diff --git a/blueprints/codes/eurocode/nen_en_1992_1_1_c2_2011/chapter_8_detailing_of_reinforcement_and_prestressing_tendons/formula_8_17.py b/blueprints/codes/eurocode/nen_en_1992_1_1_c2_2011/chapter_8_detailing_of_reinforcement_and_prestressing_tendons/formula_8_17.py
new file mode 100644
index 00000000..3fa63a64
--- /dev/null
+++ b/blueprints/codes/eurocode/nen_en_1992_1_1_c2_2011/chapter_8_detailing_of_reinforcement_and_prestressing_tendons/formula_8_17.py
@@ -0,0 +1,35 @@
+"""Formula 8.17 from NEN-EN 1992-1-1+C2:2011: Chapter 8: Detailing of reinforcement and prestressing tendons."""
+from blueprints.codes.eurocode.nen_en_1992_1_1_c2_2011 import NEN_EN_1992_1_1_C2_2011
+from blueprints.codes.formula import Formula
+from blueprints.type_alias import MM
+from blueprints.validations import raise_if_negative
+
+
+class Form8Dot17DesignValueTransmissionLength1(Formula):
+    """Class representing formula 8.17 for the calculation of design value 1 of the transmission length :math:`l_{pt1}`. The less favourable of
+    :math:`l_{pt1}` or :math:`l_{pt2}` has to be chosen depending on the design situation."""
+
+    label = "8.17"
+    source_document = NEN_EN_1992_1_1_C2_2011
+
+    def __init__(self, l_pt: MM) -> None:
+        """[:math:`l_{pt1}`] design value 1 of the transmission length [:math:`mm`].
+
+        NEN-EN 1992-1-1+C2:2011 art.8.10.2.2(3) - Formula (8.17)
+
+        Parameters
+        ----------
+        l_pt : MM
+            [:math:`l_{pt}`] Basic value of the transmission length [:math:`mm`].
+            Use your own implementation for this value or use :class:`Form8Dot16BasicTransmissionLength` class.
+        """
+        super().__init__()
+        self.l_pt = l_pt
+
+    @staticmethod
+    def _evaluate(
+        l_pt: MM,
+    ) -> MM:
+        """Evaluates the formula, for more information see the __init__ method."""
+        raise_if_negative(l_pt=l_pt)
+        return 0.8 * l_pt
diff --git a/tests/codes/eurocode/nen_en_1992_1_1_c2_2011/chapter_8_detailing_of_reinforcement_and_prestressing_tendons/test_formula_8_17.py b/tests/codes/eurocode/nen_en_1992_1_1_c2_2011/chapter_8_detailing_of_reinforcement_and_prestressing_tendons/test_formula_8_17.py
new file mode 100644
index 00000000..242b31b7
--- /dev/null
+++ b/tests/codes/eurocode/nen_en_1992_1_1_c2_2011/chapter_8_detailing_of_reinforcement_and_prestressing_tendons/test_formula_8_17.py
@@ -0,0 +1,50 @@
+"""Testing formula 8.17 of NEN-EN 1992-1-1+C2:2011."""
+import pytest
+
+from blueprints.codes.eurocode.nen_en_1992_1_1_c2_2011.chapter_8_detailing_of_reinforcement_and_prestressing_tendons.formula_8_16 import (
+    Form8Dot16BasicTransmissionLength,
+)
+from blueprints.codes.eurocode.nen_en_1992_1_1_c2_2011.chapter_8_detailing_of_reinforcement_and_prestressing_tendons.formula_8_17 import (
+    Form8Dot17DesignValueTransmissionLength1,
+)
+from blueprints.validations import NegativeValueError
+
+
+class TestForm8Dot17DesignValueTransmissionLength1:
+    """Validation for formula 8.17 from NEN-EN 1992-1-1+C2:2011."""
+
+    def test_evaluation(self) -> None:
+        """Test the evaluation of the result."""
+        # example values
+        l_pt = 120  # mm
+        form_8_17 = Form8Dot17DesignValueTransmissionLength1(l_pt=l_pt)
+        # manually calculated result
+        manually_calculated_result = 96  # mm
+
+        assert form_8_17 == pytest.approx(expected=manually_calculated_result, rel=1e-4)
+
+    def test_raise_error_if_negative_l_pt(self) -> None:
+        """Test that a NegativeValueError is raised when a negative value is passed for l_pt."""
+        l_pt = -1
+        with pytest.raises(NegativeValueError):
+            Form8Dot17DesignValueTransmissionLength1(l_pt=l_pt)
+
+    def test_integration_with_form_8_dot_16(self) -> None:
+        """Test integration between formula 8.16 and 8.17."""
+        alpha_1 = 1  # [-]
+        alpha_2 = 0.25  # [-]
+        diameter = 8  # mm
+        sigma_pm0 = 350  # MPa
+        f_bpt = 5  # MPa
+        l_pt = Form8Dot16BasicTransmissionLength(
+            alpha_1=alpha_1,
+            alpha_2=alpha_2,
+            diameter=diameter,
+            sigma_pm0=sigma_pm0,
+            f_bpt=f_bpt,
+        )
+
+        form_8_17 = Form8Dot17DesignValueTransmissionLength1(l_pt=l_pt)
+        manually_calculated_result = 112  # mm
+
+        assert form_8_17 == pytest.approx(expected=manually_calculated_result, rel=1e-4)