ABSTRACT The main figure in this thesis is Aldo van Eyck. Apart from the interest he aroused throughout his professional career and the influence of his particular personality, the main incentive for this present research is to approach his vision into the relationship between ‘architecture’ and ‘society’ or, more specifically, on how architects can (and must) introduce significant improvements in people’s ways of life (or users’ ways of life). In other words, this thesis aims to analyse Aldo van Eyck’s concept of the human dimension of architecture. Already in the introductory chapter, the ‘human dimension of architecture’ was defined as the conscious way in which architecture considers the interaction with its future users, with a clear goal to develop designs concerned in improving their lives. According to this definition, there are several key terms. On one hand, the words “conscious” and “considers” denote that there is a deliberate and voluntary reflection on the identity of the user in architecture, as a result of a previous concern or interest in the topic; in this way, one can understand that if this is not the case (this conscious awareness) we will hardly refer to it as ‘human dimension of architecture’. And on the other hand, the word “interaction” proves that there is an exchange, a return trip between architecture and its users, so that the architect gathers information about their features and requirements through his observation and personal reflection, with the aim of developing designs to enable them to improve their lives. That is to say, without underestimating the success achieved by a particular architectural design, it is the purpose and commitment to the future users that has originated the topic exposed here; i.e. the ‘human dimension’ concept developed (or not) by one architect means above all a question of attitude. Therefore this special and specific sensitivity, subject of the analysis, starts when the architect (albeit unconsciously) takes it into account; when he aspires to influence in the best possible way the lifestyles of users. The main hypothesis of this research is to assume that the ideas and principles that characterized Aldo van Eyck’s thought (more specifically those aspects related with his concept of the human dimension of architecture) should determine his whole work, in a conscious manner through his writings, and influencing more unconsciously or intuitively in his designs. Thus, one of the main objectives of this thesis is to prove if this aspect of Aldo van Eyck’s architectural thought pervaded both facets and practices of his professional activities, which apart from affecting his general working method, is reflected in the title and subtitle (“Written” and “Built”): once the key to how van Eyck understood the human dimension of architecture has been identified through his writings, the aim is to recognise its influence in form of one of his most outstanding projects. In other words, in respect to his writings, the methods used should be considered as one (readings and studies of his original texts) with the aim to research this particular descriptive aspect of his architectural discourse –—all of which is evident throughout the first five chapters—. And in respect to his buildings, and taking as an example one of his most relevant projects (the Pastoor Van Ars Roman Catholic church), the strategy is to identify how van Eyck put into practice his concept of human dimension of architecture. Thus, basically from the original information and the testimonies gathered in the Netherlands during 2011 and 2012, and by means of the detailed architectural study carried out on the building (arranged in six main chapters), it is shown how Aldo van Eyck’s concept of human dimension of architecture determined the design and construction of this project.