2025 Volume 13 Issue 2 Pages 72-89
The United Arab Emirates (UAE) addresses the rapid construction growth by prioritizing optimal retrofit solutions for existing buildings. The primary objective of building envelope retrofitting is to reduce energy consumption and enhance passive design strategies. This research thoroughly examines building envelope retrofitting measures emphasizing the importance of energy efficiency. The study also compares two other residential building codes of places similar to Abu Dhabi's climate, provides an overview of the current building stock in UAE and the architectural identity of the capital city of Abu Dhabi. Inferences from the literature review was used to develop a retrofit review matrix suited for evaluating the retrofit strategies of Abu Dhabi. Furthermore, the paper utilizes energy simulation case studies of two existing buildings in Abu Dhabi, comparing the influence of Wall-window-ratio, window shades, glass properties, HVAC system and PV panel efficiency and surface coverage. It explores methods for retrofitting residential building envelopes to advance greener energy optimization standards in Abu Dhabi aiming to guide future projects and improve the capital's building portfolio database. Given that many buildings, including historical ones, are expected to remain until 2050, retrofitting represents a vital opportunity to enhance urban environments. This approach not only improves occupant comfort but also maintains essential functional aspects such as thermal, visual, and acoustic performance, ultimately leading to reduced energy consumption.
According to a 2018 report by Arup Engineering Group, buildings account for approximately 40-50% of the construction industry’s impact on urbanization (ARUP, 2018). Achieving zero-carbon communities and addressing climate change by 2050 is attainable, considering that the global building stock entails renovation and upgrades to meet new energy codes, reduce fuel consumption, and lower greenhouse gas emissions. Retrofit application is one of the most environmentally friendly and efficient strategies for optimizing energy performance. Retrofitting not only extends the lifespan of existing and historic buildings but also ensures optimal thermal comfort for occupants, ultimately leading to increased productivity (Khairi, Jaapar et al., 2017). The US Environmental Protection Agency highlights the environmental advantages of reusing existing structures, noting that it can take approximately 50 years for a new energy-efficient building to offset the energy savings lost when an old structure is demolished (Gail and Anne, n.d.) .
A building's envelope acts as the primary barrier between the external environment and the interior conditioned space, playing a crucial role in maintaining the comfort of occupants. This envelope is composed of several key components, including roofs, walls, fenestration (which encompasses glazing and frames), and foundations (Chris, 2016). Each of these elements works together to protect the interior from external weather conditions, such as heat, cold, wind, and moisture, while also ensuring the structural integrity of the building. The building envelope not only shields the interior space from the natural elements but also contributes to regulating indoor environmental conditions, such as temperature, humidity, and air quality, which are essential for the comfort and well-being of the occupants.
Given its role as the interface between the unconditioned external environment and the conditioned interior space, the building envelope significantly influences a building's overall energy consumption. A well-designed and properly insulated envelope minimizes unwanted heat transfer, reducing the need for mechanical heating and cooling systems, which in turn lowers energy consumption and utility costs (Iwaro and Mwasha, 2013). In hot climates, like that of the UAE, the envelope's ability to resist heat gain is particularly critical, as it directly impacts the amount of energy required to maintain comfortable indoor temperatures. By optimizing the thermal performance of the building envelope, energy efficiency is maximized, resulting in both cost savings and reduced environmental impact through lower greenhouse gas emissions (Dabous, Ibrahim et al., 2022; Mouada, Zemmouri et al., 2019).
A recent survey and feedback from site engineers revealed that buildings constructed before 2001 often overlooked thermal resistance properties. Despite the potential of green strategies to reduce energy consumption by 30–80%, the existing building sector has been slow to adopt energy-efficient retrofitting. In 2007, the Urban Planning Council of Abu Dhabi took on the responsibility of creating and enforcing building regulations, including energy-saving requirements. However, mandatory energy standards introduced by the Abu Dhabi building code was not implemented until October 2014 (ADM, 2022). As a result, many buildings in the UAE were constructed with minimal or no consideration for energy efficiency, particularly those developed by builders prioritizing initial cost savings over long-term energy operating cost reductions.
