A Framework for Building Sustainability Assessment for Developing Countries Using F-Delphi: Moroccan Housing Case Study

Abstract

International building sustainability assessment tools (BSATs) offer a comprehensive framework for assessing environmental, economic, and social sustainability. However, these tools cannot fill the gap between their standards and the regional needs of developing countries such as Morocco. This paper presents a new framework to assess the sustainability of buildings in Morocco. The methodology proposed is the Fuzzy Delphi method to minimize the list of indicators with the help of 14 local experts and give an appropriate weight to the indicators and sub-indicators. The two-round analysis found a balanced weighting for the environmental, economic, and social dimensions, with the social pillar ranked highest in importance. A hierarchical framework of six consensus-based categories and 63 sub-indicators was developed. Consensus was measured using the dispersion threshold approach ≤ 0.2. The results show that waste and pollution (0.80), adaptability and resilience (0.78), and resources (0.75) are prioritized over the innovation category. Notably, sewage management, water reuse, and public infrastructure emerged as critical sub-indicators. A comparative evaluation against local BSATs from the region—Ethiopia, Sub-Saharan Africa, Saudi Arabia, and Oman—revealed convergence in core indicators like energy and water, yet divergence in economic and resilience criteria, reflecting regional specificities. This work contributes to the literature by presenting a validated, expert-driven assessment tool that aligns with local needs, offering a practical basis for national green certification and sustainable housing policy in Morocco and similar contexts.

1. Introduction

Existing building sustainability assessment tools (BSATs) are either international, such as LEED, BREEAM, and WELL [1], or nationally focused, e.g., VERDE, ESTIDAMA [2,3]. The African continent represents a challenging context into which to implement the international exigencies [4]. The national ones benefit the specific needs of the targeted country or region. Thus, African countries need a specific BSAT that responds to the region’s problems [5]. The majority of BASTs are issued from developing countries and give priority to environmental categories such as land sustainability [6], while categories related to culture, governance, and socio-economic issues are not present or prominent [7]. The focus on energy and environmental issues is necessary in the African context but is not the most important indicator of African dwellings [8]. Safety, amenities, and application of local regulations are still issues for the majority of African countries, especially Morocco [5].

Facing local challenges, developing countries tend to create a BSAT that is appropriate to local needs [9]. ESTIDAMA, as an example of a local BSAT in the UAE, is tolerant towards renewable energy and water reduction in comparison to the exigencies of LEED and BREEAM [10]. This tolerance is reflected in the weighting system and points attribution that reflect the local tolerances. The presence of the national BSAT does not change the need for further studies that target its shortcomings in other respects, such as heritage buildings’ assessment [11,12]. In other cases, countries tend to adapt existing international BSATs to their region, such as VERDE adapting SBTool to the Spanish context [13], or Green Star South Africa’s adaptation from Australia [14]. Adaptation of an international SBAT or the development of a national one requires the involvement of local experts using multi-criteria decision-making (MCDM) tools [15].

The African continent has few BSATs developed locally, such as the Ethiopian tool directed to developing countries [8,16]. This uses the FAHP method to collect the weight from experts. It contributes 15% to sustainable management and 14% to waste and pollution as well as cost and economy. Another BSAT was developed for Sub-Saharan countries using direct weighting from expert surveys and interviews [4]. It allocates 29% to sustainable construction practices, 17% to indoor environmental quality, and 13% to energy. The challenge of these studies is the completeness of the weighting process using local experts. The lack of knowledge about BSATs among architects and engineers can hinder the process or prolong it [17]. In the case of the MENA region, studies in Saudi Arabia [6] and Oman [7] have used the Delphi and AHP methods. Oman’s local certification attributes 12% to indoor environmental quality and 10% to critical water resources; in the same way, Saudi Arabia’s system gives importance to water efficiency, energy, and indoor environmental quality. Overall, there are weight differences between local systems, as they reflect the local challenges. Even with the similarities between Moroccan conditions and MENA countries as well as the African continent, some aspects reflect local construction, regional climate conditions, and local policies that need to be addressed in a local sustainability assessment framework [5,18]. Hence, there is a need for a clear methodology adopted in the Moroccan context that prioritizes its local policies and needs.

To date, Morocco does not have a dedicated building sustainability assessment tool. Existing international frameworks such as LEED, BREEAM, or DGNB are not fully suited to the Moroccan context, as they give limited attention to local challenges such as water scarcity, informal urbanization, cultural practices, and inadequate waste infrastructure [5]. This study, therefore, introduces the first Moroccan BSAT, developed through expert consensus using the Fuzzy Delphi method. The originality of this research lies in its adaptation of proven international structures to Moroccan priorities, while ensuring local validity through expert elicitation. In doing so, it not only fills a national gap but also contributes to the broader discussion on tailoring sustainability assessment frameworks for developing countries.

This study develops a local grading system for Moroccan dwellings using Moroccan experts. It establishes a hierarchy for lists of categories, indicators, and sub-indicators gathered across existing BSATs and the prior literature. This study aims to address the gap between international certifications’ exigencies and African housing conditions. It puts together a simplified system that focuses on the national goals for construction. This paper is divided into five major sections: The first part is an introduction to the problem of the subject and explains the need for local BSATs. The second part is a literature review of the previous studies, discussing different local BSATs as well as the methods to develop a BSAT. The third part describes the methodology followed in this research. The fourth part is the presentation of the framework and the discussion of the results, as well as benchmarking the framework with international and local BSATs. The final part is the conclusion, presenting the main challenges facing local BSATs in Morocco.

