Indoor-outdoor visual connectivity studies focus on analyzing view vectors and their spatial distribution, considering the three-dimensional nature of visual perception. Typically, these studies use the observer's position as a focal point from which view vectors radiate outward. However, they often overlook the multiple positions an observer can occupy in space and the various relationships these positions create with the façade system, leading to differing visual connections to the outside environment. Specialized studies that analyze multiple observer positions provide valuable insights by mapping visual connections for each location. However, they tend to lack a singular metric to assess indoor-outdoor visual connectivity as a factor influencing visual performance in relation to the space and façade system.

This article introduces the Visual Connectivity Index (VCI)—a metric designed to evaluate indoor-outdoor visual connectivity. VCI measures the relationship between a façade system and the indoor space it encloses, assessing how uniformly and seamlessly the interior connects to the exterior through the façade system while considering multiple observer positions. VCI contributes to three key areas: (1) It enables the evaluation of a façade system’s impact on visual connectivity and its interaction with enclosed space; (2) It provides a performance-based measure of visual connectivity (3) It facilitates the comparison of alternative design solutions within the framework of architectural design.

By synthesizing the complex phenomenon of indoor-outdoor visual connectivity with the role of the façade in shaping this relationship, Visual Connectivity Index (VCI) presents a novel and valuable approach that has not been previously explored. To demonstrate its application, this study systematically compares the performance of 20 design alternatives across three different façade systems, resulting in a total of 60 iterations. The results indicate that VCI is sensitive to various design options, enabling a thorough evaluation of different architectural design choices. ... Read more

In recent years, several studies have assessed the influence of automated façades on energy savings, IEQ, and occupant satisfaction. However, discrepancies exist between the expected advantages of automated façades predicted in research and the actual benefits observed in real-world tests. To assess how automated façade operation enhances building performance, in particular within office building contexts, this study reviews and analyzes current evidence on the influence of automated façades. In this review, 91 studies were identified presenting evidence of their performance. A total of 34 studies investigated performance in laboratory settings, 23 in real office buildings, and 34 in simulations. Only 13 laboratory studies and 17 real office building studies included human participants. Visual and thermal quality were the main indoor environmental domains investigated, with limited exploration of others. Existing studies show large variability in contextual factors (e.g., type of shading and control) or experimental designs (e.g., different benchmark scenarios), hindering the comparison of results. Consistent evidence shows the potential of automated façades for energy savings, particularly in lighting and cooling demands, which outperform manual control systems. Automated controls are more effective in reducing excessive daylight and glare, while evidence of the impact on thermal and air quality remains limited. Regarding occupant satisfaction, evidence is unclear since, in some cases, occupants prefer manually controlled façades and, in others, automated ones. Further research is suggested on human-centered studies in real office buildings to capture occupant behavior and preferences while exploring solutions that dynamically identify and integrate factors affecting occupant interaction with buildings. ... Read more

Background. The automated operation of facades in buildings can positively impact indoor environmental quality (i.e. thermal regulation, acoustic control, air quality, and access to daylight and outside view) whilst reducing cooling, heating, and lighting energy demand. Conversely, several studies have also pointed out that the automated operation of dynamic façades can be disruptive to occupants and a source of discomfort when it does not meet occupant requirements. A number of factors affect occupant requirements regarding façade operation. However, the preference with which individual occupants perceive these requirements, in particular window visual effects, is yet to be understood, and it could inform better user-centred controls of automated facades. [...] ... Read more

Several studies performing building simulations showed that the automated control of façades can provide higher levels of indoor environmental quality and lower energy demand in buildings, in comparison to manually controlled scenarios. However, in several case studies with human volunteers, automated controls were found to be disruptive or unsatisfactory for occupants. For instance, automated façades became a source of dissatisfaction for occupants when they did not fulfil individual environmental requirements, did not provide personal control options, or did not correctly integrate occupant preferences with façade operation in energy-efficient controls. This article reviews current evidence from empirical studies with human volunteers to identify the key factors that affect occupant response to automated façades. Only twenty-six studies were found to empirically investigate occupant response to automated façades from 1998 onwards. Among the reviewed studies, five groups of factors were found to influence occupant interaction with automated façades and namely: (1) personal factors, (2) environmental conditions, (3) type and mode of operation, (4) type of façade technology, and (5) contextual factors.. Overall, occupant response to automated façades is often poorly considered in research studies reviewed because of the following three reasons: (i) the lack of established methods or procedures for assessing occupant response to automated façade controls, (ii) poor understanding of occupant multi-domain comfort preferences in terms of façade operation, (iii) fragmented research landscape, on one hand results are mainly related to similar contextual or climatic conditions, which undermines their applicability to other climates, while on the other hand the lack of replication within the same conditions, which also undermines replicability within the same condition. Lastly, this paper suggests future research directions to achieve a holistic and more comprehensive understanding of occupant response to automated façades, aiming to achieve more user-centric automated façade solutions and advanced control algorithms. In particular, research on the impact of personal factors on occupant satisfaction with automated controls is deemed paramount. ... Read more

Green screen façades (GSF) remain an unexplored field of study in warm-summer climates with Mediterranean conditions. This research aims to establish whether or not these thermal comfort façade systems are worth developing in cities with dry summers and a high range of thermal oscillation. A comparative study of four buildings´ green screen façades in Santiago de Chile was carried out, with different orientations and plant species, both in type and state of maturity. Temperature and relative humidity outside and inside the cavity were measured during summer days. It was observed that, during the day, interior relative humidity was higher while the temperature was lower, reverting this behaviour during the afternoon and night. This result accounts for the existence of two different daily periods: passive cooling through evapotranspiration in the presence of solar radiation - reaching up to an 8°C temperature reduction and a 30% increase of the relative humidity - and passive heating in its absence. The results show that the determining parameters in the behaviour of a green screen façade in a temperate-warm climate are, first, the orientation of the façade, and second, the density of foliage. Regarding orientation, it was also found that the sun exposure was directly proportional to the performance of a green screen façade. ... Read more

Since Kahn proposed the separation between servant and served spaces - transforming the former into the invisible infrastructure that allows the splendor of the latter - the distinction has remained valid as a design tool. But when servant spaces happen to contain the building’s own systems, such segregation becomes problematic: the building no longer relies on its own infrastructures, but these also require excessive energy. ... Read more