With the UAE experiencing a construction boom over the past two decades, there is now a crucial opportunity during retrofitting phases to enhance energy efficiency and reduce carbon footprints (Ahmed and Asif, 2021). Upgrading facades with energy-efficient features that also enhance user comfort can bring substantial improvements while minimizing disruptions to occupants. A comprehensive retrofit approach could lead to significant CO2 reductions.
This paper investigates the retrofitting scenario of residential building envelopes in Abu Dhabi to align with greener energy optimization standards. It highlights retrofitting as a key strategy for enhancing urban environments, especially given that two-thirds of existing buildings are expected to remain in use by 2050 (Meziani and AlRifai, 2023). The study focuses on understanding how to retrofit building envelopes for energy efficiency, examining critical measures and factors involved in the process. It compares residential building codes of Abu Dhabi-UAE, Phoenix- Arizona, and Darwin-Australia, with an emphasis on envelope components, materials, air infiltration prevention, and minimum U-factor requirements. The paper also considers the preservation of Abu Dhabi’s architectural identity and explores engineering solutions for retrofitting buildings constructed before 2014. Additionally, it analyzes two energy simulation models of residential buildings from 1977 and 1992, and compares the energy performance based on the retrofit review matrix developed. Proposals for retrofitting residential building envelopes are suggested that can be executed on buildings constructed after the implementation of Abu Dhabi’s building codes in late 2014.
Literature review explored the relationship between climatic conditions and building codes in their approach to retrofitting, by comparing three building codes from climate zones similar to Abu Dhabi’s. Different retrofit approaches and strategies in residential buildings were identified and a retrofit review matrix was developed including the most significant parameters within each of the five key aspects of retrofitting. This review matrix is then utilised in proposing suitable retrofit measures for buildings in Abu Dhabi.
Relation between bilding codes and cimatesEnergy-efficient building envelopes transcend being mere barriers between interiors and exteriors; they function as building systems that actively respond to the external environment, significantly reducing energy consumption. These envelopes incorporate high thermal resistance materials in the facade, employ vapor barriers for effective vapor control, utilize efficient window and door seals, and implement airflow control measures to minimize the infiltration of outdoor air, creating comfortable and energy-efficient spaces (Charisi, 2017).
Envelope materials and insulation techniques used in building envelopes vary widely across different countries due to differing regulations, which shape the construction practices. Additionally, the climate of each region influences the design objectives of building envelopes and the level of protection they need to provide (Kim and Kwak, 2022). In this section, the building codes of two cities; Phoenix- Arizona, and Darwin-Australia with similar climatic conditions to that of Abu Dhabi, were explored and compared. Cities with comparable climates for the study were selected by referring to the Köppen-Geiger climate classification map, which was originally developed by Wladimir Köppen and later modified by Rudolf Geiger. Building envelope retrofitting approaches mandated in these building codes were analysed and compared. Figure 1. Comparison of Retrofit Applications and Materials in different Building Codes shows the comparison of retrofit application and measures for roof and walls, across different building codes.
Building retrofit focuses on improving the energy efficiency of an existing structure by making various modifications. This process encompasses alterations made to the building's systems, equipment, and operations, aiming to enhance the overall energy performance of the building, leading to reduced energy consumption, lower operational costs, and improved environmental impact (Fernandes, Santos et al., 2021).Table 1 compares two retrofit types, deep retrofit and shallow retrofit. Deep retrofitting involves extensive modifications to a building's envelope to significantly enhance its energy performance and sustainability. Shallow retrofitting, on the other hand, focuses on less intrusive improvements that can be implemented with minimal disruption and lower costs (Semprini, Gulli et al., 2017).
