## 6 Discussion  
Based on the results reported above for the three healthcare buildings, it can be noted that the construction year (or building age) tells a lot about the automation and control system installed and its functionalities and capabilities in Danish healthcare facilities. It is highlighted that newer buildings have, to a large extent, followed the recent guidelines and regulations in terms of systems design and automation and control units, while older existing buildings constructed years ago did not have the same technology and level of automation functionalities. In most cases, it can pay off to retrofit older buildings with newer technologies. Generally, the trend in Danish buildings retrofitting is to prioritize the envelope-targeting measures, as walls and roofs insulation and windows upgrade [38; 39; 40]. While such measures are important, dealing with the building systems and BACS design functionalities provide other options which in many cases have higher technical and economic feasibility. Such alternative measures could include the implementation of an EMS system, setting additional indoor comfort and air quality sensors, installing additional submeters for electricity, heating and/or other consumptions. Figure 13 provides a holistic comparison of the class scores for the different domains in the three buildings in the four considered scenarios, the base case, with technical improvements, comfort improvements and with energy efficiency improvements. It can be seen from the scores reported for the three cases in their base case scenario that Case A is scoring the lowest in the majority of the technical domains, except for electricity, where Case B scores the lowest. As mentioned, the reason behind Case B scoring low in electricity is the lack of locally generated electricity, and the absence of the corresponding storage units, as well as the possibilities of charging EVs. The low score of Case C in the dynamic envelope  
Figure 12: Results of Energy Efficiency Improvements Package in (a) Case A, (b) Case B, and (c) Case C.  
is interesting, compared, for example to an older Case B, constructed 19 years before. However, the reason is that Case B has undergone a deep energy retrofit, where smart windows were implemented, and sensors for open/closed detection for the windows/skylights were fitted in. Figure 14 presents a comparison of the total points collected by each building in the different scenarios against all the five impact criteria considered. Overall, all three cases scored very low in flexibility and storage caused by, among other domains, the domestic hot water, which indicates that this is an area where hospitals and healthcare buildings in Denmark need to provide more concentration on. This score is also affected by the legislative constraint of water storage, due to legionella bacteria. It is very well noted that while the three packages allow higher points accumulation and relative high score in the three cases, Case A is the one exhibiting the largest increase in the number of points accumulated due to the lower initial level of building automation and control in this case compared to Case B and Case C. On the other hand, it is obvious that the comfort improvement measure has improved the comfort criteria in the three cases by 14, five and five points for cases A, B and C, respectively. In addition, implementing the energy efficiency improvement package has led to a drastic increase in the number of energy efficiency points in the three cases, with an increase of 50, 10 and 17 points in cases A, B and C respectively. The current version of IBACSA tool used in this study aims at assessing the design and functionalities of the BACS along with evaluating the smartness of the building by focusing on 8 building domains from an energy and thermal comfort perspective. Moreover, five impact criteria are considered as a basis for the evaluation, including the two major criteria Energy Efficiency and Comfort.