intangible architecture . . .

intangible |inˈtanjəbəl|
adjective
unable to be touched or grasped; not having physical presence: my companions do not care about cyberspace or anything else so intangible.
• difficult or impossible to define or understand; vague and abstract: the rose symbolized something intangible about their relationship.
• (of an asset or benefit) not constituting or represented by a physical object and […]