"This paper has focused on the Royal Philosophy of Sufficiency Economy and the ""Buddhist Principles"" applied to Real Estate Development. This paper shows the ideas leading to the sustainable real estate development for the better quality of living and the real happiness. The paper relates to conceptual models in Buddhist Principles and the Royal Philosophy of Sufficiency Economy linked to some theory in the process of Real Estate Project Development with a summary of ideas in increasing the happiness of life and the quality of living. Developing the concepts of ""Human Needs"" and the ""Buddhist Principles"" associated with the Royal Philosophy of Sufficiency Economy subject to the objective of ethics to meet the sustainable development and needs of happiness."