This study examines the effect of rent regulation on housing quality in Manhattan. In particular, this study investigates how a specific law change on rent increases due to home improvements in the Rent Act of 2011 affected the rental housing quality in Manhattan. Through combining multiple sources of data, including complaints received by the Department of Housing Preservation and Development (HPD) and the Department of Buildings (DOB) and building information scraped from NYC public databases, I construct a novel longitudinal dataset with identifiable information of each building and the number of complaints each building receives as a measure of housing quality. Using a combination of regression discontinuity and difference-in-differences, this study shows that the specific law change in the Rent Act of 2011 has a negative effect on the housing quality of the associated rent-stabilized buildings in Manhattan. While previous literature has not reached an agreement on how rent regulation affects housing maintenance and improvements, this study aims to contribute to this discussion with novel data and analyses.