This paper examines the action research cycle of the first phase of a longitudinal research on sustainable interior design practices, between two groups of stakeholders, designers, and clients. During this phase of the action research, the first step - 'Unfreeze stage' - of Lewin's Change Management Model (1943), has been utilized towards the aim of creating a felt need for change among the participants. Affective domain learning theory, 'receiving and responding' (Krathwohl, D. Bloom, B. and Masia, B. 1964) is utilized to attain the 'Unfreeze stage'. 'Receiving and responding' is explained as: be open to experience, willing to hear, attend and react to particular phenomena, in our case, sustainable interior design practices. These are the objectives of the first phase of the longitudinal research. Traditional learning with the use of IT and experiential learning are the learning methods that have been implemented towards the acquisition of the objectives. Learning methods, objectives and aim, requisite the design of interventions with participants' involvement in activities that would lead to the acknowledgment of the benefits of sustainable practices. Interventions steered the measurement of interest in session, enthusiasm display, interest in learning, participation, and interest in the outcomes. The data collection methods that are used in this action research are: observers' report, participants' questionnaires and interviews. The data analyses use both quantitative and qualitative methods. The main beneficial aspect of the quantitative method was to provide the means to separate out a large number of factors that obscured the main qualitative findings. The qualitative method allowed data to be categorized, in order to adapt the deductive approach, and then examine for commonalities that could reflect relevant categories or themes. The results from the data indicate that during the first phase, designers and clients' participants altered their behaviours. According to affective domain, and through 'receive and respond', the objectives of the research have been attained, and therefore the felt need for change, thus the Unfreezing stage, have been accomplished.