Note: This is work in progress. The Sketch Chair system is a custom computational design environment built in Java that allows a user to design chairs using a sketch interface. The custom chair can be tailored to the user’s size –ergonomics-, and allows users to design different styles of chairs; stools, office chair etc. To make a chair the user draws profiles using a mouse or tablet pc, the system then extrudes this profile to produce a seating platform. Legs can then be added by the user by editing the generated profiles. The resulting chair is then tested using a physical simulation. A rag-doll representing the user is placed on the chair, to see how the user might sit on the newly designed chair, to test its ergonomics and to make sure the final design is stable enough to stand up. Laser cut profiles are automatically generated by the system and cut on a laser cutter. These profiles can be automatically sent to an external company for cutting and then shipped to the user. Or if the user has access to a laser cutter they are able to cut their own profiles. The chair is then able to be easily constructed by the user.