diff --git a/.github/workflows/buildCSharp.yml b/.github/workflows/buildCSharp.yml
index 9fdcc379652..cf4b0f2c11a 100644
--- a/.github/workflows/buildCSharp.yml
+++ b/.github/workflows/buildCSharp.yml
@@ -35,25 +35,21 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-      # If you need to rebuild for a specific branch **after** you fixed the workflow...
-      with:
-        ref: v3.8.0
+      # If you need to rebuild for a specific branch or tag **after** you fixed the workflow and you have no other changes or only a few you can download from github
+      # with:
+      #   ref: v3.8.0
+
+#    - name: download patched CMakeLists.txt
+#      shell: bash
+#      run: |
+#        rm CMakeLists.txt
+#        aria2c https://raw.githubusercontent.com/NREL/OpenStudio/CSharp/CMakeLists.txt
 
-    - name: download patched CMakeLists.txt
+    - name: Soft reset to v3.8.0
       shell: bash
       run: |
-        rm CMakeLists.txt
-        aria2c https://raw.githubusercontent.com/NREL/OpenStudio/CSharp/CMakeLists.txt
-        rm conan.lock
-        aria2c https://raw.githubusercontent.com/NREL/OpenStudio/CSharp/conan.lock
-        rm conanfile.py
-        aria2c https://raw.githubusercontent.com/NREL/OpenStudio/CSharp/conanfile.py
-        cd src/measure/
-        rm Measure.i
-        aria2c https://raw.githubusercontent.com/NREL/OpenStudio/CSharp/src/measure/Measure.i
-        cd ../utilities/core/
-        rm jsoncpp.i
-        aria2c https://raw.githubusercontent.com/NREL/OpenStudio/CSharp/src/utilities/core/jsoncpp.i
+        git fetch --all
+        git reset --soft v3.8.0,HEAD
 
     - uses: actions/setup-python@v5
       with:
@@ -197,30 +193,30 @@ jobs:
     - name: build nuget for Windows
       if: runner.os == 'Windows'
       run: |
-        dotnet pack ./build/csharp_wrapper/OpenStudio.csproj -o ./build/Products/csharp/Release/
+        dotnet pack ./build/csharp_wrapper/OpenStudio.csproj -o ./build/Products/csharp/Release/ -v normal
 
     - name: build nuget for Linux
       if: runner.os == 'Linux'
       run: |
         cp ./csharp/*.targets ./build/Products
         ls ./build/Products
-        dotnet pack ./build/csharp_wrapper/OpenStudio.csproj -o ./build/Products/csharp/Release/
+        dotnet pack ./build/csharp_wrapper/OpenStudio.csproj -o ./build/Products/csharp/Release/ -v normal
 
     - name: Fix dylib and build nuget for Mac
       if: runner.os == 'macOS'
       run: |
         sudo install_name_tool -add_rpath "@loader_path/." ./build/Products/libopenstudio_csharp.dylib
-        sudo install_name_tool -delete_rpath "/Users/runner/work/OpenStudio/OpenStudio/build/Products"  ./build/Products/libopenstudio_csharp.dylib
+        sudo install_name_tool -delete_rpath "${{ github.workspace }}/build/Products"  ./build/Products/libopenstudio_csharp.dylib
 
         sudo install_name_tool -add_rpath "@loader_path/." ./build/Products/libopenstudio_model_csharp.dylib
-        sudo install_name_tool -delete_rpath "/Users/runner/work/OpenStudio/OpenStudio/build/Products"  ./build/Products/libopenstudio_model_csharp.dylib
+        sudo install_name_tool -delete_rpath "${{ github.workspace }}/build/Products"  ./build/Products/libopenstudio_model_csharp.dylib
 
