## 2 Materials and Methods
### Analysis at the Building Level  
The recent UNI EN 16883 standard [16] states that maintaining the desired level of indoor environmental quality and user comfort should be the primary objective of most buildings. A poor indoor environment may be the reason why people attempt to improve the energy performance of a building. Thus, following extensive hygothermal simulations at the building component level, the energy simulations were extended to the building level in order to investigate the effects of the retrofitting process on the indoor environment. In this section, the same design alternatives described in Section 2.2 are analyzed. However, the configuration with a vapor barrier has not been taken into account because it demonstrated a low level of performance in the former analyses. The aims of the analysis at the building scale were:  
* To investigate the summer thermal performance of the retrofitted case study, considering the indoor comfort conditions, but without the presence of cooling systems (free-running);
* To analyze the heating and cooling energy demand for the different solutions during the winter and summer seasons. WUFI Plus software was used for both the energy demand and the internal thermal comfort assessments. WUFI Plus software is a tool for dynamic building simulations based on user-specified climate and on user-defined ventilation, HVAC and internal loads, and it allows a detailed and comprehensive assessment of the hygothermal behavior and of the thermal interaction between the envelope and enclosed space to be made. The hygrothermal behavior of the building envelope affects the overall performance of a building to a great extent, since moisture-related effects can lead to a higher energy use, as demonstrated in [28]. The analyzed building was, as previously mentioned, the Monastery of Santa Maria de Monfero in Galicia, Spain, with reference to a project for its conversion into a spa hotel. The examined indoor environment was thus a standard hotel room, as designed in the original project (Figure 4). The room model has two walls exposed to the external environment, one facing north and one east, while the other walls (partitions) and the floor were considered adiabatic. The external walls, without internal insulation, were assumed to have a thermal transmittance of 1.35 W/m\({}^{2}\)K, while a U-value of 0.26 W/m\({}^{2}\)K was assumed for the green roof. Data concerning the windows and their general dimensions are summarized in Table 3.  
The initial temperature and relative humidity were set at 20 \({}^{\circ}\)C and 70% throughout the construction, respectively. The thermal resistance of the interior was set at 0.13 m\({}^{2}\)K/W while the wind-dependent surface resistance coefficient was set for the external side (as described in Section 2.3). The internal loads were defined according to the value proposed in DIN 18599-100 for hotel room activities and in DIN 1946-2 for hotel bathrooms, according to the schedule reported in Figure 5.  
Different input data were defined for the summer and the winter seasons concerning air infiltration. The infiltration rate for the summer conditions was 2 ach (air changes per hour) from 22:00 to 08:00 and 0.5 ach for the rest of the day; simulations were run with and without an ideal HVAC system for cooling and with a temperature set-point of 26 \({}^{\circ}\)C. The infiltration rate in the winter season was 0.3 ach (air changes per hour). No mechanical ventilation system was provided. An ideal HVAC system was considered for heating, with a set-point temperature of 20 \({}^{\circ}\)C. The operative temperatures were evaluated  
Figure 4: Axonometric view of the room.