2. Literature Review

The development of local BSATs requires gathering local experts’ opinions on the subject. Multi-criteria decision-making (MCDM) methodologies are used following several steps: indicator identification, categorization, weighting, and normalization of values to obtain a score [15]. Various MCDM methodologies are identified in the literature, such as Delphi, Exploratory Factor Analysis (EFA), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and the Analytic Hierarchy Process (AHP). Delphi is used to identify the hierarchy among categories, indicators, and sub-indicators [6,19]. The AHP is chosen for accurate weighting, as it proposes a pairwise assessment [20]. Various studies combine both methodologies for accurate weighting. Fuzzy methods are adopted to provide more accuracy and greater reasoning [21,22].

Expert surveys and interviews provide useful practical insights but are often affected by subjective bias and limited generalizability (

Table 1. Strengths and limitations of multi-criteria decision-making methods used in sustainability assessment.

Methods	Context	Area	Addressed Problems	Sources	Strength	Limitation
Expert Survey and Interview	United Kingdom	Sustainable Building	Sustainability assessment framework for housing regeneration	[24]	-Provides practical insights from stakeholders	-Subject to bias and limited generalizability
Delphi	Malaysia	Building Engineering	Assessment schemes for use in non-domestic buildings for refurbishment	[17]	-Achieves expert consensus systematically -Experts’ input	-Time-consuming -Dependent on experts
	Saudi Arabia	Sustainable Building	A scheme for sustainable building assessment	[6]
Exploratory Factor Analysis	UK	Building Engineering	Potential impediments to sustainable structural retrofit	[25]	-Identifies latent variables from data	-Requires large, high-quality datasets
Technique for Order Preference by Similarity to Ideal Solution (TOPSIS)	Spain	Building Engineering	Framework of renovation for residential buildings	[26]	-Ranks alternatives clearly and efficiently -Effective in multi-criteria decisions	-Sensitive to weight and scale choices -May overlook stakeholder nuances
	China	Building Engineering	Renovation of green building scheme	[27]
Analytic Hierarchy Process (AHP)	Italy	Building Engineering	Seismic retrofitting scenarios for a one-story building	[28]	-Simple and structured comparison method -Breaks down complex decisions hierarchically	-Inconsistencies in judgments can affect output -Becomes unwieldy with many criteria
	India	Urbanism	Assess the regional level of sustainability	[20]
Fuzzy AHP	Ethiopia	Building Sustainability	Building a sustainability assessment system (BSAS) for the least developed countries	[8]	-Handles uncertainty in decision-making	-Requires advanced expertise and interpretation

) [23]. The Delphi method is widely used to develop structured expert consensus, yet it is slow and depends heavily on the availability of experts. Exploratory Factor Analysis effectively uncovers hidden patterns and variables but requires large, high-quality datasets to ensure accuracy. Multi-criteria decision-making tools like TOPSIS offer quick and clear rankings of options but can be sensitive to weight assignments and might miss qualitative stakeholder perspectives. The AHP is valued for its systematic approach to complex decisions, although its reliability may decline as the number of criteria grows, due to possible inconsistencies. The Fuzzy AHP builds on the AHP by including uncertainty, enhancing decision robustness in ambiguous situations, but it requires advanced technical understanding. Overall, the table highlights the trade-offs among qualitative insights, computational complexity, and adaptability when choosing methods for sustainability assessment frameworks.

A review of leading international sustainability assessment tools, including BREEAM [29], LEED [30], DGNB [31], VERDE [32], WELL [33], and ESTIDAMA [3], served as the foundation for structuring the BSAT hierarchy proposed in this study. These frameworks consistently emphasize a core set of categories, which informed the selection of the five main domains in the BSAT: site, resources, quality of life, waste and pollution, and innovation. The “Site” category is widely addressed in systems such as LEED, BREEAM, and ESTIDAMA, underscoring issues of land use, heritage conservation, and transport integration, which are particularly relevant in Morocco due to rapid urbanization. The “Resources” category, comprising energy, water, and materials, is a central component across all reviewed tools, reflecting global concerns around efficiency and scarcity, which are especially pressing in the Moroccan context. “Quality of Life” draws on WELL’s occupant-centered focus and the user comfort indicators present in DGNB and BREEAM, emphasizing thermal, acoustic, and daylight performance. “Waste and Pollution” are prioritized in LEED, DGNB, and ESTIDAMA, aligning with Morocco’s urgent need to strengthen its waste infrastructure and pollution management. “Innovation,” recognized as a bonus or credit category in LEED and ESTIDAMA, was included to highlight context-specific, forward-thinking strategies such as passive cooling and digitalization. This hierarchical structure thus adapts proven international practice to national priorities, ensuring both global coherence and local relevance.

