diff --git a/exports/formats/idf.py b/exports/formats/idf.py
index 92f6b576..c635cb86 100644
--- a/exports/formats/idf.py
+++ b/exports/formats/idf.py
@@ -44,6 +44,8 @@ class Idf:
   _LOCATION = 'SITE:LOCATION'
   _WINDOW_MATERIAL_SIMPLE = 'WINDOWMATERIAL:SIMPLEGLAZINGSYSTEM'
   _WINDOW = 'WINDOW'
+  _ROOFIRRIGATION = 'ROOFIRRIGATION'
+  _MATERIAL_ROOFVEGETATION = 'MATERIAL:ROOFVEGETATION'
 
   idf_surfaces = {
     # todo: make an enum for all the surface types
@@ -433,3 +435,29 @@ class Idf:
              material['Solar_Heat_Gain_Coefficient'] == opening.g_value:
           return True
     return False
+
+  def _add_vegetation_material(self, vegetation_layer):
+    for vegetation_material in self._idf.idfobjects[self._MATERIAL_ROOFVEGETATION]:
+      if vegetation_material.Name == vegetation_layer.name:
+        return
+      self._idf.newidfobject(self._MATERIAL_ROOFVEGETATION,
+                             Name='',
+                             Height_of_Plants='',
+                             Leaf_Area_Index='',
+                             Leaf_Reflectivity='',
+                             Leaf_Emissivity='',
+                             Minimum_Stomatal_Resistance='',
+                             Soil_Layer_Name='',
+                             Roughness=self._ROUGHNESS,
+                             Thickness='',
+                             Conductivity_of_Dry_Soil='',
+                             Density_of_Dry_Soil='',
+                             Specific_Heat_of_Dry_Soil='',
+                             Thermal_Absorptance='',
+                             Solar_Absorptance='',
+                             Visible_Absorptance='',
+                             Saturation_Volumetric_Moisture_Content_of_the_Soil_Layer='',
+                             Residual_Volumetric_Moisture_Content_of_the_Soil_Layer='',
+                             Initial_Volumetric_Moisture_Content_of_the_Soil_Layer='',
+                             Moisture_Diffusion_Calculation_Method=''
+                             )