## 1 Introduction  
One-third of the world's greenhouse gas (GHG) emissions come from the construction industry, which is one of the biggest contributors to global warming [1]. Global efforts have been made to design new net-zero energy buildings (nZEBs) [2] and to increase the energy efficiency of existing buildings [3] in order to counteract the climate changes brought on by GHG emissions that can affect outdoor air thermal conditions [4] and increase air pollutant levels in urban areas [5]. These factors have increased the focus of researchers on the topics of reducing energy consumption in buildings [6], analysing outdoor air temperature variations in an urban context [7] and assessing mitigation techniques of the urban heat island phenomenon [8]. Since they make up the majority of the building stock and are lacking in fundamental energy efficiency components, retrofitting existing buildings offers significant energy efficiency potential in comparison to new buildings built as nZEBs [9]. Numerous studies on the best guidelines and methods for conducting energy efficiency retrofits for individual [10] and stocks [11] of existing buildings can be found in the literature. These studies are frequently motivated by initiatives taken by the majority of countries to achieve carbon neutrality for their economies. However, historical structures are excluded from energy-saving initiatives in order to preserve their significance to architectural history. Retrofitting historic buildings used to be considered a possible danger to their worth, but that is changing now. Furthermore, several studies have found that rehabilitated historic buildings in Europe--the majority of them in Italy, followed by the United Kingdom, Spain [12], and China [13]--have significantly improved their energy efficiency. Finding a balance between energy efficiency and thermal comfort while also protecting cultural property is essential for upgrading historic structures. For instance, adding outside wall insulation is not an option since it alters the aesthetic character, but updating inside energy systems, such as lighting fixtures and appliances, is completely compatible. Additionally, installing building-integrated solar photovoltaic systems is feasible in the majority of situations and merits serious consideration [14]. Previous studies offered system methods [15] and assessed a number of retrofitting options, including energy efficiency measures relating to envelopes [16], heating, ventilating, and air conditioning (HVAC) systems [17], a combination of both envelope and HVAC systems [18], and occupant behaviour [19]. For instance, [PERSON] et al. [20] used experimental and numerical assessments of an Italian administrative building to establish a multi-criteria strategy for energy retrofits of ancient structures. A number of energy-efficiency methods were assessed in the study, including wall thermal insulation, air leakage, setpoint management, window glazing, and heating systems. The study's findings indicated that energy retrofits might cut the building's principal energy usage by 20%. In a protected residential complex in London, [PERSON] and [PERSON] [19] investigated the advantages of energy retrofits using both physical and behavioural treatments. The research presented three potential retrofitting levels, including capital, cost, and payback period-based energy efficiency enhancements of HVAC and envelope systems. According to the investigation, behavioural modifications create significant prospects for energy savings (62-86%) that sometimes even outweigh physical advancements in energy efficiency.