This document establishes a data framework that involves possible multi-source common data through standardized data integration and sharing mechanisms. It includes recommendations for: - precision, dimensions of the data, data collection, updates and storing mechanisms; - a data model for data integration, data standardization and data fusion approaches for heterogeneous smart city infrastructure data; - a data security level and sharable attributes for all involved data, principles on data sharing or exchange. This document focuses on the integration and application of heterogeneous data from urban infrastructure systems, such as water, transport, energy, drainage and waste, so as to support smart city planning (SCP). It contains case studies, in Annex A, of various smart city projects.