| Deep retrofit | Shallow retrofit |
|---|---|
| A retrofit including work to most of the building fabric and changes to the building’s heat source and ventilation systems. This type of retrofit would typically occur at the same time as significant renovations or extensions. | A retrofit involving several minor interventions (façade or roof insulation, cavity wall insulation), including changing the heat source and ventilation systems. |
| Percentage of energy demand reductions and associated co-benefits from deep retrofits is 70%, with consideration for all significant capital need in the project over the next several years and plan interventions to this business-as-usual scenario to create higher efficiencies and other benefits. | The percentage of energy demand reductions and associated co-benefits from shallow retrofits is 30%, with a more extended payback period. |
Energy-efficient retrofit involves utilizing advanced technologies and systems to safeguard and maintain urban areas and their constituents, aiming to decrease carbon emissions and reduce energy consumption linked to the built environment (Biloria and Abdollahzadeh, 2022). The success of energy-efficient retrofitting relies on effectively insulating and redesigning the building envelope to meet present requirements. Energy efficiency is applied to various building components, including roofs, floors, walls, fenestration, and foundations. Table 2. Retrofit applications on the envelope components. consolidates the various residential envelope retrofit strategies identified from literature studies. The studies point to the fact that a bundle of energy conservation measures produce more effective results and that traditional strategies can be as effective as more innovative solutions in terms of energy saving (Ahmed and Asif, 2021; Kamel and Memari, 2022) .
| Envelope components | Retrofit method | ||
|---|---|---|---|
| Insulation application | Energy-efficient application | Renewable energy sources | |
| Roof | Low heat transmission coefficient (λ) is the main feature of thermal insulation materials. Commonly used thermal insulation materials for wall, floor, and roof insulation are glass wool, mineral wool, and polyurethane. | Green roofs are passive cooling techniques in warm air conditions that stop incoming solar radiation from reaching the building structure below and provide an additional thermal insulation layer with soil in cold air conditions. | Photovoltaic panels. |
| Thin-film photovoltaic roofing materials. | |||
| Solar collectors. | |||
| Photovoltaic panels can be placed directly on the roof surface or roofing material to protect from weather conditions. | |||
| Walls | Improvising thermal resistance is provided by reducing the coefficient of thermal conductivity. 30-60% of heat loss occurs in uninsulated buildings. | Integration of shading elements; unwanted heat gain is prevented. | Photovoltaic panel application. |
| Transparent Insulation (TI) is the most popular application that aims for passive heating. | The load on the mechanical cooling system is reduced through shading elements. | Double skin façade if affordable. | |
| Fenestrations | PVC (polyvinyl chloride) frames have good insulation values; they increase through the small cavities within the vinyl frame. |
Replacement/ Renovation of old frames with energy-efficient types is essential in increasing the efficiency of existing buildings. (U aluminium = 10, 80 W/m²K); (U timber = 2.27 W/m²K) is lower than aluminium frames. |
Integrated concentrating dynamic solar systems applications. |
| Glass: Coating the surface of the glass material with a reflective film to reduce glare and solar heat gains. Filling gas between the layers of glass as an insulation material: Argon/Krypton and improved insulation of frame constriction. In double-layer applications, glazing performance increases 11% by Argon gas infill and 22% by Krypton gas infill. | |||
| Foundations | Footings: Improved insulation of foundation. | There are relatively few proprietary issues associated with foundation rehabilitation and retrofitting. | |
| Floors: Improving Thermal Resistance by thermal insulation materials such as polyurethane. | |||
When it comes to retrofitting existing buildings in various countries, the focus is often on structural or aesthetic measures, particularly for historical buildings aimed at conservation. However, equal importance is placed on reducing energy consumption levels due to its significant financial impact. Enhancing indoor air conditions and lowering fuel consumption in existing buildings not only contributes to better living conditions but also results in reduced carbon dioxide emissions, contributing to a less polluted environment (El-Darwish and Gomaa, 2017).
