'unarchitectural' originates from English, formed by the prefix 'un-' (meaning 'not') attached to 'architectural', which in turn derives from 'architect' + the adjective-forming suffix '-al'. 'Architect' ultimately comes from Greek 'arkhitektōn' meaning 'chief builder'.

'arkhitektōn' (Greek) passed into Latin and Late Latin as 'architectus', then into Old French as 'architecte' and Middle English as 'architect'. From 'architect' the adjective 'architectural' developed in English; the negative prefix 'un-' was later attached to form 'unarchitectural'.

Initially, 'arkhitektōn' meant 'chief builder' in Greek; over time the root evolved to refer to a designer of buildings and to the qualities of building design. 'Unarchitectural' later emerged to denote the absence of those architectural qualities.