Building on this structural foundation, the next critical step in developing a robust BSAT is the identification and validation of an updated and context-sensitive list of indicators. Most sustainability assessment tools adopt a hierarchical framework comprising categories, indicators, and sub-indicators, typically aligned with the environmental, economic, and social pillars of sustainability. Certification tools used to give the environmental pillar more importance [15]. The presence of indicators from the three pillars serves as a reliability test for building performance [34]. Categories can vary according to local policies and national perspectives [15]. The most cited indicators in the literature are impact assessment, resources, waste, output flaws [35], materials, energy, and indoor environment quality [15]. There is no definite list or hierarchy for indicators and sub-indicators. Yang et al. cited 83 sub-indicators for energy indicators gathered in the literature and SBATs using a participatory expert survey [36]. Piparsania and Kalita followed the same method to determine social and cultural building assessment indicators [37].

3. Methodology

This study seeks to develop a BSAT model appropriate to the Moroccan context using the F-Delphi method. The experts helped develop a hierarchy list including categories, criteria, and sub-criteria, using several rounds of surveys. The developed Moroccan BSAT was compared to five local BSATs in the existing literature used in the African context and the MENA region [4,6,7,8], to ensure its validity and alignment with the regional context.

There are several methodologies in the literature that have been used to develop a sustainability assessment framework for buildings. To find the appropriate methodology, face-to-face interviews and pre-survey tests were established in the School of Architecture, Planning, and Design, with academic professionals permitted to test the methodologies as well as the answer rate, helping to distinguish which MCDM methodologies can be applied to the Moroccan context. The pre-tests, answered by 14 different professors and doctoral students, showcased the following:

-

Experts find difficulties in rating pairwise questions; this hinders the application of the AHP method.

-

Low response rate for surveys exceeding 40 questions: The list of categories, indicators, and sub-indicators proposed in the surveys cannot exceed a certain amount, so as to limit the number of questions.

-

Preference towards online systems rather than face-to-face interviews: The response rate is higher in online surveys.

This preliminary study helped shape the survey questions as well as the choice of the Delphi method as an assessment methodology for this case.

3.1. F-Delphi

The Delphi methodology is an MCDM approach that uses expert panel knowledge to obtain an objective opinion on an issue [38,39]. It is effective to obtain knowledge on issues using local experts from different areas [40]. The method consists of having a group of experts (expert panels) and obtaining their opinions about the issue in several rounds. This helps converge these opinions into statistical results [41]. The method has three pillars: anonymous response, iteration and controlled feedback, and statistical group response [6]. The anonymous pillar ensures the objectivity of the experts’ opinions and that they do not influence each other’s responses. The iteration ensures multiple rounds, with post-analysis results presented to the experts after each round. This operation helps in reaching a common ground among the experts. Statistical responses quantify the experts’ opinions using a scale. The results measure the median tendencies and the dispersion level [17].

Fuzzy theory was first developed to ensure the adequacy between the human scale nuances and numerical values [42]. Fuzzy theory adds adequacy to MCDM methodologies and is widely used for subjects regarding sustainability and refining the number of criteria [43]. The uncertainty of experts’ evaluation between scale numbers is reflected by a triangular fuzzy number (TFN). Its function is defined by a triplet of real numbers (a, b, c), and a ≤ b ≤ c, where a is the lowest value that b can take, and c is the highest value [40,44,45]. The triangle membership is defined as follows (Equation (1)):

$${\mathrm{\mu }}_{\mathrm{N}\left(\mathrm{x}\right)}=\left\{\begin{array}{c}0, \mathrm{x} < \mathrm{a} \\ {\displaystyle \frac{(\mathrm{x}-\mathrm{a})}{(\mathrm{b}-\mathrm{a})}} , \mathrm{a} \le \mathrm{x} \le \mathrm{b}\\ {\displaystyle \frac{\left(\mathrm{c}-\mathrm{x}\right)}{\left(\mathrm{c}-\mathrm{b}\right)}} , \mathrm{b} \le \mathrm{x} \le \mathrm{c} \\ 0, \mathrm{x} > \mathrm{c} \end{array}\right.$$

(1)

where a is the lower bound, b is the peak (where membership = 1, meaning “fully belongs” to the fuzzy set), c is the upper bound (where the function starts decreasing), and μN(x) is the membership degree of x (how much x belongs to the fuzzy set).

$$\tilde{N}1(+)\tilde{N}2=(a1,b1, c1)(+)(a2,b2,c2)=(a1+a2,b1+b2,c1+c2)$$

(2)

$$\tilde{N}1(-)\tilde{N}2=(a1,b1, c1)(-)(a2,b2,c2)=(a1-a2,b1-b2,c1-c2)$$

(3)

$$\tilde{N}1(\times )\tilde{N}2=(a1,b1, c1)(\times )(a2,b2,c2)=(a1a2,b1b2,c1c2)$$

(4)

$$\tilde{\mathrm{N}}1(÷)\tilde{\mathrm{N}}2=(\mathrm{a}1,\mathrm{b}1,\mathrm{c}1)(÷)(\mathrm{a}2,\mathrm{b}2,\mathrm{c}2)=({\displaystyle \frac{\mathrm{a}1}{\mathrm{a}2}},{\displaystyle \frac{\mathrm{b}1}{\mathrm{b}2}},{\displaystyle \frac{\mathrm{c}1}{\mathrm{c}2}})$$

(5)

The BSAT developed using Delphi and Fuzzy Delphi gives different perspectives on the strengths and weaknesses of this method. The steps followed for this study are as follows:

Step 1: Identification of key parameters to assess buildings’ sustainability from the literature; a list of set categories (C₁, C₂…), indicators (I₁, I₂…), and sub-indicators (S₁, S₂…).

