diff --git a/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.cpp b/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.cpp
index a5e6fdea62d..ee63b8c41ae 100644
--- a/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.cpp
+++ b/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.cpp
@@ -11,6 +11,10 @@
 
 #include "BHECommonCoaxial.h"
 
+#include "Physics.h"
+#include "ThermalResistancesCoaxial.h"
+#include "ThermoMechanicalFlowProperties.h"
+
 namespace ProcessLib
 {
 namespace HeatTransportBHE
@@ -111,6 +115,27 @@ BHECommonCoaxial::calcThermalResistances(double const Nu_inner_pipe,
 
     return getThermalResistances(R_gs, R_ff, R_fg);
 }
+
+void BHECommonCoaxial::updateHeatTransferCoefficients(double const flow_rate)
+{
+    auto const tm_flow_properties_annulus =
+        calculateThermoMechanicalFlowPropertiesAnnulus(_pipes.inner_pipe,
+                                                       _pipes.outer_pipe,
+                                                       borehole_geometry.length,
+                                                       refrigerant,
+                                                       flow_rate);
+
+    _flow_velocity_annulus = tm_flow_properties_annulus.velocity;
+
+    auto const tm_flow_properties = calculateThermoMechanicalFlowPropertiesPipe(
+        _pipes.inner_pipe, borehole_geometry.length, refrigerant, flow_rate);
+
+    _flow_velocity_inner = tm_flow_properties.velocity;
+
+    _thermal_resistances =
+        calcThermalResistances(tm_flow_properties.nusselt_number,
+                               tm_flow_properties_annulus.nusselt_number);
+}
 }  // namespace BHE
 }  // namespace HeatTransportBHE
 }  // namespace ProcessLib
diff --git a/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.h b/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.h
index 9420c88caa7..45d8b4fc02a 100644
--- a/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.h
+++ b/ProcessLib/HeatTransportBHE/BHE/BHECommonCoaxial.h
@@ -12,10 +12,7 @@
 #include <Eigen/Eigen>
 #include "BHECommon.h"
 #include "FlowAndTemperatureControl.h"
-#include "Physics.h"
 #include "PipeConfigurationCoaxial.h"
-#include "ThermalResistancesCoaxial.h"
-#include "ThermoMechanicalFlowProperties.h"
 
 namespace ProcessLib
 {
@@ -68,31 +65,7 @@ class BHECommonCoaxial : public BHECommon
         cross_section_area_grout;
 
 protected:
-    void updateHeatTransferCoefficients(double const flow_rate)
-    {
-        auto const tm_flow_properties_annulus =
-            calculateThermoMechanicalFlowPropertiesAnnulus(
-                _pipes.inner_pipe,
-                _pipes.outer_pipe,
-                borehole_geometry.length,
-                refrigerant,
-                flow_rate);
-
-        _flow_velocity_annulus = tm_flow_properties_annulus.velocity;
-
-        auto const tm_flow_properties =
-            calculateThermoMechanicalFlowPropertiesPipe(
-                _pipes.inner_pipe,
-                borehole_geometry.length,
-                refrigerant,
-                flow_rate);
-
-        _flow_velocity_inner = tm_flow_properties.velocity;
-
-        _thermal_resistances =
-            calcThermalResistances(tm_flow_properties.nusselt_number,
-                                   tm_flow_properties_annulus.nusselt_number);
-    }
+    void updateHeatTransferCoefficients(double const flow_rate);
 
     PipeConfigurationCoaxial const _pipes;
 
diff --git a/ProcessLib/HeatTransportBHE/BHE/BHE_1U.cpp b/ProcessLib/HeatTransportBHE/BHE/BHE_1U.cpp
index 6eea5f4ff6a..d7ce1ffc0f5 100644
--- a/ProcessLib/HeatTransportBHE/BHE/BHE_1U.cpp
+++ b/ProcessLib/HeatTransportBHE/BHE/BHE_1U.cpp
@@ -182,7 +182,7 @@ void BHE_1U::updateHeatTransferCoefficients(double const flow_rate)
 std::array<double, BHE_1U::number_of_unknowns> BHE_1U::calcThermalResistances(
     double const Nu)
 {
-    static constexpr double pi = boost::math::constants::pi<double>();
+    constexpr double pi = boost::math::constants::pi<double>();
 
     double const& lambda_r = refrigerant.thermal_conductivity;
     double const& lambda_g = grout.lambda_g;
diff --git a/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.cpp b/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.cpp
index 053605a4238..e0791f27c8e 100644
--- a/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.cpp
+++ b/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.cpp
@@ -11,6 +11,9 @@
 
 #include "CreateBHECoaxial.h"
 #include "BaseLib/ConfigTree.h"
+
+#include "BHE_CXA.h"
+#include "BHE_CXC.h"
 #include "CreateFlowAndTemperatureControl.h"
 namespace ProcessLib
 {
diff --git a/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.h b/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.h
index 306be4b36f7..ed7a981498b 100644
--- a/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.h
+++ b/ProcessLib/HeatTransportBHE/BHE/CreateBHECoaxial.h
@@ -10,8 +10,6 @@
 #pragma once
 
