Other ethical matters special to architecture are particularly visible in global perspective. For example, there is inequitable distribution of housing across the developed and developing nations, and part of the solution may be architectural (Caicco 2005).  Further, architecture incurs special environmental obligations given that waste and degradation affect, and are affected by, architectural design. One conceptual challenge of sustainability facing architects is to determine whether development is, in principle, a countervailing interest. This is to ask, once environmental obligations are defined, how they may be factored into or weighed against infrastructural and design interests and preferences.