Step 2: Preparation of a questionnaire for the experts containing the list for BSA.

Step 3: The mean values reflecting the weighting of categories, indicators, and sub-indicators are calculated after aggregation and defuzzification.

3.1.1. Category Identification

The list of indicators found in existing BSATs, such as LEED, BREEAM, ESTIDAMA, HQE, and WELL, was added to the indicator list extracted from the literature and combined within 5 main categories. These categories represent the Moroccan future perspective: site, life quality, resources, waste and pollution, and innovation (

Table 2. Gathered initial main list of BSA categories, indicators, and sub-indicators (Round 1).

Category	Indicator	Sub-Indicator	Description
[C1] Site	[I1] Environmental Impact Assessment	[S1] Biodiversity assessment	Evaluation of the variety of plant and animal species in the area and the building’s impact on them.
		[S2] Pollution assessment of the site	Analysis of air, water, and soil contamination levels of the site.
		[S3] Flood risk design	Measures to mitigate flood risks through effective design.
	[I2] Site Selection	[S4] Historical site conservation	Measures to protect and preserve culturally or historically significant sites.
		[S5] Fertile land, contaminated land	Assessment of soil quality for agricultural use and identification of polluted areas.
		[S6] Orientation	Evaluation of site orientation for optimal environmental and energy performance.
		[S7] Land use, waste land reuse	Planning for efficient land use and repurposing of abandoned or unused sites.
	[I3] Construction	[S8] Waste management (transport, CO2 pollution)	Management of construction waste and reduction in carbon emissions.
		[S9] Quality assessment (foundation, earthquake regulation)	Evaluation of structural stability and compliance with seismic regulations.
		[S10] Maintenance assessment (service years, replacement, repainting, etc.)	Estimation of building lifespan and prediction of maintenance needs over time.
		[S11] Cost assessment (site, building MAD)	An analysis of financial costs for site preparation and building construction, life-cycle cost.
		[S12] Usage of existing infrastructure	Maximize the use of available infrastructure to minimize new construction.
	[I4] Urban Harmony	[S13] Compliance with urban standards (shape, color) with regulations (RTCM, etc.)	Adherence to urban design guidelines and national regulatory codes.
		[S14] Compliance with local forms and practices	Alignment with local architectural styles and cultural practices.
		[S15] Architect commissioning	Hiring qualified architects for project design and planning.
		[S16] Landscape design	Planning and designing outdoor spaces to enhance aesthetics and usability.
	[I5] Transportation	[S17] Public transport (stops), alternative transport	Integration of public transit systems and promotion of alternative transport options.
		[S18] Road safety	Measures to ensure the safety of road users, including pedestrians.
		[S19] Pedestrian roads (walkability, signage)	Design of pedestrian-friendly pathways with clear signage.
		[S20] Parking spots	Adequate provision of parking spaces for vehicles.
		[S21] Amenities (distances to mosques, souks, schools, hospitals, etc.)	Proximity to essential services and community facilities.
[C2] Quality of Life	[I6] Occupant Education Level	[S22] Household education level (high school, bachelor)	Assessment of education levels within households.
		[S23] Community awareness (local sustainable practices)	Evaluation of community engagement in sustainable practices.
		[S24] Conformity to local regulations (RTCM)	Compliance with local laws and building regulations.
	[I7] Economic Comfort	[S25] Household management cost (rent, mortgage, bills)	Analysis of financial burdens related to housing and utilities.
		[S26] Yearly income (above/below average)	Comparison of household income to national or regional averages.
	[I8] Occupants’ Well-Being (Health)	[S27] Interior circulation, programs, movement encouragement	Design features and programs promoting physical activity and mobility.
		[S28] Diets, health conditions	Consideration of dietary habits and prevalent health issues in the design.
	[I9] Indoor Comfort	[S29] Thermal comfort (temp, PMV)	Evaluation of indoor temperature and thermal comfort for occupants.
		[S30] Lighting (daylight, interior lighting, lux)	Assessment of natural and artificial lighting quality.
		[S31] Acoustics (db)	Measurement of sound levels to ensure minimal noise disturbance.
		[S32] Air quality (PPM, CO2, etc.)	Analysis of indoor air pollutants and ventilation efficiency.
	[I10] Outdoor Comfort	[S33] Safety (overlooking facades, safe parks courtyard, emergency services, etc.)	Safety measures for outdoor spaces, including visibility and emergency access.
		[S34] Privacy conservation in design	Architectural designs that preserve occupant privacy.
		[S35] Accessibility of the building	Features that ensure easy access for all individuals, including those with disabilities.
		[S36] Lighting (neighborhood lighting, etc.)	Adequate outdoor lighting for safety and aesthetics.
		[S37] Fitness amenities, children’s playgrounds	Provision of recreational areas for fitness and children’s play.
[C3] Resources	[I11] Energy	[S38] Primary operational energy (kWh)	Measurement of energy consumption during building operations.
		[S39] Conformity to local regulations (RTCM), envelope conformity	Compliance with energy-related local regulations, (thermal Moroccan regulation baseline).
		[S40] Renewable energy integration (PV), wind energy (kWh)	Use of renewable energy sources such as solar and wind power.
	[I12] Water	[S41] Household water usage (m3)	Monitoring and managing water consumption in households.
		[S42] Rainwater management (design pathways for freshwater conservation and reuse)	Systems for collecting and reusing rainwater to conserve resources.
		[S43] Water source	Evaluation of water supply sources for sustainability.
		[S44] Water quality	Assessment of water purity and safety for use.
	[I13] Materials	[S45] Material quality (robustness, sustainability)	Selection of durable and eco-friendly construction materials.
		[S46] Safety (no hazardous materials, emissions while used)	Use of materials that do not release harmful substances during use.
		[S47] Reusability (EOL)	Design of materials for reuse or recycling at the end of their life cycle.
[C4] Waste and Pollution	[I14] Buildings’ Pollution	[S48] Life-cycle assessment (GWP, AP, EP, etc.)	An analysis of environmental impacts throughout the building’s life cycle.
		[S49] Waste management (waste usage)	Systems for managing and reducing waste generation.
		[S50] Sewage system management	Processes to treat and manage wastewater effectively.
[C5] Innovation	[I15] Building Design Innovation	[S51] Integration of passive solutions, awards	Incorporation of passive design strategies and recognition for innovation.
		[S52] New technologies integrated (quality-of-life improvement)	Adoption of advanced technologies to enhance quality of life.
	[I16] Exemplary Overall Performance	[S53] Baseline conformity	Adherence to standard benchmarks for performance.
		[S54] Minimal resource usage	Strategies to minimize the use of natural and human resources.

