Synonyms of the word 
OPEN-PLAN → UNRESTRICTED
open-plan
- adj. (architecture) Having large rooms with few dividing barriers such as partitions.
unrestricted
- adj. not restricted or confined.
- adj. having no security classification.
If you are interested in words, visit the following sites :
- wiktionary.org/open-plan For complete definition of a word
- 1word.ws/openplan to play with words, suffixs, prefixs, etc.