What is a deconversion? A deconversion is the process in which the owners of a condo building sell their units simultaneously to an investor, who then turns the property into an apartment rental building. If your condo is in an older building (built before the 1960s) chances are it was a rental apartment before it was a condo. During previous real estate cycles, condos were in high demand. So owners of apartment buildings converted the units into for-sale condos. Now, high re