diff --git a/src/Speckle.Objects/Interfaces.cs b/src/Speckle.Objects/Interfaces.cs
index b2df1903..5d41a500 100644
--- a/src/Speckle.Objects/Interfaces.cs
+++ b/src/Speckle.Objects/Interfaces.cs
@@ -2,6 +2,7 @@ using Speckle.Objects.Geometry;
 using Speckle.Objects.Other;
 using Speckle.Objects.Primitive;
 using Speckle.Sdk.Models;
+using Speckle.Sdk.Models.Proxies;
 
 namespace Speckle.Objects;
 
@@ -110,15 +111,7 @@ public interface IDisplayValue<out T> : ISpeckleObject
 
 #region Data objects
 
-/// <summary>
-/// Specifies properties on objects to be used for data-based workflows
-/// </summary>
-public interface IProperties : ISpeckleObject
-{
-  Dictionary<string, object?> properties { get; }
-}
-
-public interface IDataObject : IProperties, IDisplayValue<IReadOnlyList<Base>>
+public interface IDataObject : IProperties, IDisplayValue<IReadOnlyList<Base>>, ISpeckleObject
 {
   /// <summary>
   /// The name of the object, primarily used to decorate the object for consumption in frontend and other apps
diff --git a/src/Speckle.Sdk/Models/Collections/RootCollection.cs b/src/Speckle.Sdk/Models/Collections/RootCollection.cs
index ace5979c..7082ba6b 100644
--- a/src/Speckle.Sdk/Models/Collections/RootCollection.cs
+++ b/src/Speckle.Sdk/Models/Collections/RootCollection.cs
@@ -1,3 +1,5 @@
+using Speckle.Sdk.Models.Proxies;
+
 namespace Speckle.Sdk.Models.Collections;
 
 /// <summary>
@@ -5,7 +7,7 @@ namespace Speckle.Sdk.Models.Collections;
 /// Extends Collection to include model-wide properties that apply to the entire model.
 /// </summary>
 [SpeckleType("Speckle.Core.Models.Collections.RootCollection")]
-public class RootCollection : Collection
+public class RootCollection : Collection, IProperties
 {
   public RootCollection() { }
 
@@ -15,8 +17,5 @@ public class RootCollection : Collection
   /// <summary>
   /// Model-wide properties that apply to the entire model.
   /// </summary>
-  /// <remarks>
-  /// These are intended for model-level metadata such as total area, project information, or analysis results.
-  /// </remarks>
-  public Dictionary<string, object?>? properties { get; set; }
+  public Dictionary<string, object?> properties { get; set; } = new();
 }
diff --git a/src/Speckle.Sdk/Models/Proxies/IProperties.cs b/src/Speckle.Sdk/Models/Proxies/IProperties.cs
new file mode 100644
index 00000000..1a1fc252
--- /dev/null
+++ b/src/Speckle.Sdk/Models/Proxies/IProperties.cs
@@ -0,0 +1,10 @@
+namespace Speckle.Sdk.Models.Proxies;
+
+/// <summary>
+/// Specifies properties on objects to be used for data-based workflows.
+/// Can be applied to both objects and collections.
+/// </summary>
+public interface IProperties
+{
+  Dictionary<string, object?> properties { get; }
+}