Moroccan Public Buildings and the RTCM: Insights into Compliance, Energy Performance, and Regulation Improvement

Abstract

This study investigates the compliance of Moroccan public buildings with the thermal regulation (RTCM). It analysis public building envelope typology, the conformity and the impact of RTCM conformity on energy performance across the six climatic zones defined by the RTCM. The outcomes of this research may serve as a decision-support instrument by identifying areas where the thermal regulation is already validated and the potential impact that a public building could undergo by implementing these provisions. Additionally, this study can be viewed as a crucial analysis contributing to the enhancement of the existing regulation. The study emphasizes various extraneous stipulations present within the prevailing regulation. In this work, we have attempted to categorize these stipulations into two distinct groups: recommendations for refinement to be integrated into the regulatory framework, and essential measures to ensure successful implementation of the regulation in the realm of building energy efficiency.

1. Introduction

The building and construction sector accounts for over one-third of global final energy consumption and approximately 40% of total direct and indirect CO₂ emissions, as reported by the International Energy Agency [1]. It is ranked second globally in energy consumption, after transportation, with a significant portion allocated to air conditioning and heating. This substantial usage leads to increasingly high energy costs, prompting countries worldwide to seek comprehensive solutions to address these challenges. In developing countries, easy access to energy, coupled with the widespread use of energy-consuming appliances and the rapid expansion of building floor areas worldwide, has accelerated global energy resource consumption [2]. It is, therefore, imperative to use energy rationally and economically [3]. Optimizing the use of energy in buildings can thus lead to a reduction in the consumption of non-renewable energy and the emission of greenhouse gases [4]. Energy efficiency (EE) is deemed the primary pillar of the building revolution [5]. Analyses have shown that energy efficiency is possible on such a scale that it will become the “primary energy resource” in many countries. As a result, improving the energy performance of buildings has become a pillar of energy policies, especially in public buildings (BPs). Zhao et al. [6] stated that the phenomenon of high energy consumption and low energy efficiency of BPs is common, which means that there is a great potential for energy saving in BPs. Numerous nations worldwide have emphasized enhancing energy efficiency and using energy rationally and economically [7]. Sick et al. [8] showed that several countries, including Algeria, Egypt, Turkey, Syria, Lebanon, the Palestinian Territories, and Tunisia, have established thermal regulations for the building sector. Furthermore, countries such as Tunisia, Algeria, Egypt, and Turkey have mandated the application of these thermal regulations. In contrast, Jordan, Syria, and Lebanon have formulated thermal regulations that are currently in the process of being adopted.

In Morocco, the building sector is currently the second most energy-intensive economic sector; after the transport sector, it represents 33% of the country’s total energy consumption [9]. Within the framework of the national energy strategy, several actions have been initiated, including the Thermal Regulation of the Construction in Morocco (RTCM) through the Decree of Urbanism bearing the approval of the General Regulation of the Construction fixing the rules of the general energy performance of the construction and the introduction of the sheet of conformity among the documents required for obtaining authorization to build. However, public procurement remains at reduced energy efficiency [10]. The proof is that the Moroccan thermal regulation has remained since its publication in the official bulletin in 2014, modestly applied in the tertiary sector, including BPs. As a result, Morocco is working to make energy efficiency a national priority by reinforcing existing legislation, developing policies and standards for cost-effective energy efficiency, and moving quickly to adopt and implement the National Energy Efficiency Strategy for 2030 to meet the government’s 2030 targets, supported by adequate financial resources.

The objective of our study is twofold: to evaluate public buildings’ adherence to the Thermal Regulation of Buildings in Morocco (RTCM) and to quantify the potential benefits of RTCM compliance on these establishments. A comprehensive review of building envelope typologies across six climatic zones facilitates an examination of RTCM compliance’s influence on energy performance. The structure of this paper is as follows: Section 2 contains a review of relevant literature and prior studies. Section 3 outlines the methodology used in this research. The subsequent section delivers the study results and discusses these findings in the penultimate section. The paper concludes by emphasizing the critical insights derived from this investigation.

2. Literature Review

2.1. Policy Implications for Enhancing Energy Efficiency

As current trends, sharp demand growth, conflicts, and diplomatic concerns underline their increasing importance, international attention on energy issues is intensifying [11]. Within this global framework, the building sector contributes to about 40% of overall energy consumption, with heating, ventilation, and air conditioning systems being the primary users [12]. Particular attention has been given to non-residential buildings in Europe, including privately-owned offices, trading and gastronomic facilities, healthcare and educational buildings, industrial structures, and public buildings. These entities account for about a quarter of European buildings’ energy consumption [13]. Public buildings (PBs), such as offices, hotels, retail outlets, hospitals, and schools, have a high energy consumption intensity [14].

Within the European Union, enhancing energy efficiency (EE) in buildings has become a key element of energy. This policy development emerged in the 1970s and initially took the form of control instruments, building codes, information campaigns, and economic incentives [15]. The regulatory foundation was set with the introduction of the Energy Performance of Buildings Directive, which established minimum EE requirements for new and renovated buildings [16].

