Glossary

Floor-to-Floor Height (Slab-to-Slab Height)

Also known as: slab-to-slab height

The vertical distance from the top of one floor's structural slab to the top of the slab above it, which determines how much space is available for raised or accessible flooring, ceiling plenum, mechanical distribution, and finished ceiling height combined.

Floor-to-floor height is a fixed structural dimension set at original construction and effectively impossible to change afterward, which makes it one of the most consequential and least flexible variables in evaluating a building's competitiveness and conversion potential: modern trophy and top Class A towers are commonly built with 13- to 15-foot floor-to-floor heights specifically to support the finished 9- to 10-foot ceilings, generous ceiling plenum for large HVAC ductwork, and raised access flooring that data-intensive and trading-floor tenants demand, while older buildings with 11- to 12-foot floor-to-floor heights struggle to offer competitive finished ceiling heights once modern mechanical, cable tray, and sprinkler distribution are threaded through the plenum. In laboratory conversion analysis, floor-to-floor height is treated as close to a hard gating criterion rather than merely a preference, since lab mechanical distribution consumes so much more plenum space than office systems that buildings below roughly 13 to 14 feet floor-to-floor are generally excluded from consideration regardless of other favorable characteristics.