         sudo install_name_tool -add_rpath "@loader_path/." ./build/Products/libopenstudio_translators_csharp.dylib
-        sudo install_name_tool -delete_rpath "/Users/runner/work/OpenStudio/OpenStudio/build/Products"  ./build/Products/libopenstudio_translators_csharp.dylib
+        sudo install_name_tool -delete_rpath "${{ github.workspace }}/build/Products"  ./build/Products/libopenstudio_translators_csharp.dylib
 
         cp ./csharp/*.targets ./build/Products
         ls ./build/Products
-        dotnet pack ./build/csharp_wrapper/OpenStudio.csproj -o ./build/Products/csharp/Release/
+        dotnet pack ./build/csharp_wrapper/OpenStudio.csproj -o ./build/Products/csharp/Release/ -v normal
 
 
     - name: list files
@@ -351,7 +347,7 @@ jobs:
         dotnet test OpenStudio.Tests.x86.csproj --arch x86
 
   Test_Mac_ubuntu:
-    name: "Test x64 nuget packages for macos and ubuntu"
+    name: "Test 64-bit nuget packages for macos and ubuntu"
     runs-on: ${{ matrix.os }}
     strategy:
       # fail-fast: Default is true, switch to false to allow one platform to fail and still run others
@@ -361,10 +357,14 @@ jobs:
         include:
         - name: Ubuntu
           os: ubuntu-latest
+          arch: x64
         - name: macOS
           os: macos-13
+          arch: x64
         - name: macOS_arm64
           os: macos-14
+          arch: arm64
+
     timeout-minutes: 20
     needs: build-csharp
 
@@ -389,4 +389,4 @@ jobs:
         dotnet add OpenStudio.Tests.csproj package OpenStudio -s "./../../../nuget"
 
         dotnet clean OpenStudio.Tests.csproj
-        dotnet test OpenStudio.Tests.csproj --arch x64
+        dotnet test OpenStudio.Tests.csproj --arch ${{ matrix.arch }} /p:Platform="${{ matrix.arch }}"
diff --git a/csharp/OpenStudio-osx-arm64.targets b/csharp/OpenStudio-osx-arm64.targets
new file mode 100644
index 00000000000..48de4701d4f
--- /dev/null
+++ b/csharp/OpenStudio-osx-arm64.targets
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Target Name="PlatformCheck" BeforeTargets="InjectReference"
+    Condition="'$(Platform)' != 'arm64'">
+    <Error  Text="$(MSBuildThisFileName) does not work correctly on '$(Platform)' platform. You need to specify platform (arm64)." />
+  </Target>
+
+  <Target Name="InjectReference" BeforeTargets="ResolveAssemblyReferences">
+    <ItemGroup>
+        <Content Include="$(MSBuildThisFileDirectory)/../runtimes/osx-arm64/native/**">
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+        </Content>
+    </ItemGroup>
+  </Target>
+</Project>
diff --git a/csharp/developer/OpenStudio/OpenStudio.csproj.in b/csharp/developer/OpenStudio/OpenStudio.csproj.in
index 355a0beca9a..7f175843945 100644
--- a/csharp/developer/OpenStudio/OpenStudio.csproj.in
+++ b/csharp/developer/OpenStudio/OpenStudio.csproj.in
@@ -33,21 +33,21 @@
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
-    <DebugType>full</DebugType> 
+    <DebugType>full</DebugType>
   </PropertyGroup>
 
 <!-- Linux:
 libopenstudio_csharp.so
 libopenstudio_model_csharp.so
 libopenstudio_translators_csharp.so
-libopenstudiolib.so 
+libopenstudiolib.so
 -->
 
 <!-- Mac:
 libopenstudio_csharp.dylib
 libopenstudio_model_csharp.dylib
 libopenstudio_translators_csharp.dylib
-libopenstudiolib.dylib 
+libopenstudiolib.dylib
 -->
 
