diff --git a/tests/unit/interpolator/test_interpolator_builder.py b/tests/unit/interpolator/test_interpolator_builder.py
new file mode 100644
index 00000000..ee12de1b
--- /dev/null
+++ b/tests/unit/interpolator/test_interpolator_builder.py
@@ -0,0 +1,78 @@
+import pytest
+import numpy as np
+from LoopStructural.datatypes import BoundingBox
+from LoopStructural.interpolators._interpolator_builder import InterpolatorBuilder
+from LoopStructural.interpolators import InterpolatorType
+
+
+@pytest.fixture
+def setup_builder():
+    bounding_box = BoundingBox(np.array([0, 0, 0]), np.array([1, 1, 1]))
+    interpolatortype = InterpolatorType.FINITE_DIFFERENCE
+    nelements = 1000
+    buffer = 0.2
+    builder = InterpolatorBuilder(
+        interpolatortype=interpolatortype,
+        bounding_box=bounding_box,
+        nelements=nelements,
+        buffer=buffer,
+    )
+    return builder
+
+
+def test_create_interpolator(setup_builder):
+    builder = setup_builder
+    builder.create_interpolator()
+    assert builder.interpolator is not None, "Interpolator should be created"
+
+
+def test_set_value_constraints(setup_builder):
+    builder = setup_builder
+    builder.create_interpolator()
+    value_constraints = np.array([[0.5, 0.5, 0.5, 1.0,1.]])
+    builder.set_value_constraints(value_constraints)
+    assert np.array_equal(
+        builder.interpolator.data['value'], value_constraints
+    ), "Value constraints should be set correctly"
+
+
+def test_set_gradient_constraints(setup_builder):
+    builder = setup_builder
+    builder.create_interpolator()
+    gradient_constraints = np.array([[0.5, 0.5, 0.5, 1.0, 0.0, 0.0,1.]])
+    builder.set_gradient_constraints(gradient_constraints)
+    assert np.array_equal(
+        builder.interpolator.data['gradient'], gradient_constraints
+    ), "Gradient constraints should be set correctly"
+
+
+def test_set_normal_constraints(setup_builder):
+    builder = setup_builder
+    builder.create_interpolator()
+    normal_constraints = np.array([[0.5, 0.5, 0.5, 1.0, 0.0, 0.0,1.]])
+    builder.set_normal_constraints(normal_constraints)
+    assert np.array_equal(
+        builder.interpolator.data['normal'], normal_constraints
+    ), "Normal constraints should be set correctly"
+
+
+def test_setup_interpolator(setup_builder):
+    builder = setup_builder
+    builder.create_interpolator()
+    value_constraints = np.array([[0.5, 0.5, 0.5, 1.0,1.]])
+    interpolator = builder.set_value_constraints(value_constraints).setup_interpolator()
+    assert interpolator is not None, "Interpolator should be set up"
+    assert np.array_equal(
+        interpolator.data['value'], value_constraints
+    ), "Value constraints should be set correctly after setup"
+
+
+def test_evaluate_scalar_value(setup_builder):
+    builder = setup_builder
+    builder.create_interpolator()
+    value_constraints = np.array([[0.5, 0.5, 0.5, 1.0]])
+    interpolator = builder.set_value_constraints(value_constraints).setup_interpolator()
+    locations = np.array([[0.5, 0.5, 0.5]])
+    values = interpolator.evaluate_value(locations)
+    assert values is not None, "Evaluation should return values"
+    assert values.shape == (1,), "Evaluation should return correct shape"