In a 2009 interview, architect Peter St John of Caruso St John Architects defined a good architect as one who makes few compromises, highlighting precise instructions as imperative in achieving this. An architectural project, St John stated, 'is far more likely to work well if you put an enormous effort into defining what you want, to achieve quality’. At Caruso St John Architects' 2006 entrance addition to the Victoria and Albert Museum of Childhood in Bethnal Green, London [1], the precise specification of mortar and mastic joints throughout a cut-stone facade was employed to define expectations of quality in the constructed facade. These specifications, written in accordance with the recommendations of professional practice, set out stringent expectations of dimensional perfection. When dimensional variations during design development and construction threatened to disrupt these expectations, the precise definition of quality shifted, becoming less defined by dimensional perfection and more reliant upon the ‘architectural intentions’ underpinning the project. In referencing conceptual, ideological, historical and technological intentions which were difficult definitively to express, this critical phrase – ‘architectural intentions’ – is examined here in terms of its ambiguity in the context of the written specification [2].

Ambiguity in the written specification is emphatically rejected by regulatory and advisory bodies in the architectural profession, which frequently advise that the written specification must provide, above all else, certainty. In The Architects' Journal in 1989, author Francis Hall went as far as describing the properly drafted specification as the ‘one certain opportunity’ for an architect to set down a ‘definitive and enforceable expression of standard and quality’. ‘Properly drafted’ is typically translated as a prosaic language, specifically devoid of poetic content. The ability of the unambiguous written specification to convey adequately the poetic content of architectural intentions has, however, been under critique since its inception.