diff --git a/crates/fj-core/src/core.rs b/crates/fj-core/src/core.rs
index d4f273c18..e1e65fc7d 100644
--- a/crates/fj-core/src/core.rs
+++ b/crates/fj-core/src/core.rs
@@ -2,26 +2,46 @@
 //!
 //! See [`Core`].
 
-use crate::{layers::Layers, validation::ValidationConfig};
+use crate::{
+    algorithms::approx::Tolerance, layers::Layers, validation::ValidationConfig,
+};
 
 /// An instance of the Fornjot core
 ///
 /// This is the main entry point to `fj-core`'s API.
-#[derive(Default)]
 pub struct Core {
     /// The layers of data that make up the state of a core instance
     pub layers: Layers,
+
+    /// Default tolerance used for intermediate geometry representation
+    pub default_tolerance: Tolerance,
 }
 
 impl Core {
-    /// Construct an instance of `Instance`
+    /// Construct an instance of `Core`
     pub fn new() -> Self {
-        Self::default()
+        Self::from_layers(Layers::default())
     }
 
-    /// Construct an instance of `Instance`, using the provided configuration
+    /// Construct an instance of `Core`, using the provided configuration
     pub fn with_validation_config(config: ValidationConfig) -> Self {
         let layers = Layers::with_validation_config(config);
-        Self { layers }
+        Self::from_layers(layers)
+    }
+
+    fn from_layers(layers: Layers) -> Self {
+        let default_tolerance = Tolerance::from_scalar(0.001)
+            .expect("Tolerance provided is larger than zero");
+
+        Self {
+            layers,
+            default_tolerance,
+        }
+    }
+}
+
+impl Default for Core {
+    fn default() -> Self {
+        Self::new()
     }
 }