Principles of design composition are commonly understood to pertain to geometrical systems for arranging parts in assembling a formal whole. Connection to socio-cultural 'meaning' and relevance arguably occurs primarily via the assumed divinity or universality of these systems. In the contemporary architectural world, where explicitly held beliefs in fundamental, geometrically defined principles or values have dissipated, guiding principles of composition appear to be obsolete. This seems particularly true in relation to work that highlights process - or change, responsiveness, interactivity and (...) adaptability - since this implies that the composition remains in flux and unable to be grounded in the composition of form. While processually inflected architecture (referred to here as 'processual architecture'), has been an active field since at least the 1960s, it has been significa ntly developed since design experiments involving digital computation intensified in the 1990s. For this field of work, both highly celebrated and criticised as superficial or unethical, any connection to 'meaning' or value that might be offered by principles of composition would appear especially lost. This thesis reviews, counterpoises and reorients these assumptions, arguing a case for the value of processual architectural that has not been previously articulated. After the last 10 to 15 years of digital experimentation, it is clear that digital technology in itself is not the primary issue, but simply part of a complex equation. The thesis articulates this 'equation' through the model of emergence, which has been used in the field with increasing prominence in recent years. Through both practice-based research and theoretical development, a processually inflected theory of composition is proposed. This offers pathways through which the potential of processual architecture might be productively developed, aiming to open this field of work into a deeper engagement with pressing contemporary socio-political issues. The thesis demonstrates how the cultivation of particular modes of attention and engagement, found to hold an implicit but nevertheless amplified significance within processual architecture, make it possible to develop an embodied awareness pertaining to an 'ethico-aesthetic know-how'. This know-how is acquired and matured through attention to the affective dimensions that arise through design activity. The thesis highlight aspects of design process and products that are routinely suppressed in architectural discourse, generating new insights into the importance of affect for design process, design products and the relations between them. The ethical dimensions of such an approach become especially poignant through the explicit connection made between design activity and the practices of everyday life. Relationships between architecture and the social become re-energised, in a radically alternative manner to the social agendas of modernism or the more literary critiques of post-modernism. Through detailed discussions of the specific, local conditions with a series of design projects I have undertaken, I argue how and why close attention to the affective dimensions of design process offers new and productive ways to approach research through design practice. This offers a response to the calls for new 'post-critical' forms of research through empowering both sides of a previously held divide: theory and practice. (shrink)