). The following methodological rules governed the inclusion and organization of indicators and sub-indicators:

1. Consensus-Based Selection: Any indicator found in at least two internationally recognized sustainability assessment systems, such as BREEAM, LEED, DGNB, VERDE, WELL, or ESTIDAMA, was retained in the BSAT framework to ensure consistency with global standards and reflect international consensus on core sustainability priorities.

2. Indicator Mapping: Sub-indicators with conceptual similarities but derived from differently named categories across tools were grouped under a common indicator in the BSAT structure. For example, energy-related sub-indicators from both DGNB and LEED were consolidated under a single “Energy” indicator, ensuring semantic alignment and thematic coherence.

3. Contextual Addition: Where an indicator and its sub-indicators were not explicitly repeated across tools (and therefore not retained under Rule 1 or 2) but were deemed contextually significant for Morocco, due to climatic, regulatory, or socio-economic factors, they were included as standalone indicators. This step ensured that the BSAT hierarchy addressed local needs while maintaining methodological rigor.

3.1.2. Appointment of a Panel of Experts

There is no fixed number of experts in MCDM methods in general and in the case of the Delphi method specifically [46]. If the number of experts is too small, the results may be subject to bias. Conversely, a larger number of experts increases the risk of a low response rate. Therefore, it is generally recommended to maintain the number of experts between 3 and 50 to balance these factors [17,40]. In this study, 14 experts answered the survey in Round 1, and 11 in Round 2.

The selection of experts followed the criteria of advanced degrees and years of expertise [47]. Experts were recruited through professional networks, academic partnerships, and invitations sent to relevant ministries and professional associations. A total of 28 experts were invited, of whom 14 agreed to participate (response rate of 50% in Round 1 and 39% in Round 2). Eligibility criteria included holding at least a master’s degree or equivalent professional qualification, a minimum of two years of professional experience in the fields of architecture, engineering, urbanism, or environmental policy, and active engagement with Moroccan construction or sustainability practice. The final panel included participants with between 2 and 30 years of practice (median: 15 years), ensuring both early-career and senior expertise (Figure 1). No financial incentives were provided; participation was entirely voluntary. The panel composition was 70% from industry and professional practice (civil servants, private companies, independent architects, or certification bodies) and 30% from academia (

Table 3. Experts’ background fields.

Professional Field	Experts Number	Academia	Industry Stakeholders
Architecture/Urban Planning	4	0	4
Building Economy	2	2	0
Civil Engineering	4	1	3
Environment	1	0	1

). Geographically, most of the experts were concentrated in urban centers such as Rabat and Casablanca, mainly targeting the cities.

3.1.3. Survey Development

The survey was designed in four main sections: The first part collected the demographic data of the experts, revealing their educational field and years of expertise. The second part was for the categories section (C1, C2…), the third was for indicators (I1, I2…), and the last part was for sub-indicators (S1, S2…). The survey allowed the experts to rate each hierarchy element and provided space to add an explanation, along with more elements that were implemented in further rounds.

The experts were presented with the list of categories, indicators, and sub-indicators to evaluate their importance and impact in the Moroccan context. Then, their evaluation was translated into quantitative scores, as explained in Section 3.1. The experts gave their answers, choosing from linguistic values varying from unimportant to very highly important (

Table 4. Linguistic scale for Fuzzy Delphi approach.

Linguistic Variable	Description	Corresponding TFN
Inadequate (Very Unimportant)	No need; the category/indicator/sub-indicator is not important to assess Moroccan building sustainability	(0, 0, 0.25)
Not Important	Minor importance for assessment	(0, 0.25, 0.5)
Important	Medium importance; it can impact the assessment	(0.25, 0.5, 0.75)
Highly Important	Important for the assessment	(0.5, 0.75, 1)
Very Highly Important	Indispensable to assess Moroccan buildings’ sustainability	(0.75, 1, 1)

). The mean results were calculated and presented again in the following round. This study conducted two rounds of Delphi surveys. Each round’s results were analyzed and represented by the experts anonymously. Due to the restriction of gathering all of the different experts, the process was carried out entirely by e-mail. This process allowed the experts to review the results of the first rounds before assessing them again until there was consensus.

