diff --git a/Geometry_Engine/Create/NurbSurface.cs b/Geometry_Engine/Create/NurbsSurface.cs
similarity index 100%
rename from Geometry_Engine/Create/NurbSurface.cs
rename to Geometry_Engine/Create/NurbsSurface.cs
diff --git a/Geometry_Engine/Geometry_Engine.csproj b/Geometry_Engine/Geometry_Engine.csproj
index 0385f47b4..56585b7a3 100644
--- a/Geometry_Engine/Geometry_Engine.csproj
+++ b/Geometry_Engine/Geometry_Engine.csproj
@@ -149,6 +149,7 @@
     <Compile Include="Query\IsCoplanar.cs" />
     <Compile Include="Query\IsLinear.cs" />
     <Compile Include="Query\IsOnCurve.cs" />
+    <Compile Include="Query\IsPeriodic.cs" />
     <Compile Include="Query\IsPlanar.cs" />
     <Compile Include="Query\IsPolylinear.cs" />
     <Compile Include="Query\IsQuad.cs" />
diff --git a/Geometry_Engine/Query/Degree.cs b/Geometry_Engine/Query/Degree.cs
index 513b2d39f..62e4b8f8d 100644
--- a/Geometry_Engine/Query/Degree.cs
+++ b/Geometry_Engine/Query/Degree.cs
@@ -37,18 +37,5 @@ public static int Degree(this NurbsCurve curve)
         }
 
         /***************************************************/
-
-        public static List<int> Degrees(this NurbsSurface surf)
-        {
-            int uDegree = 1;
-            int vDegree = 1;
-            while (surf.UKnots[uDegree - 1] == surf.UKnots[uDegree])
-                uDegree++;
-            while (surf.VKnots[vDegree - 1] == surf.VKnots[vDegree])
-                vDegree++;
-            return new List<int>() { uDegree, vDegree };
-        }
-
-        /***************************************************/
     }
 }
diff --git a/Geometry_Engine/Query/IsClosed.cs b/Geometry_Engine/Query/IsClosed.cs
index 734cff141..243751069 100644
--- a/Geometry_Engine/Query/IsClosed.cs
+++ b/Geometry_Engine/Query/IsClosed.cs
@@ -110,6 +110,19 @@ public static bool IIsClosed(this ICurve curve, double tolerance = Tolerance.Dis
             return IsClosed(curve as dynamic, tolerance);
         }
 
+
+        /***************************************************/
+        /**** Public Methods - Nurbs Surfaces           ****/
+        /***************************************************/
+
+        public static bool IsClosed(this NurbsSurface surface, double tolerance = Tolerance.Distance)
+        {
+            double sqTolerance = tolerance * tolerance;
+            List<int> uvCount = surface.UVCount();
+            return Enumerable.Range(0, uvCount[1]).All(i => surface.ControlPoints[i].SquareDistance(surface.ControlPoints[surface.ControlPoints.Count - uvCount[1] + i]) <= sqTolerance)
+                || Enumerable.Range(0, uvCount[0]).All(i => surface.ControlPoints[i * uvCount[1]].SquareDistance(surface.ControlPoints[(i + 1) * uvCount[1] - 1]) <= sqTolerance);
+        }
+
         /***************************************************/
     }
 }
diff --git a/Geometry_Engine/Query/IsPeriodic.cs b/Geometry_Engine/Query/IsPeriodic.cs
new file mode 100644
index 000000000..43f543549
--- /dev/null
+++ b/Geometry_Engine/Query/IsPeriodic.cs
@@ -0,0 +1,49 @@
+/*
+ * This file is part of the Buildings and Habitats object Model (BHoM)
+ * Copyright (c) 2015 - 2018, 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.Collections.Generic;
+using BH.oM.Geometry;
+
+namespace BH.Engine.Geometry
+{
+    public static partial class Query
+    {
+        /***************************************************/
+        /**** Public Methods                            ****/
+        /***************************************************/
+
+        public static bool IsPeriodic(this NurbsSurface surface)
+        {
+            int uMultiplicity = 1;
+            int vMultiplicity = 1;
+
+            while (surface.UKnots[uMultiplicity - 1] == surface.UKnots[uMultiplicity])
+                uMultiplicity++;
+            while (surface.VKnots[vMultiplicity - 1] == surface.VKnots[vMultiplicity])
+                vMultiplicity++;
+
+            return (uMultiplicity != surface.UDegree || vMultiplicity != surface.VDegree);
+        }
+
+        /***************************************************/
+    }
+}
diff --git a/Geometry_Engine/Query/UVCount.cs b/Geometry_Engine/Query/UVCount.cs
index 40b0ad698..0eb99e5c4 100644
--- a/Geometry_Engine/Query/UVCount.cs
+++ b/Geometry_Engine/Query/UVCount.cs
@@ -33,8 +33,7 @@ public static partial class Query
 
         public static List<int> UVCount(this NurbsSurface surf)
         {
-            List<int> degrees = surf.Degrees();
-            return new List<int> { surf.UKnots.Count - degrees[0] + 1, surf.VKnots.Count - degrees[1] + 1 };
+            return new List<int> { surf.UKnots.Count - surf.UDegree + 1, surf.VKnots.Count - surf.VDegree + 1 };
         }
 
         /***************************************************/