Germany has set ambitious energy efficiency targets, including an 80% reduction in building sector energy demand by 2050, alongside an interim objective to decrease heating demand by 20% by 2020 [17]. On the other hand, Italy’s municipalities have significantly contributed to implementing Building Energy Regulation Codes (BERC), which aim to reduce building energy consumption and foster environmentally friendly building practices [16]. The BERC has profoundly influenced various building sector stakeholders, including engineers, architects, local planners, and construction firms. Meanwhile, Spain’s building energy efficiency progress has been slower than other European nations. However, significant strides have been made with the latest version of the Technical Building Code, published via Royal Decree 732/2019, which earmarks energy conservation and thermal insulation as key elements of building energy efficiency [18].

In the United Kingdom (UK), measures to decrease energy consumption through building regulations were introduced in 1965, focusing primarily on efficient design. Over time, these regulations evolved to mitigate greenhouse gas emissions by progressively lowering the U-value for exposed walls from 1.7 W/m²K in 1965 to 0.35 W/m²K in 2002. These regulations necessitated enhancements in insulation thickness and restrictions on facade glazed areas, leading to perceived constraints on innovation in architectural design, construction materials, and control systems [19].

In Morocco, population growth and a substantial increase in electricity demand, at a rate of 6–8% per year, stress the energy supply [9]. The electricity sector has a high energy dependence, as more than 90% of its energy supply is imported, primarily as fossil fuels, including coal, gas, oil, petroleum products, and electricity. This dependence on imports shapes Morocco’s energy profile and policy.

2.2. Building Energy Efficiency in Morocco

A substantial body of literature has been published in Morocco on energy efficiency in buildings and the Regulatory Thermal Code in Morocco (RTCM). These works have yielded numerous insights, conclusions, and recommendations, all of which have been extensively deliberated and discussed. Merini et al. [20] studied a new building under construction in the city of Tangier in the Z2 climate zone. They determined and analyzed the thermal energy demanded by the building using the BINAYATE software. Different layers of materials were entered into the BINAYATE software, considering the different construction elements of the building: external walls, floors, internal slabs, partitions, doors, and windows. The analysis showed that the studied building does not comply with the requirements of the RTCM. Thus, thermal insulation of 3 cm using polyurethane was adopted for the exterior walls, and double glazing was used to achieve the energy demand limit required by the RTCM. The application of these requirements reduced the energy demand for heating and cooling by 36%. The application of the RTCM resulted in improved energy performance, indoor comfort, and energy savings compared to current energy consumption. The study showed that it is not enough to apply energy efficiency measures in the building envelope. It is necessary to apply additional measures such as lighting systems and appliances, which, together with the envelope, represent a potential savings of 69%.

Mastouri et al. [21] conducted a study to evaluate and compare the thermal performance of an existing building with the performance requirements of the RTCM. They conducted a dynamic simulation study on an existing building in BenGuerir using TRNSYS software for different configurations of some passive techniques. These techniques are hemp insulation, hollow slab, and high inertia walls. They found that the passive techniques incorporated in this real house are more than sufficient to meet the RTCM requirements. On the other hand, the standard version of this house, in which these techniques are absent, does not meet the RTCM requirements. Thus, it was necessary to integrate simple local materials for thermal insulation by using hemp and reinforcing thermal inertia with rocks from Bouskoura. The study concluded that the integration of an appropriate envelope is necessary to ensure indoor thermal comfort and reduce the effects of temperature fluctuations. In addition, the walls, roof, and glazing are key factors of the building envelope because they are directly exposed to external climatic conditions, such as solar radiation, air temperature, humidity, and wind.

El Kadiri et al. [22] proposed two designs of two-story low-energy houses with an area of 35 m² each in the city of BenGuerir in Morocco (Zone 5), taking into consideration several factors such as the climatic context, the targeted energy performance, and the required thermal comfort level. Then, they compare the results of the proposed designs to a conventional house. The proposed house designs merged local and sustainable building materials with innovative solutions to result in affordable passive houses, which helped to reduce the energy demand of the buildings and increase indoor thermal comfort. They suggested the use of double clay hollow brick walls in the first house with hemp wool insulation, roof, and first-floor slab reinforced concrete floor with a layer of hemp wool. In the second house, the walls are made of a single wall of hollow clay bricks, plaster, and a layer of extruded polystyrene. The roof and the first floor are also composed of a reinforced concrete slab with extruded polystyrene insulation. After analysis, it was found that the standard house, which has no thermal insulation, does not meet the requirements in terms of the transmission coefficient of the envelope elements imposed by the RTCM. On the other hand, the first and second houses, which were insulated with a layer of insulation, meet the requirements of the RTCM.

2.3. Novelty and Research Contribution

This research presents a comprehensive and distinctive assessment of the Moroccan Thermal Construction Regulation’s (RTCM) application in public buildings. Emphasizing the tangible potential of adopting a performance-based over a prescriptive approach, this investigation fills a significant gap in the existing literature on Moroccan energy policy, given the limited scrutiny this aspect has previously received. The investigation is rooted in building performance, chiefly the degree of compliance of public buildings to the RTCM, along with the consequential impacts thereof. The rationale for concentrating on public buildings arises from various strategic considerations.

