This technical report details the methodology that has been developed within ESPON M4D in order to combine and integrate in a single database data from heterogeneous sources, so that they can be queried to obtain valuable results. Data are integrated through a Reference Grid structure, at 1 km2 resolution or 100 m2 in the case of the urban data. This method has resulted in the production of different ESPON OLAP Cubes, at European, Urban and Neighbourhood levels. An ESPON OLAP webtool has been produced to facilitate querying the OLAP Cubes and get maps and charts in a swift way.