In recent decades, coastal tourism has grown significantly bringing enormous economic benefits to host communities, and causing many environmental and social impacts to the coastal environment. Beach resort development faces problems due to an inability on the part of stakeholders to make sound decisions about sustainable design due, in part, to the complexity of the sustainability issues and the lack of a comprehensive decision-making tool to assist them. In Egypt, design and planning regulations have not changed for decades, resulting in non-sustainable beach resort development. This study provides a “decision framework,” a conceptual “Sustainable Design Model”, which shifts the focus of stakeholders from the application of traditional physical carrying capacity procedures to a comprehensive approach linking sustainability indicators and carrying capacities. This approach includes an array of acceptable capacities based on the ecological, social, psychological, physical, economic, and managerial capacity thresholds of a site. This framework assists stakeholders in making rational decisions about what is to be built, where it is located, and how to build it. To test the model, a survey was conducted at 10 beach resort destinations (5 American, 5 Egyptian) to measure the difference in perceptions between stakeholders concerning sustainability indicators and carrying capacities. The instrument was determined valid and reliable using a test/retest procedure. A total of 276 responses were obtained for data analysis. Statistical analyses included frequency distribution, t-tests, analysis of variance (ANOVA), factor analysis, and a stepwise multiple regression analysis. Sample demographic information was also collected. Results revealed a strong link between sustainability indicators and carrying capacity thresholds. While both Egyptian and American respondents recognized the importance of sensitive environmental developments, there were significant differences due to differences in culture, environment, regulations, and priorities. The American sample placed greater importance on the ecological indicators, while the Egyptian sample placed greater importance on the social, psychological, and managerial indicators. The American sample conveyed a positive attitude toward government regulations, design, and management efforts to incorporate sustainability principles into the built environment, while the Egyptian respondents conveyed a more negative attitude. As a result of this study, future Egyptian policy may be better informed of the gap between the theoretical concepts of sustainability and real world coastal development implementation.