public XElement GetAnalyticalShadingSurfaces()
{
// create a node that places all shading surfaces
XElement shadingSurfacesNode = new XElement("ShadingSurfaces1");
shadingSurfacesNode.Add(new XAttribute("Name", "ShadingSurfaces"));
// get shadingSurfaces from Model
IList<EnergyAnalysisSurface> shadingSurfaces = m_energyAnalysisDetailModel.GetAnalyticalShadingSurfaces();
SurfacesToXElement(shadingSurfacesNode, shadingSurfaces);
return shadingSurfacesNode;
}