Measuring the level of sustainability of a construction project is difficult when dealing with qualitative data and determining the most objective method for measuring such projects as defined by various stakeholders. The issue of judgment and interpretation remains difficult as it encompasses subjectivity and differing stakeholders' perceptions in assessment. This paper addresses sustainability assessment in regional shopping centres and develops a tool for architects, clients, producers and end-users to understand better building performance. This paper defines the potential problems of subjectivity in sustainability assessment arising from differing views of stakeholders and decision-makers. It addresses differences between labelling and rating systems and compares the importance of each system. This paper also highlights how priority levels used in sustainability assessment can vary between stakeholders on the assumption that the performance level for proposed indicators has equal value between stakeholders. This stage is carried out through the provision of feedback by each interested party on their perceptions of priority levels and impact of selected sustainability criteria for regional shopping centres. It is concluded that the priority level is largely dependent on who is carrying out the evaluation, and thus results in subjective assessments.