open-plan

UK: /ˌəʊpənˈplæn/

Collins Concise English Dictionary © HarperCollins Publishers::

open-plan adjective

1. having no or few dividing walls between areas: an open-plan office floor

WordReference Random House Unabridged Dictionary of American English © 2025

o′pen plan′, 

1. Architecture a floor plan without fully enclosed spaces for distinct rooms. Cf. closed plan. 

• 1935–40

o′pen-plan′, adj.