Computer Aided Design means not only aiding the preparation of technical documentation for building purposes or for the presentation of architectural design. The application of computer technology has a deeper meaning, when used for the creative modelling of designed objects and spaces. This article will help to define and describe Computer Parametric Modelling as an example of creative computer use. All conclusions presented in this article are based on a four year long working experience using the computer program MODEL, utilising parametric modelling in architectural and town-planning design by the author of this article. This program was created by the author and he is the only user at the present time, but it is hoped that it will be available for general use in the future.