Now in addition to energy analysis of conceptual massing elements, in Revit 2014 you can perform energy analysis using detailed Revit models. The building elements simulation option creates an Energy Analytical Model directly from your Revit building elements and sends it to Autodesk Green Building Studio for simulation using DOE2.2. Once the analysis is complete, you can review and compare results as you continue to iterate the model and inform your design decisions. 

This innovative new algorithm automatically identifies and places analytical spaces and surfaces and creates gbXML.

 This new feature works both with and without the placement of Revit room / space objects - thereby facilitating whole building energy simulation with (as little as) "one click".  The tool also accounts for more complex model geometry like sloped walls, varying wall thickness and plenum spaces.  There is no need to prepare the model for analysis or rebuild a separate model.

  In Summary:  You can conduct more reliable, repeatable whole building energy analysis with less time and skill.