Post-independence architects of Sri Lanka practicing after 1948 reinterpreted outdoor transitional spaces such as verandahs and courtyards integral to traditional houses, which were multifunctional living and circulation spaces that created physical and social interactions and thresholds. This paper considers four selected precedents: two case studies of single-unit urban house designs of pioneering Sri Lankan architects with modernist influence as examples for 1950s and 60s houses in comparison with two case studies of traditional house types. The study explores the change in spatial patterns through graphical analysis of plan forms to understand the shift in socio-spatial role. In post-independence Sri Lankan modernist houses, the multifunctional role of semi-outdoor spaces common to traditional houses changed to a single function in most spaces with fewer connections to other living areas. Outdoor spaces, previously free and undefined, were incorporated in the house with designated functions from gardens to lightwells to utility. Compared to the traditional typologies, the modernist influenced urban house examples exhibit a considerable change in spatial patterns affecting the socio-spatial role of outdoor transitional spaces.