Initially, the public equipment sector in Morocco represents a significant fraction of the national budget, earmarking 10.2 billion dirhams for 2022 and actualizing 4.616 billion dirhams in 2021 for new construction and renovation. Importantly, public buildings, as inherently energy-intensive structures, represent a key leverage point for energy policy, especially given the unique economic dynamics whereby the building users are not direct contributors to the economic investment during design or operational phases.

Public buildings are also noteworthy for their symbolic representation of the state’s commitment towards sustainability, thus rendering them a crucial focal point for energy regulation research. Lastly, the trend of the Moroccan private sector to incorporate successful initiatives spearheaded by the state amplifies the potential influence of this research on RTCM compliance within public buildings.

3. Materials and Methods

3.1. Data of the Conventional Public Building

In this study, we primarily focus on the materials constituting the building envelope, as this is the subject of the RTCM. To identify the typology of the envelope in public buildings, we adopted a methodology that involves the analysis of public contracts. We selected a sample of 10 contracts from the public contracts portal and conducted a comprehensive review to identify the construction materials related to the building envelope.

To assess the energy compliance of a building in Morocco, it is essential to determine whether it meets the requirements of the RTCM using one of the two approaches: prescriptive approach (A-Pres) or performance approach (A-Perf). To verify the compliance of a building according to the A-Pres., the thermal transmittance coefficients (U) of the different elements composing the envelope must be calculated, namely: the roofs, the exterior walls, and the glazed openings, as well as the equivalent solar factor (FS*) and the thermal resistance (R) of the floors on the ground, and then compared to the limit requirements given in the RTCM according to the thermal zone and the value of the TGBV. The A-Perf is mandatory for a TGBV higher than 45%. The verification, according to the A-Perf approach, is based on dynamic thermal simulation. This requires modeling a typical case on standard simulation software. Figure 1 provides an overview of the methodology adopted in this paper.

3.2. Dynamic Thermal Simulations

The selected software for dynamic thermal simulation analysis is Design Builder, a dynamic thermal simulation tool that offers a user-friendly graphical interface with multiple functionalities. The climate data were provided to the DesignBuilder software under EPW extension day by day between 1 January and 31 December 2020. The simulation process was carried out for all climate zones, considering 3 distinct TGBV cases and various envelope elements. This resulted in a total of 126 simulations.

The Annual Energy Performance (A-Perf) approach focuses on the building’s overall energy requirements, necessitating specific maximum annual energy demand (BECth) criteria for each climate zone and building type, as detailed in

Table 1. Annual specific demand thresholds in the tertiary sector in kWh/(m²·year).

Location (Zone)	Schools	Administrations	Hospitals	Hotels
Agadir (Z1)	44	45	72	48
Tangier (Z2)	50	49	73	52
Fez (Z3)	61	49	68	66
Ifrane (Z4)	80	35	47	34
Marrakech (Z5)	65	56	92	88
Errachidia (Z6)	67	58	93	88

. The values delineated in Table 1 are extracted from the Moroccan Thermal Construction Regulation (RTCM) document. These values signify the distinctive climatic classifications adopted by the Moroccan legislator. The RTCM document can be accessed via the ‘Press-Publications’ section of the AMEE’s official online portal [9].

The climatic zones denoted in Table 1 are defined as per the Moroccan legislation. These zones are the result of a thorough climatic zoning effort conducted by the National Directorate of Meteorology and the Moroccan Agency for Energy (AMEE), with the support of international expertise [8]. The zoning is based on climatic data collected from 37 meteorological stations across Morocco over a period of 10 years (1999–2008). The country’s partitioning into these zones relied upon the heating and cooling degree days criterion. The final zoning map comprises six distinct climatic zones, facilitating the efficient and effective implementation of the new regulations. This methodical zoning strategy enables precise and location-specific thermal regulations and policy planning.

3.3. Building Description

This study focuses on a Women’s Training and Skills Development Center in Joamaa, a quaint town to the north of Tangier, nestled in the province of Fahs-Anjra in the Tangier-Tetouan-Al Hoceima region. This geographical location is marked by a distinct climatic pattern that experiences humid winters and relatively hot summers, with the temperature fluctuating between 6 °C and 35 °C.

The center, with a total surface area of 852 m², is spread over two floors. The building has been designed to use the space effectively to serve its central purpose: fostering women’s training and skill development. The conditioned area of the center is 522.45 m². Figure 2 shows the architectural plans of the building and the simulation model.

3.4. Building Materials

3.4.1. Exterior Walls

Hollow bricks are the predominant products for walls (see Figure 3). Agglomerates are also commonly used, especially in the southern regions, since there are no brick construction factories in these regions. A frequently observed composition of external wall layers includes the following elements, arranged from exterior to interior:

• An exterior coating of cement and sand mortar;
• 8-hole ceramic exterior bricks (10 cm thick);
• Air gap;
• Interior bricks with 6 holes (7 cm thick);
• An interior coating of cement and sand mortar.