Governments globally, including the UAE, have implemented robust initiatives to retrofit existing buildings and enhance energy efficiency. The European Energy Performance of Buildings Directive, for instance, requires achieving a 20% energy savings target by 2020 (EPBD, 2019). In the USA, the Department of Energy (DOE), which participates in both the ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) and ICC (Internal Codes Council) development processes, developed and submitted code change proposals that strive to make cost-effective, energy-efficient upgrades to current model codes (U.S. Department of Energy, n.d.). In the UAE, Estidama represents a building design approach geared towards creating more sustainable buildings and communities during both construction and operation. It strives to establish a framework for assessing sustainability performance that goes beyond the conventional planning and construction phases. The updated technical envelope standards now incorporate mandatory criteria for envelope verification, supporting the reduction of air infiltration, and heightened requirements for air leakage in overhead coiling doors. There are also more rigorous standards for metal building roofs and walls, fenestration, and opaque doors. Enhancements include clearer definitions of exterior walls, improved building orientation, and increased transparency regarding the effective R-value of air spaces. Building energy codes are in place to ensure efficient energy use throughout the building's lifespan.
Locating residential structures dating back to the 1960s in Abu Dhabi poses a challenge, with a considerable number of them having already been demolished. The scarcity of fresh water in the region led to the use of saltwater from the Arabian Gulf in concrete mixing, exposing the buildings to the corrosive effects of salt. For instance, certain structures from the late 1970s in the city managed to endure only until the 1990s, necessitating their demolition.
Scenario of residential building stock in the UAEThe 2012 survey aimed to assess potential energy savings within the existing building stock of the UAE. However, data collection was challenging due to the federation structure of the UAE, where each of the seven emirates is responsible for its own building regulations. The study focused on the emirates with the highest population and number of buildings: Abu Dhabi, Dubai, Sharjah, Ajman, and Ras Al Khaimah, along with federal buildings. Fujairah and Umm Al-Quwain, which represent less than 10% of the UAE’s population, were not included. Additionally, the Ministry of Public Works (MoPW) oversees public housing construction for UAE nationals in the Northern Emirates but does not handle projects in Abu Dhabi and Dubai.
The 1985 Abu Dhabi building regulations mentioned thermal insulation but did not specify values, and insulation regulations were only present in Abu Dhabi, Dubai, and Sharjah. Three periods of thermal insulation guidelines have been identified: pre-2003 (no insulation regulations), 2003-2011, and post-2011. Since 2000, Abu Dhabi has seen a significant rise in high-rise residential buildings compared to the earlier predominance of low and medium-rise structures. Over 80% of residential units were built before the implementation of the Abu Dhabi building code (AlNaqbi, AlAwadhi et al., 2012). Figure 2 represents the growth of residential buildings in the emirate of Abu Dhabi from 1975 to 2021.
The analysis of energy efficiency should encompass more than just individual buildings, incorporating strategic district-level approaches to maximize retrofit investments. This section reviews the literature on the topic, focusing on five key aspects essential for conducting a comprehensive and reliable energy efficiency study at a portfolio level. Ruggeri’s "review matrix" provides a structured theoretical framework, based on previous experience, for understanding the existing literature. They are energy modelling and assessment, energy retrofit design, decision-making criteria assessment, optimal allocation of (financial) resources and risk valuation. These five aspects represent critical steps for a thorough and credible energy efficiency evaluation. While we apply these aspects to energy retrofitting in European building portfolios, it is worth noting that despite climatic differences between the hot UAE and Europe, European countries lead in sustainable and environmentally friendly architectural practices (Ruggeri, Gabrielli et al., 2020).
The first aspect involves energy modelling and assessment, where the energy consumption of each building needs to be estimated at both the current state and the design stages. This necessitates comprehensive information about the building's materials, technologies, geometry, climate, installations, facilities, users' occupation schedules, and behaviour. Each building must undergo modelling using specific computer software or detailed statistical simulations to evaluate its energy needs (Seghier, Lim et al., 2022).
