Multi-Models address issues of nD modeling problems in construction information processes. They provide a temporary and loose coupling by aggregating instances of possibly orthogonal domain models and expressing explicit relations between their elements. To provide a base for prototypical and specific multi-model support as well as the development of generic multi-model based tools, the authors propose a data schema for a generic multi-model, consisting of an ID-based link model and two elementary model representations. Specifications of optional meta-data provide structural and semantic description of the data.