3.4.2. Roofs and Intermediate Floors

• Generally, the solution of the floor with beams is more present than the solution of the solid slab for the floor–roof and the intermediate floors; the most used beams are in pre-stressed concrete, prefabricated in the factory. The roof structure consists of beams and hollow blocks, a sloping form, a leveling screed (smoothed cement), a waterproofing system, and mechanical protection (concrete scuppers of 4 cm or red cement tiles). A 4 cm polystyrene or rock wool insulation was provided on the roof floor in some cases.

3.4.3. Floor on Ground

• Generally, the ground floor is composed as follows:
• Tile of 2 cm;
• Sand bed of 4 cm;
• The concrete slab of 13 cm;
• Hedgehog 15 to 20 cm or 20 cm of all-round soil.

In addition, all glazed panes exhibit a straightforward design, with thicknesses ranging from 2.5 to 12 mm. The most prevalent thickness is 6 mm, while larger glazed panes possess thicknesses of 8, 10, and 12 mm. The window joinery is predominantly composed of aluminum.

3.5. Choice of Insulation

For opaque walls, the selected thermal insulations are listed in

Table 2. Thermal insulations that meet the criteria of the A-Pres.

Walls	Extruded Polystyrene		Polyurethane (PUR)		Agglomerated Cork
	Theoretical Thickness (cm)	Installed Thickness (cm)	Theoretical Thickness (cm)	Installed Thickness (cm)	Theoretical Thickness (cm)	Installed Thickness (cm)
Flat roof	3.68	4	2.71	4	4.12	6
Exterior walls	0.50	2	0.36	2	0.56	2
Floors on the ground	NE *	NE	NE	NE	NE	NE
Insulation price (DH/m2)	79.7 DH for 2 cm for walls and 88.79 DH for 4 cm for the roof		141.62 DH for 2 cm for walls and 169.12 DH for 4 cm for the roof		180.4 DH for 2 cm for walls and 502.37 DH for 6 cm for the roof

* Not required.

. We determined the required thicknesses for each of the three insulators across the different parts of the building envelope. In addition, the characteristics of the glass available in the Moroccan market used for compliance are reported in

Table 3. Most popular types of glazing in the Moroccan market.

Type of Glazing	Single Glazing	Double Glazing (Cat 1)	Double Glazing (Cat 2)	Double Glazing (Cat 3)
Solar factor	0.69	0.47	0.60	0.35
U (W/m2·K)	5.6	2.6	2.6	2.6
Price (DH)	200–283	400–800	1040	1040
Cases for A-Pres compliance	Initial case	TGBV = 15%.	TGBV = 25%.	TGBV = 35%.

.

4. Results

In this section, the study results are presented. Initially, an examination of conformity assessment by climate zone is provided, illuminating the interplay between varying climatic conditions, and building envelope component performance. Following this, an investigation of the impacts of A-Pres compliance on building energy consumption is presented, providing insight into the effects of adherence to RTCM guidelines on energy use. Subsequently, the focus shifts to the influence of retrofitting individual envelope elements under three distinct TGBV scenarios. Comparative analyses aim to pinpoint and explain regional variations in envelope component performance and overall building energy efficiency. Ultimately, based on our findings and extensive literature review, we propose a set of recommendations to enhance both the RTCM document and its practical implementation.

4.1. Conformity Assessment and Energy Impact of A-Pres Compliance

As per the results presented in

Table 4. Conformity of the conventional envelope according to the A-Pres.

Zone	TGBV	U of Roofs (W/m2K)	U of the Walls (W/m2K)	U of the Glazing (W/m2K)	Minimum R of the Floor (m2K/W)	FS*, North	FS*, Other
Z1	15% 16–25% 26–35% 36–45%	NC 1 NC NC NC	C 2 C C C	C C NC NC	NE 3 NE NE NE	NE NE NE NC	NE NC NC NC
Z2	15% 16–25% 26–35% 36–45%	NC NC NC NC	NC NC NC NC	C NC NC NC	NE NE NE NE	NE NE NE NC	NE NC NC NC
Z3	15% 16–25% 26–35% 36–45%	NC NC NC NC	NC NC NC NC	NC NC NC NC	C C C C	NE NE NE NC	NE NC NC NC
Z4	15% 16–25% 26–35% 36–45%	NC NC NC NC	NC NC NC NC	NC NC NC NC	NC NC NC NC	NE NE NC NC	NE NC NC NC
Z5	15% 16–25% 26–35% 36–45%	NC NC NC NC	NC NC NC NC	NC NC NC NC	NC NC NC NC	NE NE NC NC	NE NC NC NC
Z6	15% 16–25% 26–35% 36–45%	NC NC NC NC	NC NC NC NC	NC NC NC NC	NC NC NC NC	NE NE NC NC	NE NC NC NC

¹ NC: Noncompliant, ² C: Compliant, ³ NE: Not required.

, the conventional envelope composition does not fully comply with the RTCM; however, partial compliance is observed. Specifically, the roof does not meet the requirements in any of the zones, while the ground floor complies only in zone 3 and in zones 1 and 2, where no specific requirements are set. Furthermore, the exterior walls comply only with zone 1. The glazing’s U-value meets the requirements in zone 1 for a TGBV below 25% and in zone 2 for a TGBV below 15%. However, since glazing compliance depends on the FS*, it is only compliant in zone 1 for a TGBV below 15%.

