On one customary view of architectural objects, individual built structures (or their abstract counterparts) represent the primary unit of our aesthetic or, for that matter, any architectural, concern; all other ways of carving up the architectural world are derivative.  This view is consonant with an equally customary perspective identifying architectural objects with architectural works.  Alternative views include a “mereology”, in which parts of built structures (or their abstract counterparts) constitute independent architectural objects; and an environmental contextualism, in which collections of built structures (or their abstract counterparts) constitute independent objects. Both alternatives share a commitment to some form of compositionality among architectural objects, that putting bits together yields aesthetically meaningful and utility-bearing composites, and taking them apart yields like results. In this, the mereological view represents a downward-compositionalism, suggesting that architectural aesthetics demands our focus on structural or other elements that can be meaningfully distinguished. Environmental contextualism represents an upward-compositionalism, suggesting that architectural aesthetics cannot be pursued entirely separately from the aesthetics of cities or towns (per Scruton 1979/2013).