Built in 2008, 柏林爱乐 Bolin Aiyue or the Berlin Philharmonic residential complex at the East of Beijing, is composed by thirty-eight buildings from six to twenty floors with thousands of residents of diverse social classes. These utilitarian structures, with massive forms and lack of decorative details, characteristic of Chinese modern architecture, may seem impressive at first sight as when I arrived to Beijing in October 2017. Since then, I have lived in Bolin Aiyue, which makes it the first site to put in place this windows’ project. As the title expresses it clearly, windows are the central shape to be photographed, as they connect the inside and the outside world in ways that I will attempt to study. As the philosopher and urban rhytmanalyst Henri Lefevre puts it, ‘the fact is that the window is a non-object which cannot fail to become an object. As a transactional object it has two senses, two orientations: from inside to outside, and from outside to inside’ (1991: 209). Therefore, I propose to explore and classify these orientations in six chapters, where the relation between the observer and the observed, whether these are windows or what is seen from them, are the constants that give a common thread to the project’s experimentation and reflection stages. In these six chapters, artists references are commented and visual experiments are put into practice, starting with the most mobile and common of observations, when walking inside the residence and looking at windows from outside. The other chapters are rather settled in one space, my apartment, and its surroundings, which reduces the range of the study, unless one considers the distant view from my windows. Finally, the last chapter is the most complex as it involves four of my neighbours and their windows. The project that one starts alone in his apartment scales up by being shared with others, as windows of Bolin Aiyue, or windows in general, concern us all.