According to

Table 5. Impact of A-Pres on thermal demands.

Zone	Needs before the Application of A-Pres (kWh/ m2 /year)			Needs after the Application of A-Pres (kWh/m2/year)			RTCM Limit (Case: Schools) (kWh/ m2/Year)	Energy Gain in (KWh/m2/Year)	Percentage
	BECth	BERef	BECh	BECth	BERef	BECh
1	38.0	36.2	1.8	41.3	40.3	1.0	44.0	−3.3	−8.75%
2	38.8	31.7	7.1	37.3	33.9	3.4	50.0	1.5	3.91%
3	49.5	36.5	13.0	40.8	34.9	5.9	61.0	8.7	17.62%
4	48.3	21.9	26.3	35.5	27.1	8.5	80.0	12.8	26.45%
5	58.0	53.0	5.0	57.6	55.7	1.8	65.0	0.4	0.68%
6	67.7	59.0	8.8	65.1	61.8	3.3	67.0	2.6	3.87%

, the application of A-Pres results in energy savings in zones 2, 3, 4, 5, and 6, but overconsumption for zone 1. Zone 4 is the zone that benefited the most from A-Pres. Zone 4 is the coldest in Morocco. The colder the climate, the better the results of A-Pres. In fact, A-Pres has a clear impact on the annual heating energy demand (BECh), but the impact on the annual cooling energy demand (BERef) is negative except for zone 3, where it is slightly positive.

4.2. Impact of Retrofitting Each Envelope Element on Energy Consumption for 3 TGBV Cases

The TGBV has a crucial and determining role in adhering to the RTCM, as depicted in Figure 4, where three distinct TGBVs are considered: TGBV = 15%, TGBV = 25%, and TGBV = 35%.

For Zone 1: the initial state is compliant for A-Perf. For A-Pres: conventional wall complies, conventional glazing complies for TGBV = 15% and TGBV = 25%. Roof insulation increases BERef, slightly reduces BECh, but significantly increases BECth. Overall, for TGBV = 15% and TGBV = 25%, the RTCM increases the BECth; for TGBV = 35%, the RTCM reduces the BECth, but only the requirement on the glazing gives a better result. In Zone 1, it can be concluded that the A-Pres approach can eliminate all requirements except for the glazing requirement.

For Zone 2: the initial state is compliant with the A-Perf. For A-Pres: the conventional wall is compliant, and the glazing is compliant for TGBV = 15%. Roof insulation increases BERef and reduces BECh; the result is slightly positive. Wall insulation has a slight impact; double glazing contributes positively to decreasing BECth. Overall, for the 3 cases of TGBV studied, the RTCM decreases the BECth, but only the requirement on glazing gives a significant result. In Zone 2, it can be concluded that the A-Pres approach can eliminate all requirements except for the glazing requirement.

For Zone 3: the initial condition aligns with the A-Perf approach. Regarding the A-Pres approach, the conventional ground floor composition meets the compliance requirements. Roof insulation slightly increases the BERef and reduces the BECh; the result is positive. Wall insulation has a slight impact on the BECh; double glazing contributes positively. Overall, for the 3 TGBV cases studied, the RTCM decreases the BECth, but a combination of glazing and roofing requirements gives a similar result. For Zone 3, it can be concluded that the A-Pres approach can exclude all requirements except for those pertaining to glazing and roofing.

For Zone 4: Although the initial condition is A-Perf compliant, no component of the conventional envelope is A-Pres compliant. Roof insulation slightly increases the BERef and reduces the BECh; the result is considerably positive. Wall insulation has a slight impact on the BECh. Double glazing has a very slight impact on the BECh and BERef. The floor-on-floor insulation has a slightly negative impact. Overall, for the 3 cases of TGBV studied, the RTCM decreases the BECh and increases the BERef. The resulting BECth decreases, but only the requirement on the roof gives a close result. For Zone 4, it can be concluded that the A-Pres approach can exclude all requirements except for the roof requirement.

For Zone 5: Even though the initial state is A-Perf compliant, no component of the conventional envelope is A-Pres compliant. Roof insulation slightly increases BERef and reduces BECh; the result is considerably positive. Wall insulation has a slight impact on the BECh. Double glazing has an impact on the BECth and especially for the TGBV = 35%. The insulation of the ground floor has a very negative impact and makes the building go out of its initial compliance. Overall, for the case of TGBV =15%, the RTCM decreases the BECh and increases the BERef. For the case of TGBV = 25%, there is a slight decrease of the BECth with still an increase of the BERef. For the case of TGBV = 35%, the BERef and the BECh decrease at the same time, but only the requirement on the glazing, together with the requirement on the roof or on the wall, give the same result. For zone 5, the A-Pres can exclude all the requirements, and maintain the requirement on the glazing but absolutely discard the requirement on the floor.

