diff --git a/Environment_Engine/Modify/SetRegionGeometry.cs b/Environment_Engine/Modify/SetRegionGeometry.cs
new file mode 100644
index 000000000..dbb484a16
--- /dev/null
+++ b/Environment_Engine/Modify/SetRegionGeometry.cs
@@ -0,0 +1,57 @@
+/*
+ * This file is part of the Buildings and Habitats object Model (BHoM)
+ * Copyright (c) 2015 - 2022, the respective contributors. All rights reserved.
+ *
+ * Each contributor holds copyright over their respective contributions.
+ * The project versioning (Git) records all such contribution source information.
+ *                                           
+ *                                                                              
+ * The BHoM is free software: you can redistribute it and/or modify         
+ * it under the terms of the GNU Lesser General Public License as published by  
+ * the Free Software Foundation, either version 3.0 of the License, or          
+ * (at your option) any later version.                                          
+ *                                                                              
+ * The BHoM is distributed in the hope that it will be useful,              
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of               
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 
+ * GNU Lesser General Public License for more details.                          
+ *                                                                            
+ * You should have received a copy of the GNU Lesser General Public License     
+ * along with this code. If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.      
+ */
+
+using System.ComponentModel;
+using BH.oM.Base.Attributes;
+using System.Collections.Generic;
+using System.Linq;
+using System;
+
+using BH.oM.Environment.Elements;
+
+using BH.Engine.Geometry;
+using BH.oM.Geometry;
+using BH.Engine.Base;
+using BH.oM.Analytical.Elements;
+
+namespace BH.Engine.Environment
+{
+    public static partial class Modify
+    {
+        [Description("Match closed Polylines to Regions (e.g. Rooms/Spaces) and update geometry. Where a Region Location point exists within a closed Polyline, the Polyline will be set as the Region Perimeter value.")]
+        [Input("polyline", "A closed polyline representing the new Region Perimeter to be assigned.")]
+        [Input("region", "Original Regions where Perimeter property is to be updated.")]
+        [Output("region", "Regions with updated Perimeter geometry.")]
+        public static List<IRegion> SetRegionGeometry(this List<Polyline> polyline, List<IRegion> region)
+        {
+            List<IRegion> returnRegions = new List<IRegion>();
+            foreach (IRegion newRegion in region)
+            {
+                Point pointinregion = newRegion.Perimeter.PointInRegion();
+                Polyline newGeometry = polyline.Where(x => x.IIsContaining(new List<Point>() { pointinregion })).FirstOrDefault();
+                newRegion.Perimeter = newGeometry;
+                returnRegions.Add(newRegion);
+            }
+            return returnRegions;
+        }  
+    }
+}