In Malaysia, there are several alternatives available to minimize the environmental impact from the

construction industry, including the adoption of green building construction. Many studies, however, show

that creating new green buildings may have negative influences on the environment, such as improper waste

management and a rise in building stocks in Malaysia. Thus, green retrofitting is an effective measure since it

utilizes existing buildings in Malaysia to retrofit buildings with sustainable elements, such as additional

window openings for natural lighting. However, the application of the green retrofitting concept as a factor in

Greenhouse gas emissions are a major driver of climate change, and their escalating impact on global warming

is undeniably detrimental. This issue demands urgent attention and action [2] According to the UN

Environment Programme and the International Energy Agency, the construction industry is responsible for

36% of global energy consumption and 39% of carbon dioxide emissions [3]. Despite its significant

environmental footprint, the construction sector holds considerable potential to reduce emissions compared to

other major polluting industries [4]

Malaysia has pledged to reduce greenhouse gas emissions by 45% by 2030 and has begun implementing

initiatives such as the development of carbon-neutral cities [2]. A key strategy to mitigate the environmental

impact of construction is the adoption of green building practices. These practices are widely recognized for

In recent years, there has been a significant growth in the amount of attention devoted to green retrofitting of

residential property. This is because green retrofitting has the capability to improve energy efficiency and limit

the impact that it has on the environment. Sustainable building retrofits in residential structures are not only

acknowledged by researchers as an important method to increase the energy efficiency of existing buildings,

but they are also believed to be an effective technique to reduce the amount of funds spent on energy and to

improve the performance of the building [5].

For instance, the use of a multifunctional facade system for the retrofitting of apartment buildings in Finland

and Russia, as well as the utilization of an alternative building envelope in the process of building retrofitting

in Portugal Strategies for retrofitting external insulation in wooden-framed buildings in cool areas of the

on the climatic conditions and locations of the projects [7]. The primary goal of the passive energy-saving

approach, which is extensively used, is to minimise the energy consumption of the building envelope [8].

Increasing the airtightness of the building and decreasing its heat conductivity are both necessary steps in

arriving at this goal. This concept offers an effective method for reducing the excessive demand for energy

that has been observed. In addition, research emphasises the significance of using passive design solutions,

which, when implemented in residential structures, it has the potential to cut overall energy usage by as much

as fifty percent on average [9]. It is widely accepted that the use of suitable retrofit solutions is of the utmost

significance for enhancing energy efficiency and cost-effectiveness. This is because the retrofit techniques that

are selected have a significant impact on the level of success that can be achieved in a project aimed at

enhancing the sustainability of an existing building [10].

amount of embodied energy is wasted, making the current pattern of construction unsustainable [11].

Although energy retrofitting is important, its adoption rate is still lower than expected due to many complex

factors such as design characterization, prediction methods, and performance comparison issues [6]. Several

challenges were identified when designing green retrofitting concepts for residential buildings, especially from

the architects’ perspective. One major issue appears in the pre-design stage, where architects and engineers

often have different approaches. Architects usually have limited understanding of energy modelling, while

engineers rely heavily on these models to study building form and energy efficiency [12]. This knowledge gap

makes it difficult for architects to design residential buildings that effectively integrate green retrofitting

concepts.

Architects play an essential and multifaceted role in the success of sustainable retrofit projects for residential

intermediary role of architects in connecting technical solutions with homeowners has also been emphasized

in previous studies [14]

During the design stage, architects also face problems in collecting data, which is often outdated or incomplete

[15]. This lack of reliable information limits their ability to provide effective retrofitting solutions. Moreover,

insufficient details in the existing building documentation create further barriers for architects when starting

the design process [16]. Even though design costs form only a small part of the total project budget, the

success of retrofitting projects strongly depends on the quality of the design approach used [17].

Based on the RIBA (Royal Institute of British Architects) Plan of Work, architects play a crucial role in

planning and implementing green retrofitting by integrating sustainable design principles at every stage of the

process [18]. Their responsibilities include evaluating environmental impact, improving energy efficiency, and

selecting effective retrofitting solutions through multi-method approaches that involve collaboration with

government policies and sustainability goals ([17], [21]. Overall, architects’ involvement throughout the RIBA

stages ensures that green retrofit projects are sustainable, efficient, and consistent with national carbon

Challenges Faced by Architects in Designing Green Retrofitting for Residential Housing

implementing these strategies [17].

