Before running Energy Analysis, it's worth making sure everything in the sketch is solid. You can use shortcut DW in FormIt to display watertight issues which indicate the shape is not solid or totally closed.
Any edges highlighted in red indicate that their parent geometry should be extruded (if it's flat) or closed (if it's 3D), before sending the model to Energy Analysis. FormIt's Energy Analysis uses Revit behind the scenes, and Revit likes solid/watertight models best.
If the geometry in question is 3D and exhibits watertight issues, you can try selecting one of the edges and using the Cover tool (shortcut CV) to automatically close the solid. Depending on the specific model, you might still have to manually close the 3D shape by drawing edges and faces to make it solid and watertight.
Josh Goldstein
Senior Product Manager