## 1 Introduction  
Climate change and global warming are no longer foreign words in the world today. Their affects are more complex than just climbing temperatures. The latest report from the climate change performance index (CCPI) [1] states that, still, no country is compatible enough with the agreed Paris agreement goals. The latest UN global status report [2] states that buildings contribute up to 39% greenhouse gas emissions. Out of these emissions up to 28% can be attributed to lighting, heating, and cooling alone. This implies that there is a great potential in optimizing the building performance with novel ways to make buildings carbon neutral. Though major inefficiencies in energy management are caused by the HVAC (heating, ventilation, and air conditioning) systems, artificial lighting also has a significant part in it. In 2020, electricity consumed by lighting is about 6% of total U.S. electricity consumption [3]. The benefits of daylight for building occupants are studied extensively in great detail in several studies [4]. They range from improved health and well-being to increased productivity [5]. However, designing daylight requires careful consideration of its integration into building control systems as it varies in direction, colour, and intensity over time. These variations are the design parameters that are difficult to cope with as they have a considerable impact on both the visual and thermal environment. A successful daylight design needs to accommodate the trade-offs and optimization between competing aspects such as choice of lighting, facade layout, and space configuration. This necessitates identifying the appropriate optical properties of the glazing system that provide adequate daylight while avoiding glare and undue heat gains. Shading systems such as electrochromic (EC) glazing have the ability to transition between different light transmission states with the application of little voltage. The transitions in EC glazing are seamless and it provides an unobstructed view during this process. EC glazing can also be divided into several zones and light transmission of each zone can be controlled separately, which gives it an inherent advantage over other shading systems as it can allow a high amount of useful daylight into the visual environment. Moreover, it is also known to provide effective sun protection reducing heating and cooling loads [6]. Designing a control strategy requires a deeper understanding of the problem [7]. In the context of EC glass, choosing the right set of variables for the control is important. A simple approach can be using the visual comfort parameters such as workplace illuminance and glare in choosing the right combination of EC glass. In this case, a simple ranking [8] of the combinations by maximizing workplace illuminance and minimizing glare would suffice, but there is a drawback to this approach. A better explanation for this would be possible with an example. Imagine a scenario where there is an option of electric lighting that can be switched on when there is not enough daylight in the workspace and also consider a situation where the EC glass is completely tinted to dark to avoid glare. In this case, the simple ranking strategy tries to increase the workplace illuminance by switching on the light and bring it to the comfortable range. In the meanwhile, if the sun is covered by clouds, the chance of glare is reduced. In this situation, would the occupants perceive the change in glare, since the EC glass is already darkened to prevent the glare and electric lighting is enough to keep the occupants in a comfortable range? More precisely would the sensors used for detecting glare and illuminance at the workspace be able to understand the external changes? Therefore this control would be stuck in the never-ending loop as it does not consider the external factors. Here the main drawback for it to be a control strategy is its lack of adaptation to the changing sky conditions.