Architectural design is regarded as what can be rendered as a text, and the starting point for its study are the written traces, the first records of architectural thought in the form of lines and words. In this way, a special text, iconic as well as verbal, is circumscribed, the design text, whose semiotic economy we shall explore. Instead of the standard distinction between depiction and verbally articulated expression as two fields which, by definition, oppose each other, for architectural design iconic and verbal signs are elevated to a unit of signification. Depicting in lines and putting into words represent two ways of enunciating the same gesture, the gesture of writing: they constitute the double writing of architectural design. The concept of the sign, as described by the German philosopher Edmund Husserl, is what allows for a conscious shift from the distinction between iconic and verbal signs to a joint approach towards them with regard to design text, irrespective of their material status. Design text points beyond itself and at something which is out there, rather than expressing its creator. Because of that, by assuming spatial dimensions, the written signs of the design text open up an – interstitial, as it will be argued– space, that of inscription, a space where writing prevails.