Hi Cliff, I take you point about time to create the ifc file. However we see a number of advantages of using ifc which have led us to make it the standard format for Tekla BIMsight. Ifc is an open standard controlled and regulated by the industry representative body Building Smart. This gives some stability and certainty over the format which all software vendors can work with. The dwg is a proprietary format, beholden to one company, subject to change from version to version as we regularly see. This means you always have to ask the question – which version of dwg? Dwg geometry data comes as faces so we don’t get all the solid data making it harder to manipulate and work with individual objects. To get this data requires support for so called Object Enablers. However, again, because of the closed proprietary nature of these we are not able to gain access. Many applications creating ifc allow you the user to control what attribute data is passed with the objects in the file. This offers great potential for BIM collaboration and communication. It’s this potential we are building Tekla BIMsight around. /Steve