Modular construction offers significant advantages over conventional building methods, including reduced construction time, minimized waste, and improved quality, making it particularly suitable for applications such as emergency housing and temporary buildings. Recent developments have shifted the focus of modular building design from Design for Manufacture and Assembly (DfMA) toward broader lifecycle-oriented strategies such as Design for Adaptability (DfA) and Design for Disassembly (DfD). This study reviews current literature on these approaches and examines their integration with digital technologies, particularly Building Information Modeling (BIM). Key findings highlight principles that underpin adaptability and circularity in modular buildings, including a parametric study toward reconfigurable product optimization. A parametric modeling framework is presented that demonstrates how optimization processes can extend beyond manufacturing and assembly to encompass adaptation and disassembly simulations. A flat-pack modular building case study illustrates the application of this method, highlighting the potential of Design for Adaptability and Disassembly (DfAD) in reconfigurable modular building design.