 #include "BHECommonCoaxial.h"
-#include "BHE_CXA.h"
-#include "BHE_CXC.h"
 
 namespace BaseLib
 {
diff --git a/ProcessLib/HeatTransportBHE/BHE/GroutParameters.h b/ProcessLib/HeatTransportBHE/BHE/GroutParameters.h
index beb7a1aaa30..90c5bf964e0 100644
--- a/ProcessLib/HeatTransportBHE/BHE/GroutParameters.h
+++ b/ProcessLib/HeatTransportBHE/BHE/GroutParameters.h
@@ -11,8 +11,6 @@
 
 #pragma once
 
-#include <boost/math/constants/constants.hpp>
-
 namespace BaseLib
 {
 class ConfigTree;
diff --git a/ProcessLib/HeatTransportBHE/BHE/Physics.h b/ProcessLib/HeatTransportBHE/BHE/Physics.h
index 12c929ffa96..d705c3d0458 100644
--- a/ProcessLib/HeatTransportBHE/BHE/Physics.h
+++ b/ProcessLib/HeatTransportBHE/BHE/Physics.h
@@ -11,8 +11,6 @@
 
 #pragma once
 
-#include "Pipe.h"
-
 namespace ProcessLib
 {
 namespace HeatTransportBHE
diff --git a/ProcessLib/HeatTransportBHE/BHE/PipeConfiguration1U.h b/ProcessLib/HeatTransportBHE/BHE/PipeConfiguration1U.h
index df49e4db268..d3d99ec9188 100644
--- a/ProcessLib/HeatTransportBHE/BHE/PipeConfiguration1U.h
+++ b/ProcessLib/HeatTransportBHE/BHE/PipeConfiguration1U.h
@@ -11,9 +11,6 @@
 
 #pragma once
 
-#include <boost/math/constants/constants.hpp>
-
-#include "BaseLib/ConfigTree.h"
 #include "Pipe.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/HeatTransportBHE/BHE/PipeConfigurationCoaxial.h b/ProcessLib/HeatTransportBHE/BHE/PipeConfigurationCoaxial.h
index 91aca4a7a76..122cd836fbd 100644
--- a/ProcessLib/HeatTransportBHE/BHE/PipeConfigurationCoaxial.h
+++ b/ProcessLib/HeatTransportBHE/BHE/PipeConfigurationCoaxial.h
@@ -11,9 +11,6 @@
 
 #pragma once
 
-#include <boost/math/constants/constants.hpp>
-
-#include "BaseLib/ConfigTree.h"
 #include "Pipe.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/HeatTransportBHE/BHE/RefrigerantProperties.h b/ProcessLib/HeatTransportBHE/BHE/RefrigerantProperties.h
index 0cb06ba1fc1..171a0d7bdd4 100644
--- a/ProcessLib/HeatTransportBHE/BHE/RefrigerantProperties.h
+++ b/ProcessLib/HeatTransportBHE/BHE/RefrigerantProperties.h
@@ -11,8 +11,6 @@
 
 #pragma once
 
-#include <boost/math/constants/constants.hpp>
-
 namespace BaseLib
 {
 class ConfigTree;
diff --git a/ProcessLib/HeatTransportBHE/BHE/ThermalResistancesCoaxial.h b/ProcessLib/HeatTransportBHE/BHE/ThermalResistancesCoaxial.h
index 336a57842da..99001843ed1 100644
--- a/ProcessLib/HeatTransportBHE/BHE/ThermalResistancesCoaxial.h
+++ b/ProcessLib/HeatTransportBHE/BHE/ThermalResistancesCoaxial.h
@@ -12,7 +12,6 @@
 #pragma once
 
 #include "GroutParameters.h"
-#include "Physics.h"
 #include "Pipe.h"
 #include "RefrigerantProperties.h"
 
@@ -24,9 +23,9 @@ namespace BHE
 {
 struct AdvectiveThermalResistanceCoaxial
 {
-    double inner_pipe_coaxial;
-    double a_annulus;
-    double b_annulus;
+    double const inner_pipe_coaxial;
+    double const a_annulus;
+    double const b_annulus;
 };
 
 struct PipeWallThermalResistanceCoaxial
@@ -50,7 +49,7 @@ inline AdvectiveThermalResistanceCoaxial calculateAdvectiveThermalResistance(
         coaxialPipesAnnulusDiameter(inner_pipe, outer_pipe);
 
     auto advective_thermal_resistance = [&](double Nu, double diameter_ratio) {
-        static constexpr double pi = boost::math::constants::pi<double>();
+        constexpr double pi = boost::math::constants::pi<double>();
         return 1.0 / (Nu * fluid.thermal_conductivity * pi) * diameter_ratio;
     };
     return {advective_thermal_resistance(Nu_inner_pipe, 1.),
@@ -72,7 +71,7 @@ calculateGroutAndGroutSoilExchangeThermalResistance(
     Pipe const& outer_pipe, GroutParameters const& grout_parameters,
     double const borehole_diameter)
 {
-    static constexpr double pi = boost::math::constants::pi<double>();
+    constexpr double pi = boost::math::constants::pi<double>();
 
     double const outer_pipe_outside_diameter = outer_pipe.outsideDiameter();
     double const chi =