3.1.4. Aggregation, Defuzzification, and Consensus Checking

The experts’ responses were translated using the appropriate linguistic scale explained in Table 4. A 5-point linguistic scale was selected for the Delphi survey to allow experts from diverse backgrounds to easily evaluate the importance of each sub-indicator. Linguistic scales are recommended in Delphi studies where items are subjective and complex, as they reduce ambiguity and cognitive load. Each verbal category was assigned a numeric value to facilitate statistical analysis and determination of consensus, consistent with previous studies in urban sustainability and building assessment [40,41]. The scale chosen was between 0 and 1, using TFN standard fuzzy triangular membership functions. The scale was distributed into five points, as explained in Table 4. The collected scores were then used to calculate the aggregated impact or the weight of categories (C), indicators (I), and sub-indicators (S). They were then translated into TFN format. The aggregation was then calculated as follows:

$$\tilde{\mathrm{M}}=\left.\left({\displaystyle \frac{1}{\mathrm{n}}}{\sum }_{\mathrm{n}=1}^{\mathrm{n}}\mathrm{a}\mathrm{i},{\displaystyle \frac{1}{\mathrm{n}}}{\sum }_{\mathrm{n}=1}^{\mathrm{n}}\mathrm{b}\mathrm{i},{\displaystyle \frac{1}{\mathrm{n}}}{\sum }_{\mathrm{n}=1}^{\mathrm{n}}\mathrm{c}\mathrm{i}\right.\right)$$

(6)

where a, b, and c are the lower, middle, and upper values of TFN members for each expert n, respectively. Then, the defuzzification was calculated using the center of gravity (COG) as follows:

$$\mathrm{D}={\displaystyle \frac{\mathrm{a}+4\mathrm{b}+\mathrm{c}}{6}}$$

(7)

Consensus among experts was assessed using the dispersion threshold approach, where an item was considered stable when the difference between consecutive rounds was ≤0.2 [48].

3.2. The Case Study: Moroccan Example

The Moroccan construction sector accounts for up to 33% of the state’s energy consumption [49]. However, no local certification for buildings’ sustainability assessment (BSAT) is used. Morocco’s fast urbanization and construction present an opportunity for energy savings, as 42.29% of the buildings are less than 20 years old [50]. The building sector in Morocco faces many challenges. For example, 13.7% of buildings are outside of the water grid. Only 65% have access to sewer systems, and 53.9% of household waste is not managed [50]. The social differences between rural and urban areas are still persistent. Public transportation is limited [51]. All of these circumstances can make the integration of international BSATs challenging. The following proposed framework can provide a weighting and baseline for indicators without a pre-determined baseline.

4. Results and Discussion

This framework addresses the assessment of residential buildings, taking into account the Moroccan context. It is designed to evaluate residential buildings in the usage phase. It consists of the following hierarchy, with the five main categories achieving consensus (C1, C2, C3, C4, and C5) (

Table 5. The consensus checking, defuzzification, and normalization of the main categories. Consensus was achieved when the absolute difference between expert defuzzified scores was ≤0.2 (Appendix B).

Categories	Consensus	Defuzzification	Normalization
Site	Consensus achieved	0.723	0.163
Quality of Life	Consensus achieved	0.712	0.160
Resources	Consensus achieved	0.754	0.170
Waste and Pollution	Consensus achieved	0.799	0.180
Innovation	Consensus achieved	0.667	0.150
Adaptability and Resilience	Consensus achieved	0.784	0.177

). The first round’s result adds the sixth category, adaptability and resilience (C6) (Appendix C). This additional category aligns with international consensus in recent years for resilient spaces [52,53]. The waste and pollution category has the highest weight of 0.8. In contrast, innovation has the lowest weight, at 0.67. Adaptability and resilience, added in the second round, achieved a weight of 0.78. There is also a general consensus regarding the objective of the building assessment framework: 90% of the experts stated that the objective of BSATs is building assessment, and 10% stated it to be building assessment and occupants’ well-being, while none suggested targeting only the occupants’ well-being. The survey was designed with 39 sub-indicators for “building only”, such as primary energy and landscape design. The remaining 25 sub-indicators were for occupants, such as community awareness and thermal comfort. According to the weighting results, sub-indicators related to buildings and sub-indicators related to occupants have a similar weighting, with mean values of around 0.806.

All experts answered positively to the following question: Do you think Morocco needs to evaluate the impact of its construction (environmental, economic, social)? The final list of sub-indicators contained 28 sub-indicators related to the environmental pillar, 11 sub-indicators related to the economic pillar, and 27 sub-indicators related to the social pillar. The average weight related to each pillar was around 0.80, with the social pillar ranking as most important, followed by the environmental pillar.

4.1. Indicators’ Weighting

The weighting of the indicators followed the ranking of the categories. Waste and pollution indicators, such as waste management and wastewater management, had the highest weight, with 0.958 (Figure 2). Water and energy indicators also ranked higher, with 0.902 and 0.886, respectively. In contrast, site indicators, such as site selection with 0.754 and transport with 0.727, ranked the lowest. Quality-of-life indicators such as economic comfort had the least weight (0.667). The occupants’ education level received no consensus as an indicator in the two rounds.

