In this paper, we propose a novel methodology to guide and assist practitioners supporting software architecture and design activities in agile environments. Software architecture and design is the skeleton of a system. It defines how the system has to behave in terms of different functional and non-functional requirements. Currently, a clear specification of software architectural design activities and processes in agile environments does not exist. Our methodology describes in detail the phases in the agile software design process and proposes techniques and tools to implement these phases.