Accessory Dwelling Units: A Case Study in ROI and Housing Affordability in Tempe, AZ

My Barrett Honors Thesis focuses on answering the question of whether a current owner of a single family home in Tempe, Arizona would receive an adequate return on investment (“ROI”) to justify adding an accessory dwelling unit (“ADU”) on their property for the purpose of generating rental income and capital appreciation. I focused my research on Tempe’s zoning regulations, ADU general contractor (“GC”) options, possible parcels, proposed construction plans and budget, and lastly, a pro forma to determine ROI. After conducting the research, discussing with several GCs, and modeling returns, I determined that unlevered ADU development constitutes a novelty, not a solid investment choice with today’s market conditions. Factors that would change this recommendation decision would include a decrease in interest rates or a tempering of construction costs.