diff --git a/dune/iga/io/ibra/ibrareader.hh b/dune/iga/io/ibra/ibrareader.hh
index 4046e956..d3c6add5 100644
--- a/dune/iga/io/ibra/ibrareader.hh
+++ b/dune/iga/io/ibra/ibrareader.hh
@@ -28,7 +28,7 @@ namespace Dune::IGA {
     using PatchData           = Dune::IGA::NURBSPatchData<gridDim, worldDim>;
     using ControlPointNetType = Dune::IGA::MultiDimensionNet<gridDim, ControlPoint>;
 
-    static std::shared_ptr<Grid> read(const std::string& fileName, const bool trim = true,
+    static std::unique_ptr<Grid> read(const std::string& fileName, const bool trim = true,
                                       std::array<int, 2> elevateDegree  = {0, 0},
                                       std::array<int, 2> preKnotRefine  = {0, 0},
                                       std::array<int, 2> postKnotRefine = {0, 0}) {
@@ -40,7 +40,7 @@ namespace Dune::IGA {
     template <typename InputStringType>
     requires(not std::convertible_to<
                  std::string, InputStringType> and not std::convertible_to<InputStringType, const char*>) static std::
-        shared_ptr<Grid> read(InputStringType& ibraInputFile, const bool trim = true,
+        unique_ptr<Grid> read(InputStringType& ibraInputFile, const bool trim = true,
                               std::array<int, 2> elevateDegree = {0, 0}, std::array<int, 2> preKnotRefine = {0, 0},
                               std::array<int, 2> postKnotRefine = {0, 0}) {
       using json = nlohmann::json;
@@ -129,9 +129,9 @@ namespace Dune::IGA {
       auto trimData = constructGlobalBoundaries(brep);
 
       if (trim)
-        return std::make_shared<Grid>(_patchData, trimData);
+        return std::make_unique<Grid>(_patchData, trimData);
       else
-        return std::make_shared<Grid>(_patchData);
+        return std::make_unique<Grid>(_patchData);
     }
 
    private:
diff --git a/dune/iga/test/trimmedGridTests.cc b/dune/iga/test/trimmedGridTests.cc
index ffd75b04..9b59ca21 100644
--- a/dune/iga/test/trimmedGridTests.cc
+++ b/dune/iga/test/trimmedGridTests.cc
@@ -178,7 +178,7 @@ auto testPatchGeometrySurface() {
 auto testIbraReader() {
   TestSuite t;
 
-  std::shared_ptr<NURBSGrid<2, 2>> grid = IbraReader<2, 2>::read("auxiliaryFiles/element.ibra");
+  auto grid = IbraReader<2, 2>::read("auxiliaryFiles/element.ibra");
 
   // Check n_ele = 1, n_vert = 4
   t.check(grid->size(0) == 1);
@@ -202,7 +202,7 @@ auto testIbraReader() {
     t.check(ele.geometry().center() == expectedElementCenters[indexSet.index(ele)]);
 
   // Test Instantiation
-  std::shared_ptr<NURBSGrid<2, 3>> grid3D = IbraReader<2, 3>::read("auxiliaryFiles/shell.ibra");
+  auto grid3D = IbraReader<2, 3>::read("auxiliaryFiles/shell.ibra");
   grid3D->globalRefine(2);
 
   return t;
@@ -217,7 +217,7 @@ auto testDataCollectorAndVtkWriter() {
   std::vector<std::string> geometries{"element_trim_xb", "surface-hole"};
 
   for (auto& fileName : geometries) {
-    std::shared_ptr<NURBSGrid<2, 2>> grid = IbraReader<2, 2>::read("auxiliaryFiles/" + fileName + ".ibra");
+    auto grid = IbraReader<2, 2>::read("auxiliaryFiles/" + fileName + ".ibra");
 
     for (auto r : std::views::iota(0, 4)) {
       if (r > 0) grid->globalRefine(1);
@@ -334,7 +334,7 @@ auto testMapsInTrimmedPatch() {
   }
 
   // Load next example Grid
-  std::shared_ptr<NURBSGrid<2, 2>> grid2 = IbraReader<2, 2>::read("auxiliaryFiles/element_trim_xb.ibra");
+  auto grid2 = IbraReader<2, 2>::read("auxiliaryFiles/element_trim_xb.ibra");
   grid2->globalRefine(1);
   auto& patch_2_1 = grid2->getPatch();
 
@@ -396,7 +396,7 @@ auto testIntegrationPoints() {
   /// 1. test case A = 10 * 10, r = 3
   auto targetArea = 10 * 10 - (std::numbers::pi * std::pow(3, 2));
 
-  std::shared_ptr<NURBSGrid<2, 2>> grid = IbraReader<2, 2>::read("auxiliaryFiles/surface-hole.ibra");
+  auto grid = IbraReader<2, 2>::read("auxiliaryFiles/surface-hole.ibra");
   grid->globalRefine(1);
 
   double area = calculateArea(grid->leafGridView(), std::nullopt);
@@ -422,7 +422,7 @@ auto testIntegrationPoints() {
   targetArea = 20 * 2 - (std::numbers::pi * std::pow(0.3, 2));
 
   std::cout << "Grid 2 \n";
-  std::shared_ptr<NURBSGrid<2, 2>> grid2 = IbraReader<2, 2>::read("auxiliaryFiles/infty_pwh.ibra");
+  auto grid2 = IbraReader<2, 2>::read("auxiliaryFiles/infty_pwh.ibra");
   grid2->globalRefine(1);
 
   area = calculateArea(grid2->leafGridView());
@@ -454,7 +454,7 @@ auto testNurbsBasis() {
     }
   };
 
-  std::shared_ptr<NURBSGrid<2, 2>> grid = IbraReader<2, 2>::read("auxiliaryFiles/element_trim_xb.ibra");
+  auto grid = IbraReader<2, 2>::read("auxiliaryFiles/element_trim_xb.ibra");
   runBasisChecks(grid, 4);
 
   grid = IbraReader<2, 2>::read("auxiliaryFiles/element_trim_xb.ibra", true, {1, 1});