Innovation is widely recognised as a driving force for a firm's economic growth. Generally, innovation can come to an organisation by means of adoption or generation. Either way, the process of innovation diffusion is involved. Diffusion is a process by which an innovation is disseminated through communication channels among members of a social system over time. In this regard, social influence, in terms of organisational climate, is conceived of as a critical innovation enabler. This paper thus focuses on studying the impacts of a facet-specific climate namely "climate for innovation" on innovation diffusion outcomes in architecture and engineering design (AED) firms. This paper argues that there are three main factors forming climate for innovation: organisation culture, leadership and team climate. Despite the existing literature within the context of construction highlighting the importance of such factors, empirical studies addressing their impacts on firm-level innovation diffusion and business performance are sparse. To overcome this deficiency, a conceptual model was developed to be used for empirical investigation. This paper details the theoretical development of such a model and outlines a research method and plan of future research activities.