## 5 Calculating the MUA's Energy Demand  
Spanish regulations on energy efficiency in buildings make it compulsory to fill out the technical document DB-HE on energy saving [31; 32], which is part of the Technical Building Code (or CTE by its Spanish acronym). The regulation requires you to apply the standardised tool Lider-Calener (HULC) [33] to architectural projects. The tool models the project and applies a climate file, incorporated in the tool, depending on the location and altitude of the building site. You can obtain the annual energy demand value by simulation, and the energy rating according to the air conditioning systems and energy sources used in the building. This tool is a breakthrough for energy efficiency improvement. Nevertheless, it is still far from providing a simulation adjusted or calibrated according to buildings' actual behaviours. It also presents some shortcomings. For example, it does not allow to introduce bioclimatic techniques, or take into account the fact that certain energies are used predominantly over others, due to energy policies that are often not sufficiently justified [34]. Compared to HULC, other simulation tools such as Design Builder or TRNSYS allow adjusting to actual building use, such as opening or closing windows according to time slots or using the enclosures' thermal inertia for thermal comfort and reducing energy demand through phase change materials [35]. The Design Builder tool has been used for this research. Its reliability through the use of the EnergyPlus calculation engine has been extensively tested. To perform the MUA's behaviour simulations in terms of annual energy demand and control of interior comfort parameters, the building was modelled (Figure 8), and the following data was introduced into the Design Builder tool:1. The winter period covers 1 December to 30 April, and summer covers 1 May to 30 November These are the usual weather conditions of San Vicente del Raspeig (Alicante) where the University of Alicante is located. 2. The temperature of indoor air is 21 \({}^{\circ}\)C in winter and 24 \({}^{\circ}\)C in summer. Relative humidity (RH) remains at 50%. 3. Occupancy, for the standard calculation of air renewal, is 709 people, 0.5 people per m\({}^{2}\). According to current Spanish Technical Building Code (CTE) regulations, a value of 2.5 acH is required for air renewal, with 12.5 l/s per person. This high value was adjusted to the model calibration in Design Builder, with an average real occupancy of 100 people during visitor peak times, resulting in an air renewal of 0.36 acH. The energy demand was thus adjusted to the MUA's actual energy consumption. 4. Air infiltration through the enclosure was high, although it was moderated thanks to the application of continuous polyurethane foam during the MUA rehabilitation in 2010. As indicated, the quantification was performed thanks to a comparison with the Blower Door test carried out in similarly constructed buildings around Alicante [23]. The test was conducted in accordance with European Regulation EN 13829, using BlowerDoor GmbH MessSysteme Fur Luftdichtheit equipment (Figure 7). The adopted value was 0.864 acH. 5. We estimated load gains or losses due to thermal bridges at 3.5% of total thermal loads [28] by thermal transmittance \(U\) of the enclosures [27; 36], which were obtained on site by means of the multifunction instrument KIMO TM210 by Testo [37]. A ThermaCam P25 thermographic camera was used for detection and quantification. The schematic diagram of the capillary tube mats project was introduced into the Design Builder model (Figure 9). Several strategies were adopted to adjust the parameters obtained by simulation to the actual data, to calibrate the model. First, energy consumption data were obtained from electrical meters in the building. The surface temperatures of the TCP panels were then pre-set to 17 \({}^{\circ}\)C, to avoid surface condensation.