||The increased density of many metropolitan areas combined with a trend toward shrinking household sizes is creating an increase in the demand for urban apartments. This increased demand has had a significant impact on the affordability and availability of housing in urban centres globally. The creation of smaller, denser units in the form of the micro units is one attempt to meet this need. Throughout the early 20th century, small studio apartments paired with poor building standards caused major health concerns and some opponents fear micro units will result in a return to such standards. This indicates a lack of knowledge about micro units. Micro units are compliant with building codes and are developed with the idea that the individual unit includes shared amenities with other residents. Opponents also claim that such apartments have negative effects on their occupants, on unit affordability in the adjacent area and lead to gentrification of traditional neighbourhoods. However, these claims are unfounded as very little research has been done on micro units. In most markets, micro units are a new typology for apartment housing and there is no evidence to indicate that such developments would have any negative impact on residents, neighbourhoods or pricing. Currently, several cities, such as New York, San Francisco and Singapore, are developing regulations related to micro units in their jurisdictions; these are in many respects different from one another. As there is no significant knowledge exchange among the planning departments of these cities, local governments, property developers and investors, and small urban households are beneficiaries of this study. This thesis identifies and analyses the intentions of involved stakeholders in three international cities, each at a different stage in its implementation of micro unit legislation and development, as well as its perception of whether micro units will satisfy the needs of a demographically changing urban population. The three case studies evaluated for this thesis include: New York (pre-development of legislation and micro units), San Francisco (legislation developed, micro units in development), and Singapore (units developed, currently re-assessing legislation). Interviews, site visits and additional material collected in these locations serve as primary data sources to explain recent development decisions on micro units. A cross-case report identifies similarities and differences in the three cities and contributes to the resultant implications for policy makers and practitioners. For policy makers, the research supports the development of zoning regulations identifying minimum apartment sizes; for practitioners, the research offers guidance to assist with development decisions on micro units. In addition, the thesis indicates that micro units are a feasible option for metropolitan centres to provide safer, more affordable, and suitable housing for small households. Finally, as interpretations of the term ‘micro unit’ differ significantly, this thesis provides a comprehensive definition of the term.