Amidst escalating costs and inefficiencies in the construction sector, driven by challenges such as affordability barriers for sustainable practices, limited scalability of green technologies, and gaps in integrating sustainability metrics into architectural design processes, there is a critical need for transformative strategies. This research proposes a strategic approach that harnesses Building Information Modelling (BIM) and prefabrication to overcome these challenges while focusing on enhancing architectural outcomes. Through qualitative analysis comprising a contemporary literature review and simulation of BIM and prefabrication in the context of a specific case study project in New Zealand, this study explores the collaborative potential of these technologies to enhance architectural excellence in sustainable construction. The effective integration of BIM and prefabrication can streamline project schedules and elevate architectural design processes. This collaborative synergy emerges as a catalyst for sustainable construction, promising significant improvements in architectural qualities. Architectural quality has vast dimensions, and this research has examined it from the perspective of project costs, building safety, project scheduling and energy efficiency. By systematically reducing project overheads and prioritising occupant well-being and safety, this research advocates for the widespread adoption of BIM and prefabrication in public sector construction, heralding a paradigm shift towards industrialised construction methods. The research results show that integrating prefabrication and BIM can reduce construction costs, prevent wastage of materials and excessive energy consumption, reduce project execution time, prevent rework, increase safety, and ultimately improve Architectural excellence.