Mass timber products like glulam and cross-laminated timber(CLT) can store / sequester carbon in building stocks for as long as the building components remain in use. For this carbon reduction to have a significant impact, mass timber products must not release the carbon emission back to the atmosphere in their end-of-life. The end-of-life options for wood products are often reduced to landfills, energy production, reprocess, and recycling facilities. Most buildings with mass timber components are not designed for their reuse or reconfiguration. This thesis is investigating mass timber building systems' design for reconfiguration, exploring joinery types, structural elements compositions, timber section areas, and steel connections. A qualitative research method is used to refine the joinery design in different aspects of buildings. This study proposed innovative joinery solutions that increase mass timber reliability and design specification for mass timber building systems. For the purposes of the prototype described in the thesis, a full-scale model was built to examine the constructability of the reconfigurable joinery.