There is often wide disagreement about the significance of–and need to preserve–upper-floor corridors in historic tax credit (HTC) developments. Upper-floor corridors were frequently utilitarian in older buildings. They were formed of hollow clay tile with a flat plaster finish. Floors were often terrazzo, though sometimes marble, with a marble or wood base.
![](https://heritage-consulting.com/wp-content/uploads/2015/10/Novogradac_Journal-of-Tax-Credits_October-2015-Issue_pg67-1.jpg)