For Zone 6: This is the only case where the initial condition is not A-Perf compliant, so no component of the conventional envelope is A-Pres compliant. Roof insulation slightly increases BERef and reduces BECh. Wall insulation has a slight impact on the BECth. Double glazing has a positive impact on the BECth, which changes with the TGBV. The floor on floor has a very negative impact. Overall, for the cases of TGBV = 15% and 25%, the RTCM increases the BERef and decreases the BECh. The resulting BECth is positive. For the case, TGBV = 35%, both BERef and BECh decrease, but only the requirement on the glazing accompanied by the requirement on the roof or on the wall will give the same result. For zone 6, A-Pres can exclude all requirements, and maintain the glazing requirement but absolutely exclude the floor requirement. In terms of compliance in Zone 6, for cases of TGBV = 15%, the glazing-only requirement, the wall-only requirement, or the roof-only requirement is sufficient; for cases of TGBV =15%, the floor requirement is sufficient. TGBV = 25%, the glazing requirement alone, or the roof requirement alone, is sufficient; for TGBV = 35%, the glazing requirement alone is sufficient.

Table 6. Summary of compliance results for different climate zones.

Climate Zone	Initial A-Perf Compliance	A-Pres Compliance	Significant Requirement(s)
Zone 1	Yes	Partial	Glazing
Zone 2	Yes	Partial	Glazing
Zone 3	Yes	Partial	Glazing, Roofing
Zone 4	Yes	Partial	Roofing
Zone 5	Yes	Partial	Glazing
Zone 6	No	Partial	Glazing

provides a summary of the compliance results for each climate zone. The initial state’s compliance with the A-Perf approach and the partial compliance of the A-Pres approach are listed. The significant requirement(s) for each zone, which cannot be excluded from the A-Pres approach, are also mentioned.

Figure 5 illustrates the annual heating and cooling trends for a TGBV of 15%. It is evident that Zone 4 experiences notably cold winters, and insulation plays a significant role in mitigating the cold, particularly roof insulation, as cold air tends to move downward. The simulations demonstrate that the conventional building largely meets the A-Perf requirements in Zones 1, 2, 3, 4, and 5 for all three TGBV cases examined. The A-Pres requirements were found to be beneficial solely for Zone 6, and adherence to the glazing requirement alone is sufficient to ensure the building’s compliance. Consequently, by implementing the A-Pres approach, the building’s energy efficiency deviates from the A-Perf requirements, resulting in an oversized structure. This highlights the advantage of adhering to the A-Perf approach for optimizing energy efficiency in buildings.

The analysis by individual envelope elements was a crucial aspect missing from the A-Pres design methodology. Furthermore, the RTCM guide does not explicitly outline the process for deriving A-Pres requirements. The guide only states that the requirements were determined by considering additional investment costs and thermal simulations, and an iterative process was employed to establish reasonable regulatory levels for these requirements. This lack of clarity in the methodology highlights the need for a more transparent and comprehensive approach to addressing energy efficiency through building envelope design.

4.3. Comparison between Zones

Figure 6 illustrates the diverse effects of the envelope component’s compliance with the RTCM A-Pres requirements for distinct TGBV across six climatic zones:

• Errachidia, the desert Zone 6, has the highest energy intensity, followed by Marrakech (semi-arid Zone 5), Fez (continental Zone 3), Ifrane (cold Zone 4), Tangier (Mediterranean Zone 2), and Agadir (Atlantic Zone 1). This trend could be attributed to the more extreme weather conditions experienced in Zone 6, resulting in higher energy demand for indoor climate control.
• The impact of roof insulation varies across zones. In Agadir (Zone 1), it results in adverse effects, likely due to the mild Atlantic climate where increased insulation could trap undesired solar heat. The benefit of roof insulation gradually increases, moving towards colder climates and becoming highly beneficial in Ifrane (Zone 4). However, its effectiveness tapers off slightly in Zones 5 and 6, which experience more extreme temperatures.
• Wall insulation, though negligible in Zones 1, 2, and 3, offers slight improvements in the colder and more extreme Zones 4, 5, and 6. It indicates how insulation effectiveness is tied to the region’s climatic conditions.
• Roof insulation takes precedence over wall insulation in the colder zones of Fez and Ifrane (Zones 3 and 4) due to the phenomena of thermal buoyancy aiding in the retention of internal heat. This dynamic changes in the desert zone of Errachidia (Zone 6), where summer losses counteract winter gains through insulation.
• Ground floor insulation consistently escalates thermal Building Energy Consumption (BECth) across all zones, implying a misalignment of RTCM A-Pres requirements with climatic realities, necessitating further exploration.
• Glazing compliance significantly enhances BECth, intensifying as the TGBV expands. This indicates the crucial role of adequately designed and installed glazing in regulating indoor temperature and light in all climates.
• These observations underscore the need for climate-specific guidelines in building design and retrofit strategies to optimize energy efficiency, demonstrating the local climate’s substantial role in shaping a building’s energy footprint.

4.4. Comparison with a Colder Climate

To further analyze the impact of A-Pres in cold climates, additional simulations were conducted for the city of Berlin with a TGBV of 15%. Figure 7 shows that the RTCM’s suggestions are more substantial in cold climates such as Berlin than in the Moroccan regions. Interestingly, even in cold climates such as Berlin, the floor temperature remains moderate, as depicted in Figure 8. The thermal inertia provided by the ground floor reduces energy consumption in the building. This observation suggests that ground floor insulation may not always be an effective energy-saving measure, and other strategies may be more suitable for improving building energy efficiency in cold climates.