Traditional architectural design methods, which focus mainly on form, function, and space, often fail to

include energy simulations needed for efficient buildings. Many architects are unfamiliar with these scientific

modelling tools [15]. This creates a gap between architects and engineers, especially in the early design stage,

since architects may not fully understand energy models while engineers depend on them for assessing

building form and energy use [12]. Architects therefore face difficulties in using energy optimisation tools

effectively [17].

Various optimisation software such as Matlab, modeFrontier, and GenOpt can help integrate energy

simulations in design [20] However, these platforms are not tailored for architectural use, making them

difficult for architects to navigate. Tools like Google SketchUp also lack integration with energy simulation

applications [14]. As a result, architects must switch between modelling and optimisation environments, which

Architects are central to promoting low-carbon housing because they lead the early design stages of projects

[14]. Yet, they must deal with diverse housing types, ownership patterns, and client needs [15],[25]. Balancing

these differences is difficult in sustainable retrofit projects. Architects must also be well-informed about the

benefits of green features to help clients choose measures that fit their goals [26].

Retrofitting involves many stakeholders and complex issues like building age and deterioration [27]. Even

though design costs are small, they strongly affect project success [16]. Architects often face missing or

outdated information from stakeholders [28], making it hard to create accurate retrofit designs. Many old

building records lack full structural details or are inconsistent [15]. This uncertainty makes retrofitting more

Data analysis was conducted using SPSS version 26. The Average Index (A.I.) method was applied to quantify

Malaysia, selected for their relevance to the investigation of challenges in designing green retrofitting

concepts for residential buildings. The demographic data shows that most respondents possess strong

academic qualifications, with 53.4% holding a master’s degree and 34.6% a bachelor’s degree. A smaller

Table Iii Average Index (A.I) Analysis on Challenges in The Design of Green Retrofitting for Residential

Buildings

receiving the highest A.I. score of 4.21. This reflects a strong consensus among respondents that budget

limitations hinder the full integration of sustainable features in retrofit projects. Supporting literature

reinforces this concern, noting that the absence of a suitable financial framework, coupled with low return

on investment, poses substantial risks to project viability [31]. High initial costs, uncertain payback periods,

and limited access to financial resources further complicate the execution of green retrofitting initiatives

[22].

The second-highest ranked challenge, with A.I. score of 4.13, is the lack of supportive government policies.

Respondents expressed strong agreement that policy gaps obstruct the adoption of green retrofitting

practices. This aligns with findings by [32], who emphasize the importance of government incentives—such

as subsidies and financial compensation—in encouraging developers and homeowners to invest in

and functional demands [26]. The absence of comprehensive training in architectural education further

limits practitioners’ ability to manage these complexities effectively.

These findings, supported by both empirical data and scholarly research, underscore the multifaceted nature

of barriers to green retrofitting in Malaysia’s residential sector. Financial, regulatory, and technical

challenges each play a critical role in shaping the feasibility and success of retrofit projects. Addressing

these issues requires coordinated efforts across policy development, industry practice, and professional

education to enable broader and more effective implementation of sustainable design strategies.

This study has thoroughly explored the concept of green retrofitting for residential buildings in Malaysia, with

a focus on the challenges encountered by architects during the design process. The study successfully met its

objectives by identifying key barriers and aligning them with insights from existing literature. Among the

challenges, financial constraints were consistently recognized by architects as the most critical. They

highlighted that limited financial resources, high retrofitting costs, and uncertain payback periods significantly

residential buildings with modern energy-efficient systems presents considerable design challenges. These

require specialized knowledge and a nuanced understanding of building conditions, historical context, and

material compatibility.

The findings underscore the need for coordinated efforts across policy development, financial support

mechanisms, and professional capacity-building to enable the practical application of green retrofitting in

Malaysia. Strengthening institutional frameworks and improving access to resources will empower architects

to overcome existing barriers and contribute to the development of environmentally responsible residential

environments.

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