The MINIMUM finished height of access flooring in a general office area is:

50 mm (2 in) is far too shallow to provide usable underfloor space for cable trays, conduit, or airflow distribution in any practical installation.

150 mm (6 in) is below the 200 mm minimum threshold required by the standard for general office access flooring and does not provide adequate clearance.

The minimum finished height for access flooring in a general office area is 200 mm (8 in), as specified in building infrastructure standards such as the BICSI TDMM. This height provides sufficient plenum space beneath the raised floor for horizontal cable routing, power distribution, and airflow while still being practical for general office construction.

250 mm (10 in) exceeds the minimum for general offices and is more typical of environments with higher cable density or dedicated airflow requirements such as data centers.

300 mm (12 in) is well above the minimum for general office areas and is associated with high-density environments like data centers or large telecommunications rooms.