The RTCM, which primarily focuses on insulation, is an approach that prioritizes reducing the annual heating energy demand (BECh) over the annual cooling energy demand (BERef). This trend is more evident in colder climates. However, in Morocco, with its warmer climate, the emphasis on BERef is more significant compared to BECh. As a result, it is crucial to consider the specific climate and energy requirements when designing energy-efficient buildings in different regions, ensuring that the appropriate strategies are employed to optimize energy performance for both heating and cooling demands.

5. Discussion

5.1. Comparison of Our Results with the Literature

For the floor, various studies have highlighted the importance of not insulating the ground floor. Lafqir et al. [23] emphasize that ground floor insulation should be avoided, while Hashemi [24] concludes that it deteriorates comfort conditions. Lebied et al. [25] demonstrate that in climate zone Z2, ground floor insulation is not recommended as it results in overheating. Sobhy et al. [26] report that the thermal inertia of the floor has a beneficial effect on their case study in Marrakech and that insulating the ground floor, as required by the RTCM, increases the annual thermal load by at least 7%. Our study supports these findings by confirming the negative impact of floor insulation on building thermal performance.

Regarding the roof, Hashemi [24] states that roof insulation is the most effective strategy to improve thermal comfort and reduce overheating risk. Lamrani et al. [27] conclude that roof insulation significantly reduces energy demand in Zone 2, while Lebied et al. [25] argue that an uninsulated floor could reduce cooling demand by absorbing excess heat during summer months. Sick et al. [8] and Sobhy et al. [26] also support roof insulation as an effective energy-saving measure. Our study shows that roof insulation is particularly beneficial in zones 3 and 4, and retrofitting only the roof provides better results than retrofitting the entire envelope in certain scenarios.

For walls, Hashemi [24] concludes that exterior wall insulation is effective, but not as effective as roof insulation. Our study reveals that the impact of wall insulation, as required by the RTCM for all zones, is negligible. However, there are more favorable results when retrofitting the entire envelope for zone 5 and similar results for zone 6, excluding the TGBV = 35%.

Concerning glazing, Sick et al. [8] show that energy demand could be reduced by about 50% by introducing 30% Fs glazing. Lafqir et al. [23] recommend double-glazing in most climates and triple glazing in cold climates. Saidur [28] and Lebied et al. [25] also support the use of advanced glazing and shading devices to reduce energy consumption. Our study indicates that the impact of glazing retrofit depends on the thermal zone and the TGBV. The reduction of the BECth following glazing retrofit is more significant for high TGBV, except for zone 4, where glazing is not the key element for BECth reduction.

5.2. Comparison of Our Results with the RTCM Predictions

Table 7. Comparison between the RTCM indications and the results of this case study.

Indicator	Our A-Pres Case Study *	Reference RTCM (School Establishment) *
The energy gain kWh/m2·year	Between −3.3 and 14.72 kWh/m2·year	23 and 202 kWh/m2·year
Additional investment cost for compliance (*)	Between 1.28% (51.05 DH/m2) in zone 1 and 8.83% (353 DH/m2) in zone 4	Between 1.93% (77 DH /m2) in zone 1 and 5.23% (209 DH /m2) in zone 4

(*) We referred to the “Technical Guide on Thermal Insulation of Buildings in Morocco” to calculate the additional costs associated with compliance. The reference values are taken from the RTCM guide.

shows a comparison between the RTCM’s indications and the results of this case study. The additional investment costs associated with compliance in our study are close to the RTCM forecasts. However, there is a significant difference in energy gains.

In addition, the additional cost was calculated by considering the difference between the building’s initial construction cost and that of the renovated building, brought into line with RTCM regulations. This includes expenses such as insulation, the additional cost of replacing single glazing with double glazing, and the cost of implementing modifications. The elements taken into account in our study are vertical walls, horizontal walls, surface area, and type of glazing. The insulation costs taken into account for each element are shown in Table 2 and Table 3. We then established the costs for each scenario (specific to the type of insulation) required to meet A-Pres requirements.

The range of costs observed extends from a minimum of 51.05 DH/m² to a maximum of 353 DH/m²; as depicted in Table 7, the A-Pres protocol may lack efficiency in terms of cost optimization. Indeed, the International Energy Agency (IEA) recognizes the substantial expense of implementing RTCM as the foremost factor impeding its widespread application.

5.3. Comparison between the Two RTCM Approaches

A significant gap exists in the literature regarding comparing the two RTCM methodologies. This work presents a comparison in terms of compliance with conventional primary buildings (PBs). Following the simulations presented in this study, the Moroccan conventional building is 83% compliant according to the A-Perf approach but 0% compliant according to the A-Pres approach. Consequently, by choosing the A-Pres, one may be working to bring into compliance buildings that are already compliant, which results in a loss of investment and an unwarranted delay in construction.

