The City of Calgary is undertaking a multi-year development of a Complete Streets Guide. This initiative has a comprehensive guiding Project Charter and is governed by a City Steering Committee made up of senior managers. The main objective of the Guide is to provide a selection of multi-modal streets for both ‘greenfield’ and ‘brownfield’ development, and a process to implement them, with the goal of increasing the attractiveness, convenience and safety of all urban transportation modes. The Guide is intended for the use of both City staff and of the very active residential/industrial/commercial development industry in Calgary. The basic notion of ‘Complete Streets’ (as compared to the traditional auto-centred design standards) involves a much higher degree of complexity in design and potential for stakeholder involvement, and may involve greater per-metre costs and cross-section widths for streets. The focus on encouraging ’Active’ mode use and transit, combined with the soon-to-bemandatory (in Calgary) incorporation of Low Impact Development (LID) measures into most street cross-sections, requires a delicate balance of the needs of the various users and facilities competing for space within the right-of-way. In addition, the Guide’s intent to provide flexibility in application of the palette of new street standards is in contrast to the traditional ‘prescriptive’ approach. The paper describes D.A. Watt’s involvement, as the consulting extension of the City’s technical team, in the Complete Streets process. It addresses key aspects of the 2011 work scope, such as the survey of Winter Cities’ practice, development of recommended values for key (Critical) cross-section elements (e.g., driving lane, sidewalk and Multi-use Pathway, cycle lane widths), and development of the design documentation (text, road/intersection figures, spreadsheets) for Base and ‘Alternate’ cross-sections. A discussion of the key issues and ‘trade-offs’ (e.g., reduced driving lane width but increased minimum sidewalk width) is included. The impact and influence of shallow utility suppliers and developers is integrated into the process of design development. The paper also addresses the process, with internal City and ‘external’ stakeholders, by which the new standards and practice were developed. Finally, the paper touches on the ‘lessons learned’ and how other agencies may benefit from the Calgary experience.