diff --git a/data/presets/power/generator/method/photovoltaic/building/roof.json b/data/presets/power/generator/method/photovoltaic/building/roof.json
index 9001aa75..679c9e76 100644
--- a/data/presets/power/generator/method/photovoltaic/building/roof.json
+++ b/data/presets/power/generator/method/photovoltaic/building/roof.json
@@ -22,7 +22,8 @@
         "generator:method": "photovoltaic",
         "generator:type": "solar_photovoltaic_panel",
         "generator:output:electricity": "*",
-        "building": "roof"
+        "building": "roof",
+        "layer": "1"
     },
     "reference": {
         "key": "generator:method",