# Urban Overheating Impact: A Case Study on Building Energy Performance
## 1 Introduction  
Buildings are the main sector responsible for energy consumption in the current world energy scenario [1]. In this context, energy retrofit interventions and the design of new, efficient buildings prove to be winning strategies. In particular, building energy simulation software become essential tools for quantifying the energy consumption of green buildings, i.e., of that type of building designed, built and managed in a sustainable and efficient manner, and for assessing the energy savings of existing buildings during the energy requalification phase. The energy performance of buildings can be assessed using stationary and dynamic simulation codes. These software require specific meteorological data to take into consideration the local environmental climatic conditions, returning the energy demands of the building. Climate data sets are known as the Typical Meteorological Year (TMY), which is a set of meteorological data characterized by values for each hour in a year, for a given geographic site. The hourly data are chosen over a longer period of time, usually 10 years or more [2]. For each month of the year, data are selected from the year that can be considered most representative for that month. Since 1994, in Italy, buildings have been designed applying the UNI 10349 standard [3]. This is a national standard that suggests monthly average values for climate data for specific sites. Its first version used data from the period 1951-1970. The Standard was updated in 2016 on the basis of the monthly average data calculated from the reference years of the tests developed by CTI [4] for various different Italian cities. Starting from this, it should be noted that nowadays, climatechange, and the consequent impact on buildings' energy performance, represents a critical issue. In fact, urban growth has led to an increase in the air temperature in cities compared to rural areas and to an expansion of the Urban Heat Island (UHI) phenomenon [5; 6]. This is caused by the increase in solar radiation absorbed by the building materials [7; 8]. The UHI phenomenon increases the cooling in urban areas [9; 10], which implies higher energy consumption that leads to an increase in pollutant levels in the urban context [11; 12]. [PERSON] et al. [13] studied the correlation between the UHI and the land use/land cover ratio from 1987 to 2016 in Wuhan, China, finding that high temperatures were concentrated in construction land. The overheating involved in the UHI phenomenon is directly related to human health. As a matter of fact, the increase in air temperature affects the outdoor thermal comfort of inhabitants [14]. This effect is more relevant in summer and, for this reason, making cities cooler plays a crucial role [15]. Therefore, in recent years there has been a significant increase in building retrofit interventions in densely built cities. In fact, in addition to the increasingly widespread use, especially in green buildings, of small renewable generators capable of reducing energy consumption [16] and the attention paid to optimizing the energy tariffs of smart buildings [17], in recent years there have been numerous interventions aimed at reducing energy consumption for cooling and improving the thermal inertia of the building, and studies on the implication of thermostatic appliances (such as air conditioners, water heaters and freezers) on saving electricity in homes, and on safeguarding the internal comfort of the occupants and the internal comfort of the occupants, have intensified [18; 19]. Recently, many studies have been focused on mitigation techniques of the UHI, such as green roofs [20; 21], cool materials [22; 23], vegetation [24; 25] and water sources [26; 27]. The adoption of mitigation strategies has an important role both for the whole cities and for localized urban areas such as urban canyons [28]. [PERSON] and [PERSON] [29] studied how the radiation balance of urban materials influences air temperature in an urban canyon.