In architecture and interior design, a parti (short for "parti pris," French for "taken part") is a basic diagram or concept sketch that captures the overall design idea and organization of a building or space. A parti is a simple, abstract representation of the key elements, relationships, and hierarchies that inform the design, and serves as a guiding principle throughout the design process.

A parti typically consists of simple geometric shapes, lines, and annotations that convey the essential spatial and functional relationships of the building, such as the location of entrances, the organization of public and private spaces, the circulation patterns, and the orientation to the site and context.

The purpose of a parti is to establish a clear and compelling design concept that can be easily communicated and developed throughout the design process. It helps to ensure that the design remains focused, coherent, and consistent, even as it evolves and becomes more detailed and complex.

There are several key characteristics of a successful parti:

1. Clarity: A parti should be clear, concise, and easily understandable, using simple and abstract forms that convey the essential ideas and relationships of the design.

2. Hierarchy: A parti should establish a clear hierarchy of spaces, elements, and functions, using size, position, and orientation to indicate their relative importance and relationships.

3. Flexibility: A parti should be flexible and adaptable, allowing for variations and refinements as the design progresses, while still maintaining the essential concept and organization.

4. Contextualism: A parti should respond to the specific context and site conditions of the project, such as the climate, topography, views, and surrounding buildings, and reflect the unique character and identity of the place.

5. Meaning: A parti should convey a sense of meaning and purpose, expressing the values, aspirations, and cultural significance of the project, and creating a strong emotional and symbolic resonance with the users and stakeholders.

Partis can take many different forms and styles, depending on the type and scale of the project, as well as the personal preferences and design philosophies of the architect or designer. Some common types of partis include:

• Linear: A parti that organizes spaces along a straight or curved line, often used in narrow or elongated sites, or to create a clear sequence of experiences.

• Radial: A parti that organizes spaces around a central point or axis, often used to create a strong sense of focus, hierarchy, and symmetry.

• Clustered: A parti that groups spaces into distinct clusters or zones, often used to create a sense of intimacy, diversity, and adaptability.

• Grid: A parti that organizes spaces within a regular, orthogonal grid, often used to create a sense of order, modularity, and efficiency.

• Freeform: A parti that uses organic, fluid, or asymmetrical forms, often used to create a sense of dynamism, creativity, and responsiveness to the site and context.

The development of a parti is a critical step in the architectural design process, as it sets the foundation for all subsequent decisions and explorations. By carefully crafting a clear, compelling, and meaningful parti, architects and designers can create buildings and spaces that are both functional and expressive, and that resonate with the needs, aspirations, and identities of the people who use them.