4.2. Sub-Indicators’ Weighting

Waste and pollution sub-indicators (S48, S49, S50) had the most weight. Sewage system management received the highest weight, with a normalized value of 0.053, indicating strong agreement among experts or stakeholders regarding its significance within the domain of waste and pollution. Waste management also received a high score (0.049), suggesting a shared recognition of its critical role in environmental performance. In contrast, life-cycle assessment registered a relatively lower value of 0.043, which may reflect either a lower perceived importance or a reduced level of consensus regarding its integration in current practices (Figure 3). The results suggest that operational aspects of waste and pollution, particularly those directly related to infrastructure and immediate environmental impact, are prioritized in sustainability assessments. Conversely, life-cycle assessment, which entails a more comprehensive and long-term evaluation approach, is not yet uniformly valued across stakeholders.

For the category of adaptability and resilience, the highest-scoring sub-indicators included capacity of rainwater collection and storage for non-potable uses, access to critical infrastructure during crisis, and stormwater retention capacity on site, with normalized weights between 0.052 and 0.050. These components reflect a strong emphasis on infrastructure readiness and water resilience. Moderate scores were observed for use of vegetation to improve microclimate and for heat island effect mitigation (0.051). This indicates recognition of nature-based solutions in climate adaptation. The lowest weighting was assigned to capacity for post-disaster use, at 0.048 (Figure 3). This may signal a gap in long-term recovery planning or limited integration of flexible post-crisis infrastructure. The data suggest that while immediate and preventive resilience measures are prioritized, post-disaster adaptability remains under-emphasized.

The resources category also scored highly. High-performing sub-indicators included rainwater management, water source, water quality, and household water usage, all scoring above 0.046.

This highlights a strong prioritization of water-related sustainability, reflecting increasing awareness of water scarcity and circular usage in Morocco. Moderate scores were seen for reusability, safety in usage stage, renewable energy integration, and envelope conformity. These results suggest a balanced approach to energy and material sustainability. Lower scores were attributed to electricity network coverage (0.044) and material quality (0.046), suggesting room for improvement in energy infrastructure reliability and construction inputs (Figure 3). Overall, the results indicate a comprehensive resource strategy with notable strength in water sustainability.

For the site category sub-indicators, pedestrian roads, amenities, road safety, and public transport ranked the highest, with scores exceeding 0.49. The results suggest the importance of infrastructure and transport for the national experts. Maintenance, quality assessment, site waste management, fertile land contamination, compliance to urban standards, compliance to local forms, commissioning, and cost assessment ranked moderately. Biodiversity assessment and site orientation ranked the lowest, with 0.040. Land use and waste land reuse failed to achieve consensus, with a normalized score of 0.039. In general, national priorities reflect the importance of waste and infrastructure in terms of site category, while socio-economic factors are given second priority.

Quality of life sub-indicators related to occupants, such as community awareness, conformity to local regulations, lighting comfort (interior and exterior), and fitness amenities/children’s playgrounds—scored highly (0.050), indicating that the experts prioritize livability, social integration, and adherence to standards that enhance daily life experience. In contrast, intermediate scores were obtained for hedonic site value, neighborhood safety, privacy conservation, interior circulation, and dieting, which all scored between 0.044 and 0.046. Lower scores for household management cost and yearly income (0.042 and 0.044, respectively) reflect a relative de-emphasis on purely economic criteria in the context of built environment interventions.

The innovation category was the lowest-scoring category. The sub-indicators regarding construction digitalization, baseline conformity, and new technologies integrated ranked between 0.044 and 0.046. The lowest rank was attributed to minimal resource usage and passive solution integration, at 0.040 (Figure 3). This reflects the systemic barriers to the implementation of innovation indicators in the local context.

4.3. Discussion

Overall, the findings point to a sustainability framework in Morocco that strongly values operational functionality, infrastructure reliability, and water management, while still evolving in its adoption of long-term, systemic, and innovation-driven strategies. This finding aligns with the national priorities, especially given the local contextual challenges surrounding waste, pollution, and infrastructure [54]. The high weight assigned to social indicators reflects Morocco’s national development priorities, which focus on social housing quality, safety, and accessibility [54]. Similarly, the prioritization of sewage system management and wastewater reuse directly aligns with Morocco’s 2020–2050 National Water Strategy, emphasizing sanitation and adaptation to water scarcity [55]. Public infrastructure indicators, including transport, amenities, and pedestrian access, further correspond with urban mobility policies and green city initiatives in Rabat and Casablanca [56]. These contextual links clarify why national experts emphasized these sub-indicators and demonstrate how the MBSAT supports Morocco’s broader policy objectives.

At the same time, the relatively low scores for life-cycle assessment (LCA) and innovation-oriented sub-indicators (digitalization, passive solutions, and minimal resource usage) highlight ongoing systemic challenges. Sector studies confirm that Morocco’s building sector has been slow to integrate innovative practices such as lean construction and digital tools [57], while the implementation of LCA frameworks remains limited by regulatory and technical gaps [58]. Broader reviews of urban sustainability similarly note that Moroccan policy efforts prioritize immediate challenges such as waste, water, and infrastructure, while advanced practices related to innovation and LCA remain underdeveloped [59]. These results reinforce this study’s finding that the relatively low prioritization of innovation and LCA in the framework reflects structural sectoral constraints.

