national economyLoss of habitats, agricultural farms and treesSocial responsibilityUse of national resourcesConstruction water quality impactSocial action funding/Concepts of social justiceEnhancement in the capacity of infrastructureConsidering the life cycle of products and services to reduce environmental impactsCorporate sustainability and organizational cultureEffects on trade balance (national/regional)Project biodiversityLabor practicesFinancing (loan interests)Environmental impact assessment project reportNeeds assessment of society/peopleOpportunity-costEnvironmental tobacco smoke (ETS) controlHuman rightsCost of equipment and their installationCarbon dioxide monitoring and controlEmployee commitment/commitment in the workplaceDistributed income innovation and technological advanceMinimum IAQ performanceProject independence of political factorsEnvelope InsulationSocial impact reportsStakeholder involvement/participationUse of environmentally friendly refrigerants and cleaning materials, effective and low-carbon cleaning equipment and machineryTransparent and competitive procurement processesTarget marketing and benefitsRenewable raw materialsAbsence of bureaucracy in the workplaceEffective project controlHazardous degradable wastesContractor–supplier relationshipBest practice strategyHazardous non-degradable wastesCommitment to the stakeholders’ needsCustomer-relationship management/Access to a range of customersEnvironmental management systems/policy implicationsWell-defined project scope and project limitationsFlood risk assessment strategy to prevent floodingHolistic view of benefitsScope control through managing changesAir PollutionProduct–service systemsBusiness ethicsViolation of animal’s territoryEmphasis on high-quality workmanshipFacility management Technologies/general improvementsDurable materialsEncourage competitionNon-renewable energyImplementing a quality management systemSupply chain collaborationReuse of processed waterFirst mover advantageEffective strategic planningNon-hazardous recyclable wastesCulture of accountabilityOrganizational cultureNon-hazardous non-recyclable wastesComprehensive contract documentationProject outputs emphasisEnvironmental management plan for impacts by the Project Management Team (PMT)DiversificationAbility to pay and affordabilitySustainable project delivery through project stakeholder managementCompetitive tendering/comprehensive pre-tender investigation of the projectEnvironmental/economics accountingEnvironmental education and trainingAdaptability in project environmentEco-efficiencyIntangible asset managementDeveloping an efficient risk management plan by the PMTConsistent and predictable loadMultidisciplinary/competent Project Management Team (PMT)Up-to-date environmental construction technologies and methodsThe role of trust within the PMTImplementing an effective change management strategyEnvironmental responsibility/justiceFollowing project management phases/processesIdentify and address choke pointsProject manager’s leadership styleEfficient data processing for decision-making practicesAppropriate and flexible environmental design details and specificationsEmploying operational decision-making techniques by the PMTMold PreventionProject monitoring and evaluation by the PMT, though previous experiences in projectsBureaucratic streamliningSustainable maintenanceManaging knowledge and awareness to promote sustainable project delivery (PMT)InternationalizationAcidification potentialManagement considerations toward safetyCargo delivery route & proximityEstablish environmental policy and end-user guide, and manualAffordabilityNeighborhood accessibility and amenitiesExpenditure on R&DLow-carbon designMaximum car parking capacityLifecycle costsGrid harmonizationPlaces of respiteReserve funds