Web-PHIDIAS is a hypermedia-based, intelligent CAD system that delivers both CAD functionality and design information to anyone with Web access. This system is above all designed to facilitate collaborative architectural design. It provides both private (individual) and collaborative (group) drawing and text authoring spaces, with a variety of types of authoring and viewing privileges for groups. This enables a single designer to work in privacy on one piece of a design and later “publish” it to a supervisor or a group. It also enables a group to work in privacy and later publish its work to a different or larger group. This notion of “levels of privacy/publication” is a crucial but too- often missing component of collaborative design systems. With WebPHIDIAS, all drawings are stored in a central repository accessible from the group server. This means that they are accessible from anywhere in the world to any viewer who has the required viewing and/or authoring privileges. This enables designers to access and modify stored drawings while travelling or when out on the site, even if the site is in another country. It also enables them to create new drawings and store them in the central repository from anywhere in the world. Web-PHIDIAS consists of an interactive Web-based client that serves as an interface to the PHIDIAS hypermedia server. This client, which is implemented in Java, provides basic, 2D graphical editing functionality and as well as display of 3D views. It also provides access to multimedia information useful for whatever design task is at hand. This information includes text and graphical descriptions of design precedents as well as various issues in design of a particular type of building.