Describe the interrelated configurations of physical elements and decision clusters that occur within a larger dependency hierarchy.

In Open Building terms, the Support constitutes a higher level, while infill is lower, dependent level: should the Support change, the infill is inevitably affected, although the infill can change without forcing change at the higher Support level.

Environmental levels include: the urban (tissue) level; Support (base building or building) level; infill (fit-out) level; and furniture (furnishings) level.