1. A method for dynamically loading portions of a computer-aided design (CAD) model on demand, comprising: loading, by a CAD application executed by a processor of a computing device, a first portion of a CAD model, the first portion comprising (i) a modular structure of the CAD model and (ii) graphics and geometry data of a first element of the modular structure; selecting, by a user of the CAD application, a second element of the modular structure; and loading, by the CAD application and responsive to the selection, a second portion of the CAD model, the second portion comprising (i) a modular structure of the selected second element and (ii) graphics and geometry data of the selected second element.