The demand of a new generation of public services is leading to a systematic exploration of what design can do for public organizations. The article presents and discusses, with the help of 2 design projects conducted in the Municipality of Turin, a design based theoretical framework for organizational change by conducting long terms process of engagement and exposition of employees from public sector to design culture. The 2 cases show as the raise of innovation capacity in public sector based on the practice of service design projects must consider the necessity of coping with long-standing challenges, ie the innovation of public bodies; the peculiarities of organizational learning processes and of the absorptive capacity of the organizations; and the overall resistance to change in people and organizations instead of trying to circumvent them.