The second element involves the design of energy retrofit solutions. A range of energy efficiency measures needs to be planned, considering the capacities and constraints specific to each building. It is generally advisable to explore various alternatives or retrofit scenarios to pinpoint the optimal solution (Fernandes, Santos et al., 2021) .
Thirdly, the evaluation of decision-making criteria is essential. It is vital to assess various criteria for decision-making to compare and rank the alternative scenarios put forth. This assessment may include considering factors such as energy savings, cost savings, environmental advantages, capital expenditures, or other relevant aspects (Pombo, Rivela et al., 2016). Multifarious and conflicting factors such as environmental, economic, social, and technical performance further complicate the decision-making process. Frameworks to evaluate energy retrofit strategies and to identify a compromise retrofit scenario which considers all stakeholders involved becomes paramount (Ongpeng, Rabe et al., 2022).
Fourthly, the optimal allocation of resources involves identifying the most effective energy efficiency measures across the portfolio, considering various objectives within specified constraints(Kheiri, 2018).
Lastly, risk valuation. The last issue involves risk assessment and quantification, including the complex and variable nature of the problem(Tian, Heo et al., 2018).
Table 3 consolidates and present the key aspects of energy efficient approach that take a front stage while considering the retrofitting scenario of existing residential buildings in Abu Dhabi that were constructed before the implementation of building codes.
| Energy modelling and assessment |
|---|
|
| Energy retrofit design |
|
| Decision-making criteria assessment |
|
| Optimal allocation of resources |
|
| Risk valuation |
|
Developed by authors, data gathered from: Di Pilla, Desogus et al., 2016; Hammond and Jones, 2008; Heidari, Majcen et al., 2018; Kheiri, 2018; Palma, Gouveia et al., 2019; Pombo, Rivela et al., 2016; Ruggeri, Gabrielli et al., 2020; Tian, Heo et al., 2018; Wang and Wang, 2012
This study on retrofit strategies for building envelopes employs a structured approach that combines building code reviews, case studies and energy simulations to evaluate the effectiveness of various retrofit techniques. The methodology is designed to provide a comprehensive understanding of how different strategies impact energy efficiency and the overall building performance in the context of Abu Dhabi's climate. The study was conducted in two phases. The first phase was an extensive literature review to understand the significance of building retrofit as an important strategy to achieve energy savings in the existing building stock. Literature studies reviewed the relation between climates and building codes in their approach to building retrofits. Three building codes from similar climate zone to that of Abu Dhabi were reviewed and compared. The study on retrofitting strategies applied to the existing building envelopes and the governmental policies as prescribed in the codes, led to the identification of deep retrofits and shallow retrofits as the two major approaches to retrofitting and further the identification of five key aspects of retrofit review matrix. A thorough study on these five key aspects of review matrix was done to identify the most significant parameters under each aspect which helped in proposing suitable retrofit measures for buildings in Abu Dhabi.
Second phase of the study focused on conducting case studies and simulating the energy performance of retrofit cases, also to arrive upon the optimum strategy. An investigation of the existing housing stock in UAE led to the selection of two case study buildings that represent two different construction eras. Building Information Modelling package of Autodesk including REVIT was utilized to create a 3D model; Insight and Green Building Studio were employed to run building performance simulations. As a leading Building Information Modelling (BIM) software, REVIT enables precise representation of the building's energy usage and performance.
In this study, two retrofitted residential buildings in Abu Dhabi were analysed, focusing on the key aspects of the review matrix identified earlier. This is to examine how each building implements distinct approaches to enhancing energy efficiency and evaluate the effectiveness of different energy efficiency strategies. The identified case study buildings were constructed in different periods. The first case study, Huwairib Al-Mansori building was built in 1992 before the enforcement of energy conservation codes in Abu Dhabi, while the Alfawar building represents the second case constructed in 1977. Energy simulations of both the case studies were conducted in REVIT, Insight and Green Building Studio, to illustrate the energy optimization of each building, highlighting the impact of wall and glazing heat conductivity on energy conservation.