A comparative study of the established Moroccan building sustainability assessment tool (MBSAT) and the established local BSATs showcases the importance of local assessment (Appendix D). The analysis includes indicator weightings across BSATs developed for the African continent and the Middle East region: Saudi Arabia [6], Oman [7], Sub-Saharan Africa [4], Ethiopia [8], and Morocco (the current study). The indicators have been normalized to a common scale (0 to 1) to allow direct comparison. The aim is to position the newly developed MBSAT against established regional frameworks and identify convergences and divergences in indicator prioritization. In general, water, energy, and materials are relevant across all frameworks, especially for the MENA region-related BSATs (Figure 4). The site indicators show moderate weighting in most BSATs, with Ethiopia assigning relatively high values (0.0663), reflecting an awareness of ecological and geographic sensitivity. In contrast, urban planning is explicitly addressed only in the Moroccan (0.0468) and Omani (0.0865) BSATs, reflecting the integration of spatial coherence into sustainability evaluation in more regulated urban contexts.

The regional BSATs agree on the importance of resource indicators in accordance with the challenges of the context. The MBSAT assigns the highest weight to water (Figure 4). The Omani BSAT gives a higher ranking to energy efficiency, while material efficiency is given more attention in the Ethiopian and Sub-Saharan African BSATs.

For the quality-of-life category, as opposed to the MBSAT results, the Ethiopian BSAT strongly emphasizes economic comfort (0.136), assigning it a higher value than any other system. The results reflect a noticeable agreement that affordability and household economics are less central to the performance evaluation for Moroccan experts. The absence of this indicator in the other MENA BSATs suggests shared values. Notably, health and well-being are largely absent from most frameworks, with only the Moroccan BSAT explicitly including this domain (0.0521). This gap indicates a potential underrepresentation of human-centered metrics in sustainability assessments in developing countries.

Despite the importance of emissions and environmental toxicity in global frameworks, their weight is limited for most of the studied local BSATs, while waste management is highly weighted across African and Middle-Eastern BSATs.

The MBSAT gives relatively lower weights for thermal and environmental resilience, in contrast to the Ethiopian BSAT and Sub-Saharan BSAT, which give higher weights (0.150 and 0.107, respectively) for environmental resilience.

The innovation category is inconsistently addressed across BSATs. Only Ethiopia (0.1), Oman (0.0801), and Morocco (0.0521) assign measurable weights to innovation in building design, while the Sub-Saharan and Saudi frameworks omit this dimension.

Overall, the Moroccan BSAT demonstrates a balanced weighting structure with a slightly higher emphasis on environmental performance and technical infrastructure—such as waste, water, and energy—than on socio-economic or adaptive capacity. In contrast, the Ethiopian and Sub-Saharan frameworks tend to integrate the resilience and economic dimensions more strongly, likely responding to acute vulnerabilities in their national contexts. The developed framework offers a balanced weighting and appropriate indicators that align with similar local BSATs in the same region.

Applicability and Limitations

This study develops a Moroccan building sustainability assessment tool (BSAT) tailored to urban residential contexts, offering policymakers and practitioners a framework aligned with national priorities such as waste management, water resilience, and quality of life. By combining international best practices with locally relevant sub-indicators, the tool provides a practical basis for certification schemes and urban planning policies. However, some limitations remain. The panel was concentrated in major cities, which limits generalizability to rural areas. In addition, the framework is yet to be tested on actual housing projects. To move from framework development to practical application, it is essential to establish clear scoring implementation paths, defining thresholds, crediting systems, and rating levels, and to conduct pilot applications on real residential projects. Such pilots would validate usability, support calibration of weights and thresholds, and offer municipalities and developers a roadmap for operational adoption. Future work should pilot the framework in practice and update the indicators over time to reflect evolving Moroccan priorities.

5. Conclusions

This study developed and validated a local BSAT using Morocco as a case study. It used an F-Delphi process to structure a weighting system. The framework reached a consensus across six categories: site, resources, quality of life, waste and pollution, adaptability and resilience, and innovation. The established hierarchy of categories, indicators, and sub-indicators is the result of the second-round survey, reflecting the growing attention of the local experts to emerging challenges such as resilience and post-crisis functionality.

The framework balances building-related and occupant-related indicators, with comparable average weights, reinforcing the dual importance of environmental performance and user-centered livability. In terms of pillars, the social dimension is ranked the highest, followed by the environmental pillar, whereas the economic pillar is weighted less heavily. The results align with local policies and present challenges in terms of social and environmental issues. The waste and pollution category has the highest weight, underscoring a strong consensus on the importance of environmental impacts on the local context for developing countries. In contrast, innovation has the lowest score, indicating its lower urgency in a similar context. The MBSAT aligns with the existing African and Middle-Eastern local BSATs. It prioritizes water, energy, and material efficiency, consistent with resource-scarce and arid geographies. The witnessed divergence in innovation and economic indicators reflects Moroccan local strategies, as the experts’ weightings align with local challenges.

Ultimately, the Moroccan BSAT contributes to the growing body of localized sustainability assessment tools by offering a methodologically robust, consensus-driven framework tailored to national priorities. It provides a structured basis for promoting environmentally sound, socially integrated, and context-appropriate residential development. Future work should explore the dynamic integration of resilience and innovation, as well as field validation through case studies, to support more adaptive and forward-looking sustainability planning in Morocco and comparable regions.