A feature-based modelling system (FBMS) offers features of engineering significance such as slot, pocket and rib as model-building primitives, unlike the solid primitives offered by conventional constructive solid geometry (CSG) modelling systems. The usual practice is to build FBMS over a conventional CSG modelling system. In such a system the evaluated boundary representation of the part is generated by converting features into solid primitives and corresponding Boolean operations. We propose a direct method of gluing the feature. The feature representation generated from the input specification is merged with the representation of the base-solid based on the gluing rules implicit in the feature type definition. Generic features are identified by rational classification of the features of engineering significance. Feature definitions are structured such that the generic content is separated from the non-generic content. Gluing operators are developed for all generic types. The major conclusion drawn from this work is that the percolation of the knowledge that can be associated with features at the model-building level enables implementation of systems that display intelligence.