 <!-- Windows:
@@ -58,25 +58,45 @@ openstudiolib.dll
  -->
 
   <Target Name="IncludeReferencedLibInPackage" DependsOnTargets="BuildOnlySettings;ResolveReferences">
+    <Message Text="DEBUGGING: OS=$(OS) TargetFramework=$(TargetFramework) Architecture=$(Architecture) Platform=$(Platform) RID=$(Rid)" />
+    <Message Text="DEBUGGING: is_osx1=$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::OSX))) is_osx2=$([MSBuild]::IsOsPlatform('OSX'))" />
+    <Message Text="DEBUGGING: System.Runtime.InteropServices.RuntimeInformation: OSArchitecture=$([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture), RuntimeIdentifier=$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier), OSDescription=$([System.Runtime.InteropServices.RuntimeInformation]::OSDescription)" />
+    <PropertyGroup>
+      <Rid>$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier)</Rid>
+      <IsLinux>$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Linux)))</IsLinux>
+      <IsDarwin>$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::OSX)))</IsDarwin>
+      <IsWindows>$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Windows)))</IsWindows>
+      <IsArm64>False</IsArm64>
+      <IsArm64 Condition=" '$([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture)' == 'Arm64' ">true</IsArm64>
+    </PropertyGroup>
+    <Message Text="DEBUGGING: Rid=$(Rid), IsLinux=$(IsLinux), IsDarwin=$(IsDarwin), IsWindows=$(IsWindows), IsArm64=$(IsArm64), IsNotArm64=$(IsNotArm64)" />
+    <Message Condition=" $(IsDarwin) And !$(IsArm64) " Text="Darwin not arm64" />
+    <Message Condition=" $(IsDarwin) And $(IsArm64) " Text="Darwin arm64" />
     <!-- for Windows -->
-    <ItemGroup Condition="'$(OS)' == 'Windows_NT'">
+    <ItemGroup Condition=" $(IsWindows) ">
       <TfmSpecificPackageFile Include="../Products/Release/openstudio*csharp.dll" PackagePath="lib/$(TargetFramework)" />
       <TfmSpecificPackageFile Include="../Products/Release/openstudiolib.dll" PackagePath="lib/$(TargetFramework)" />
     </ItemGroup>
 
     <!-- for Linux -->
-    <ItemGroup Condition=" '$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Linux)))' ">
+    <ItemGroup Condition=" $(IsLinux) ">
       <TfmSpecificPackageFile Include="../Products/*openstudio*csharp.so" PackagePath="runtimes/linux-x64/native" />
       <TfmSpecificPackageFile Include="../Products/*openstudiolib.so" PackagePath="runtimes/linux-x64/native" />
       <TfmSpecificPackageFile Include="../Products/OpenStudio-linux-x64.targets" PackagePath="build/OpenStudio.targets" />
     </ItemGroup>
 
     <!-- for Mac  -->
-    <ItemGroup Condition=" '$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::OSX)))' ">
+    <ItemGroup Condition=" $(IsDarwin) And !$(IsArm64) ">
       <TfmSpecificPackageFile Include="../Products/*openstudio*csharp.dylib" PackagePath="runtimes/osx-x64/native" />
       <TfmSpecificPackageFile Include="../Products/*openstudiolib.dylib" PackagePath="runtimes/osx-x64/native" />
       <TfmSpecificPackageFile Include="../Products/OpenStudio-osx-x64.targets" PackagePath="build/OpenStudio.targets" />
     </ItemGroup>
+    <ItemGroup Condition=" $(IsDarwin) And $(IsArm64) ">
+      <TfmSpecificPackageFile Include="../Products/*openstudio*csharp.dylib" PackagePath="runtimes/$(Rid)/native" />
+      <TfmSpecificPackageFile Include="../Products/*openstudiolib.dylib" PackagePath="runtimes/$(Rid)/native" />
+      <TfmSpecificPackageFile Include="../Products/OpenStudio-$(Rid).targets" PackagePath="build/OpenStudio.targets" />
+    </ItemGroup>
+
   </Target>
-  
+
 </Project>