This paper aims to reconstruct the design process of Louis I. Kahn's Phillips Exeter Academy Library through a morphological analysis of the basic form applied by the architect. The analysis is structured as follows: 1. **Chronological Analysis of Design Sketches**: The basic form is identified through an analysis of chronologically ordered design sketches. 2. **Adaptability to Library's Architectural Program**: The basic form is examined for its adaptability to the library's architectural program. 3. **Discussion on the Basic Form**: The basic form is discussed for its role in controlling the relationship between program requirements and formal transformations in the design. The paper highlights the importance of understanding Kahn's design process by analyzing his sketches, which provide valuable insights into his thought processes and design methods. The Phillips Exeter Academy Library, one of Kahn's most significant works, is situated in New Hampshire and is part of the academy's campus, which is characterized by Neo-Jacobean architecture. The library's design process is traced through various stages, including initial sketches, structural considerations, and detailed studies of specific elements such as the entrance stairs and central hall. Key findings include: - The basic form of the library, characterized by a triple plan and a three-layer section, was established early in the design process and remained consistent throughout. - The central hall, a crucial element, was introduced by Kahn to create a unifying space that integrates and connects various functional areas. - The design process involved a balance between maintaining the basic form and adapting it to meet specific design conditions, such as cost constraints and program requirements. The paper concludes that Kahn's design philosophy was deeply rooted in his understanding of the relationship between form and function, and that the basic form played a central role in guiding the design and ensuring its success.This paper aims to reconstruct the design process of Louis I. Kahn's Phillips Exeter Academy Library through a morphological analysis of the basic form applied by the architect. The analysis is structured as follows: 1. **Chronological Analysis of Design Sketches**: The basic form is identified through an analysis of chronologically ordered design sketches. 2. **Adaptability to Library's Architectural Program**: The basic form is examined for its adaptability to the library's architectural program. 3. **Discussion on the Basic Form**: The basic form is discussed for its role in controlling the relationship between program requirements and formal transformations in the design. The paper highlights the importance of understanding Kahn's design process by analyzing his sketches, which provide valuable insights into his thought processes and design methods. The Phillips Exeter Academy Library, one of Kahn's most significant works, is situated in New Hampshire and is part of the academy's campus, which is characterized by Neo-Jacobean architecture. The library's design process is traced through various stages, including initial sketches, structural considerations, and detailed studies of specific elements such as the entrance stairs and central hall. Key findings include: - The basic form of the library, characterized by a triple plan and a three-layer section, was established early in the design process and remained consistent throughout. - The central hall, a crucial element, was introduced by Kahn to create a unifying space that integrates and connects various functional areas. - The design process involved a balance between maintaining the basic form and adapting it to meet specific design conditions, such as cost constraints and program requirements. The paper concludes that Kahn's design philosophy was deeply rooted in his understanding of the relationship between form and function, and that the basic form played a central role in guiding the design and ensuring its success.