Moreover, simulations reveal that there are buildings that meet the A-Pres requirements but are less efficient than conventional buildings (especially in Zone 1). This leads to not only a loss of investment and delay in construction but also to a higher operating cost or a decrease in comfort in case of no air conditioning. In fact, the A-Pres approach does not accurately reflect the energy reality of the building, and therefore does not enable making well-informed decisions. With the A-Perf approach, it is possible to have a low-cost building, even without additional investment. While the A-Pres approach is easier to control and allows for obtaining a certificate of compliance quickly, this does not justify the drawbacks it creates.

5.4. Energy Efficiency Improvements in the RTCM

The literature review reveals that significant energy savings and emission reductions can be achieved through various strategies such as advanced glazing, compact fluorescent lamps, efficient heating and cooling systems, insulation, housekeeping, and appropriate thermostat settings [28]. The incorporation of passive cooling into RTCM designs has also been shown to improve thermal performance in specific locations [22]. Abdou et al. [3] suggest that the building orientation, glazing type, and infiltration rate should also be taken into account in the RTCM in order to achieve significant energy savings of over 21%.

Several studies propose various construction modifications, bioclimatic architecture principles, and the use of bio-based materials to enhance energy efficiency [29,30,31,32]. Some authors emphasize the need to expand the current RTCM to existing buildings and improve zoning methodology [33,34,35]. Sobhy et al. [26] suggest that the evaluated house demonstrates superior performance compared to a configuration adhering to the RTCM requirements across both investigated climate zones. As a result of our analysis and the current literature, we have identified several potential strategies for improving the RTCM.

For the development of the RTCM document, we suggest to:

• Provide advanced glazing, compact fluorescent lamps (CFL), efficient air conditioning systems, efficient lighting installations, a minimum solar contribution for domestic hot water, and a minimum photovoltaic contribution for electrical energy;
• Study the orientation and compactness of the building in advance;
• Consider the architectural design, the suitability of building materials with a climate system adapted to the local climate, passive cooling;
• Limit the TGBV per area;
• Revise insulation requirements, adding it where it is beneficial (roof for Zone 4) and removing it from areas where its negative impact has been demonstrated (ground floor for all zones, roof for Zone 1);
• Add requirements for the thickness of the air space, considered as a free insulator, and integrate requirements on the thermal inertia of materials;
• Provide ventilation and infiltration control (require maximum infiltration rate in cold areas, and add natural ventilation requirements in warm areas);
• Provide exterior wall and roof color requirements;
• Integrate energy management techniques;
• Review the comfort zones according to the thermal zones;
• Extend the RTCM to existing buildings.

For the development of RTCM implementation, we suggest to:

12.

Provide a study on incremental costs by differentiating between the two approaches;

13.

Improve the thermal simulation software, and make available conventional elements and materials;

14.

Produce a detailed guide covering the normative and regulatory devices to be taken into account in the study and design phases of buildings responding to the RTCM;

15.

Develop mechanisms for monitoring and verifying the application of the RTCM in contracts and on sites (auditor training, verification equipment, procedures);

16.

Develop state subsidy mechanisms;

17.

Develop communication around the RTCM, as well as training and awareness on EE.

In addition, to gain a comprehensive and integrated perspective on the future of the RTCM, it is essential to engage practitioners, such as architects, engineers, real estate developers, design offices, project managers, and other stakeholders in the building industry. Conducting a survey among these professionals will provide valuable feedback on the technical applicability of the RTCM and help identify the challenges that hinder its implementation.

6. Conclusions

Our study of the energy efficiency of public buildings in Morocco according to the Morocco’s Thermal Regulation of Buildings (RTCM) showed a significant gap in compliance with the RTCM’s prescriptive approach, despite 83% compliance with the performance approach. The advantages of the performance approach over the prescriptive approach were highlighted, as the latter often leads to over-dimensioning of building elements and insufficient optimization.

In addition, the important role of the TGBV ratio in compliance with the RTCM was discussed. The analysis showed that the performance-based approach (A-Perf) generally resulted in initial compliance for the different climate zones. However, the prescriptive approach (A-Pres) allowed partial compliance by identifying certain critical elements requiring special attention in each zone. The analysis highlights the variable influence of the RTCM A-Pres approach on energy efficiency in different climate zones, highlighting the impact of compliance of different elements of the envelope. Roof insulation gives mixed results depending on the zone, while wall insulation improves energy performance only slightly in zones 4, 5 and 6. Glazing compliance systematically reduces BECth in all zones, particularly as the TGBV increases.

Finally, this study suggests further research and exploration of energy saving techniques that could be incorporated into the RTCM and its implementation. Through the revision of the RTCM and its adaptation to the Moroccan context, the thermal regulation of buildings in Morocco can be significantly improved, leading to greater energy efficiency and long-term cost savings.

However, this study, like the RTCM, focused mainly on the building envelope, neglecting the impact of internal systems and occupant behaviour. The focus of future research will be on zone-specific RTCM compliance strategies. A more in-depth study of the role of thermal buoyancy in cold zones could help refine roof and wall insulation strategies. Roof and wall insulation strategies could be refined by a more detailed study of the role of thermal buoyancy in cold zones. The continuing negative impact of ground floor insulation requires re-evaluation and exploration of alternatives.