Case 1: Huwairib Al-Mansori Building
Figure 4 shows the Case 1: The Huwairib Al-Mansori Building, which is a midrise structure built in 1992. The walls of the building were made up of two layers of dense concrete masonry units, with two air gaps separating insulation layers made of polystyrene. The identified retrofit strategies and the comparison of the energy performance simulations before and after retrofit, are presented in the Figure 5 provided below.
The building, which was built in 1977 prior to the establishment and enforcement of building codes, was not constructed with insulation in its walls. Instead, it was built with a double layer of heavyweight concrete with an intervening air gap. This pattern was common in many buildings constructed before 2007, reflecting a lack of awareness regarding sustainability before the implementation of the Abu Dhabi building code. As a result, many structures from this period are currently in the process of being retrofitted by various contracting companies. Furthermore, the building is in a deteriorated state, which provides additional reasons for its retrofitting. Figure 6 shows the photograph and Revit model of the case 2 building. The identified retrofit strategies and the comparison of the energy performance simulations before and after retrofit of Case 2, are presented in the Figure 7 provided below.
Figure 8 shows the comparison of the energy costs in USD/m2/year before and after applying retrofit strategies to Case 1: Huwairib Al-Mansori building.
From the analysis of Case 1: Huwairib Al-Mansori building, the following inferences can be made. Window Wall Ratio impacts daylighting, heating, and cooling through window properties; and has considerable effect on energy consumption. The current window shades had a width of 50cm and were made of concrete material, which has a considerable embodied carbon value. Installation of solar breakers on the facades aided in decreasing the building's energy consumption. Controlling the amount of daylight, heat transfer, and solar heat gain in the building can be achieved through the variation of glass properties. The retrofit proposal simulation demonstrated how the utilization of double, double Low-E or triple Low-E can result in a decrease in energy consumption in comparison to a single glazed clear window glass. The existing air-conditioning ducts were single; hence the use of highly efficient VAV systems to reduce energy consumption is recommended. This system has to be implemented on all floors instead of three floors as in the existing case. PV surface coverage refers to the proportion of a roof's surface that is occupied by PV panels. This calculation considers the space required for accessibility for maintenance, rooftop equipment, and system infrastructure. According to the DMT guide for covering roofs, there is a specific area allocated for installing PV panels. On the other hand, PV efficiency measures the amount of sun's energy that is successfully transformed into AC energy, which is also known as the panel's efficiency. The surface coverage of PV panels has a significant impact on the total energy costs.
Figure 9 shows the comparison of energy cost for the base case building and the existing building. According to ASHRAE standards, the maximum cost for residential buildings is $ 30.1, while the Alfawar building exceeds the standards by about 8$ after the retrofit.
Inferences from Case 2: Alfawar Building regarding the Window to Wall Ratio is similar to that of case 1; where the percentage of window on each façade affects energy consumption both before and after the retrofit process. Shading devices play an important role in reducing emissions and have a significant impact on the energy consumption of HAVC systems. Vertical louvers in the northeast and northwest elevations and horizontal louvers added to the southern elevations achieved a reduction in energy consumption. This strategy has proven to be the optimal choice for minimizing energy usage. Nearly all buildings in Abu Dhabi in the 1970s had single-glazed windows. The buildings had opaque walls with smaller openings, consistent with traditional regional construction. Triple low-E glass exhibited highest energy consumption and is recommended to be used in future renovations. Existing case had an old window air conditioner, whereas recommendations are made for installing a new and highly efficient HVAC system. There is not enough surface area to install PV panels in the current design, or even after retrofitting. We assume that no solar energy can be used in this building roof while maintaining the roof and walls. High-efficiency solar panels can be used, but are more expensive. In this case, it's important to allocate resources optimally. After studying the economic assessment criteria, it's clear that building a new structure considering energy efficiency measures and Estidama Pearl requirements would prove to be better choice for this site.
