The evalution of interactions between transparent surfaces in street interfaces and urbanites: Case study of Bagdat Street

In the present-day cities' buildings which are public and non-private, it can be clearly observed that facades, especially ground floor facades are typically designed using glass. This usage is more prominence on the facades of shops which take place in public spaces. When the facades of these shops which can also be defined as private spaces are analyzed, it is observed that there are two types of sections according to relation of glass with other façade elements. At the first section, there are generally opaque backgrounds in front of which products are presented at the back of glass surface or though there are no backgrounds, there occurs the feeling of opaqueness as people focuses on products rather than two dimensioned visual background created by space. The main purpose of these façade parts which are called as showcases are to present products and for that reason, they are important for shops. At the second section, there are neither backgrounds nor products at the back of glass surface. The main purpose of these façade parts which are called visually permeable surfaces are to provide the feeling of inviting and to found visual connection between public and private spaces. When academic studies about glass and transparency are examined, it can be easily seen that transparent ground floor façades effect public spaces in a positive manner. But transparency descriptions in those studies do not involve differentiations between two section types which are mentioned above. Especially at that point, it is important how showcases are evaluated by urbanites as they may be evaluated as transparent or opaque according to variable parameters like sight physiology, distance, section properties. What is aimed at that point is to realize a study which tests the affects of transparency on urban spaces and urbanites by taking section differentiations -especially showcases- into consideration. In this context, interaction of urbanites with ground floor façades which can also be defined as 'street interfaces' is studied over the notion of transparency. Therefore first, humans' perception of environment is studied over sense of sight because sight is primary sense organ among the others. That perception process which starts by seeing ends when urbanite that interacts with facade decides and acts about facade according to qualities of it. This action may be to view façades, to move towards them or to realize any action in front of them. In such decisions of urbanites, qualities of interfaces are important because elements of them have the potential of effecting urbanites. That's why in the next phase of the thesis, architectural elements of ground floor façades are studied. What is important here is to focus on ground floor level of interface rather than whole interface as urbanites move in public spaces, they see those levels due to sight angles which human has gained after evolutionary processes. Also, the points where interaction between buildings and urbanites occurs are those levels. This study is realized by taking sight process into consideration as thesis is based on that sense. In that context, a classification is done according the relation of light with human eye and objects in environment as sight realizes thanks to light. Regarding to this classification, urbanites perceive the elements that ground floor facades have according to their shape, texture, pattern and their opacity, translucence and transparency. Transparency is among all those elements in the context of shops as presentation of products is important for such type of places. Also, visual connection which is provided between shop and urban space where the shop faces extends the boundary of interface. That's why, the shop's space works as an extension of the urban space. After literature search, the factors which have a role on interactions between urbanites and interfaces are indicated and a field study has been realized by taking those factors into consideration. Hereunder, eight shop facades that take place in Bagdat Street, which have different ratios of showcase areas and visually permeable surfaces are chosen within some criterias. The main method of the work is based on observing the movements of urbanites in front of those facades. With that observation, numbers of urbanites that look and move towards facades are counted and after all this data is compared with transparency ratios of facades. By this way, it can be seen that if change in transparency ratios affect the movements of urbanites or not. Eventhough it is purposed to eliminate the effects of other elements except transparency, some of those can not be eliminated due to some qualities of shops' facades in study field. To evaluate the effects of those elements, a survey is conducted with urbanites that move towards facades. The data which comes from the survey is used as assistive when transparency ratios are compared to the movements of urbanites. According to the results of the work, when the ratio of all glass surfaces on a façade increases, the number of urbanites which heads toward façades decreases and the number or urbanites which looks to façades slightly increases. This situation can be explained firstly by the ratio of showcase areas' being higher than the ratio of visually permeable surfaces in all façades because this situation provides more products to be presented and more urbanites look at those thanks to that. Secondly, ratio of visually permeable surfaces in all façades with the tendency of being constant causes all façades to have same inviting ratio. Because of that, the number of urbanites that head towards façades does not change. So, when all this information is evaluated together, it is observed that showcases should be defined as opaque façade parts although they perceived as transparent when looked from urban space. When differentations of sections are examined apart from each other, similar results are taken. Hereunder, when the ratio of visually permeable surfaces of a façade increases, urbanites perceive façades more inviting and more spacious. Similarly, when the ratio of showcase areas of a façade increases, it is seen that urbanites are in more interaction with products and showcases. Besides, when answers of questionnaire and exceptional datas of countings are examined, it is seen that brand which can be defined as a different element rather than the ones based on perception is an effective component in interaction process mentioned above. Because, answers to questionnaire questions that measure brand effect are included in the score scale defined by the researcher as 'effective' and 'very effective' and despite the low inviting ratio of the façades of popular stores, they attract many urbanites. As a result, it is a must to design facades with more showcases when it is a will to catch the attention of urbanites about products. Contrariwise, it is a must to design facades more visually permeable when it is a will to exhibit the space. At that point, it may be asked that at what ratios those two section types should take place in façades to catch maximum attention of urbanites, but the purpose of the thesis is not to find that ratio. To reach such ratio, a model which takes the weighted effect of both section types into consideration and involves façades that all parameters except transparency are constant may be developed. With such model, further works which are at higher levels may be realized about the notion of transparency.