Recently we have witnessed residential lighting features in Tehran which have caused visual turbulence in Tehran night landscape due to the absence of guiding regulations and the lack of public awareness from public lighting entity. This reveals the need for legislations to control this process. To establish regulating principals, a scientific understanding of the lighting in the city has to be fulfilled. In this regard, 50 samples of residential lighting in Tehran in the form of a study were carried out along with extensive field observations. Observations show that the general residential lighting features follow three main approaches including realistic performance, decorative as well as meaningful. In addition, taking into account the conceptual and visual criteria, the facades can be categorized in six groups with different characteristics.
The six categories present Tehran's six residential facade lighting styles that are running in parallel in the whole city. According to a sample survey, the most frequent style is the Roman classical lighting in different areas of the city. In the following building facades of the second and third category are more abundant in which designers have paid a greater attention to color and form attractions. Meaningful and selective categories contribute to a small percentage of residential sites in Tehran. Facades in which the lighting is used for instilling a sense of meaning or emphasizing on a certain concept do not have a strong position in night landscape of the city.
However, a cycle can be observed in lighting approaches. A cycle which begins with selective (having functional goals) approaches and after passing decorative approaches ends up with the same selective lighting approach in order to express the meaning and particular purpose and aesthetics rather than function focuses.
Nevertheless, the decorative use of lighting in residential buildings and a large variety and inconsistency of the lighting of the environment has led to visual inconformity. Categorizing lighting approaches and recognizing theoretical aspects and characteristics of each of these categories can be considered the first step in management and regulations of night landscape of residential neighborhoods.