Despite the presence of buildings in Abu Dhabi that have been in existence and occupied since the late seventies up to the early years of the second millennium, the ongoing challenge lies in preserving and restoring them. Figure 10 illustrates the biggest challenges present to deep retrofit in Abu Dhabi. In pursuit of this goal, the Abu Dhabi government and its municipality have undertaken various initiatives to retrofit these structures. One notable example in this context is the report issued by the Emirates Green Building Council in 2020 (Emirates Green Building Council, 2020). The retrofits undertaken will facilitate the decarbonization of the current building inventory, contributing to the industry's transition towards a future with net-zero carbon emissions. In our research, we concentrate on responses from Emirates Specialized Contracting & Oilfield Services, governmental sectors, developers, and building owners, encompassing eighty participants as highlighted in the EGBC survey report (IEA Technology Collaboration-Programmes, 2022).
An open-ended question was asked to gather suggestions, both financial and non-financial, that could be implemented in the UAE to expedite retrofit projects. The responses received highlighted certain key points that were unanimously agreed upon. These included the establishment of an existing building rating or labelling system to assess building performance, the provision of green loans with lower interest rates, grants or funds specifically allocated for energy efficiency projects, and the introduction of on-bill financing mechanisms to streamline financing approaches. Additionally, the 2020 report recommended offering incentives to both the public and private sectors for investing in energy efficiency projects through hedge funds, investment funds, or mutual funds, to stimulate funding for retrofits.
To comprehend how to emphasize energy efficiency, this study aims to formulate a retrofit concept for the residential building envelopes in Abu Dhabi. The methodology employed involves identifying key metrics for formulating retrofit strategies, comparing residential building codes of three places from similar climate zones, identifying critical building envelope components and their retrofit strategies, and finally analysing two residential buildings in Abu Dhabi in the light of the identified review matrix and comparing the energy consumption scenarios based on simulation results. The study focused on five review factors: energy modelling and evaluation, energy retrofit design, assessment of decision-making criteria, optimal resource utilization, and risk assessment. The study concludes with the following inferences:
· The pursuit of green designs and energy efficiency in building structures leads to the categorization of building envelope retrofits into two types: deep and shallow retrofits.
· Determining whether a building requires a shallow or extensive retrofit, or if a new construction should be demolished, hinges on crucial energy efficiency factors at the portfolio level.
· Each component of the envelope, such as foundations, walls, fenestration, and roofing, necessitates a distinct approach.
· WWR, Window shades, Glass properties, HVAC types, solar panel efficiency and surface coverage are identified as significant factors impacting the energy consumption. Varying these parameters showed significant energy savings from the simulation results.
· The majority of structures in Abu Dhabi constructed before 2014, particularly those from the 1980s and 1990s can be retrofitted to enhance their energy efficiency. However, a substantial number of buildings predating the 1980s may be more feasibly demolished to meet contemporary safety and sustainability standards.
It is important to acknowledge the limitations of this study, especially regarding the acquisition of data and information about historic existing structures. Implementing an exceptionally effective retrofitting strategy demands thorough research efforts. Verification and validation of the results need more data and hence is proposed as the future endeavour.
Conceptualization: Dr. Mohamed Elkaftangui, Dr. Rim Meziani, Asmaa Mohamed and Hassan Mustafa; methodology: Dr. Mohamed Elkaftangui and Dr. Rim Meziani and Asmaa Mohamed; software: Hassan Mustafa; investigation: Dr. Mohamed Elkaftangui, Dr. Rim Meziani, and Hassan Mustafa; data curation: Dr. Mohamed Elkaftangui; writing—original draft preparation: Dr. Rim Meziani; writing—review and editing: Dr. Mohamed Elkaftangui, Dr. Rim Meziani, Asmaa Mohamed, Hassan Mustafa and Dr. Joshima V.M. All authors have read and agreed to the published version of the manuscript.
The authors declare that they have no conflicts of interest regarding the publication of the paper.
