diff --git a/README.md b/README.md
index 179377f0..d4e5063b 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ HPWHsim is configured as a CMake project. Currently, CMake is only configured to
 - Microsoft Visual Studio 2017 with Visual C++ (which can be installed after from the Microsoft Visual Studio Installer)
 - CMake 3.5 or later
 - Git
-- Btwxt 0.2.0
+- Btwxt 1.0.0
 
 ### Building HPWHsim from source
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 115a45f2..0be9497d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -10,7 +10,6 @@ add_custom_target(${PROJECT_NAME}_version_header
 )
 
 set_target_properties(${PROJECT_NAME}_version_header PROPERTIES FOLDER Dependencies/HPWHsim)
-include_directories("${PROJECT_BINARY_DIR}/src" "${PROJECT_SOURCE_DIR}/src")
 
 set(headers
   HPWHversion.in.hh
@@ -26,10 +25,13 @@ set(source
 )
 add_library(libHPWHsim ${source} ${headers})
 
+target_include_directories(libHPWHsim PUBLIC ${PROJECT_BINARY_DIR}/src ${PROJECT_SOURCE_DIR}/src)
+
+target_link_libraries( libHPWHsim PUBLIC btwxt)
+
 add_dependencies(libHPWHsim ${PROJECT_NAME}_version_header)
 
 set_target_properties(libHPWHsim PROPERTIES OUTPUT_NAME HPWHsim)
 set_target_properties(libHPWHsim PROPERTIES PDB_NAME libHPWHsim)
 target_compile_features(libHPWHsim PUBLIC cxx_std_17)
 
-target_include_directories(libHPWHsim PUBLIC ${PROJECT_SOURCE_DIR}/vendor/btwxt/src)
\ No newline at end of file
diff --git a/src/HPWH.cc b/src/HPWH.cc
index f2813efd..be7e54bf 100644
--- a/src/HPWH.cc
+++ b/src/HPWH.cc
@@ -39,7 +39,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 #include "HPWH.hh"
-#include "btwxt.h"
+#include <btwxt/btwxt.h>
 
 #include <stdarg.h>
 #include <fstream>
diff --git a/src/HPWHHeatSources.cc b/src/HPWHHeatSources.cc
index ba8986d9..33f72a4e 100644
--- a/src/HPWHHeatSources.cc
+++ b/src/HPWHHeatSources.cc
@@ -6,7 +6,7 @@
 #include <regex>
 
  // vendor
-#include "btwxt.h"
+#include <btwxt/btwxt.h>
 
 #include "HPWH.hh"
 
diff --git a/src/HPWHpresets.cc b/src/HPWHpresets.cc
index 5e1da715..80580138 100644
--- a/src/HPWHpresets.cc
+++ b/src/HPWHpresets.cc
@@ -3,7 +3,7 @@ File Containing all of the presets available in HPWHsim
 */
 
 #include "HPWH.hh"
-#include "btwxt.h"
+#include <btwxt/btwxt.h>
 
 #include <algorithm>
 
@@ -1661,10 +1661,14 @@ int HPWH::HPWHinit_presets(MODELS presetNum) {
 			3.993147, 3.713376, 3.616836, 3.710957, 3.470484, 3.264466, 3.14959
 			});
 
-		// Set up regular grid interpolator. 
-		Btwxt::GriddedData gridded_data(compressor.perfGrid, compressor.perfGridValues);
-		gridded_data.set_axis_extrap_method(2, Btwxt::Method::LINEAR); //Linearly extrapolate on Tin (F)
-		compressor.perfRGI = new Btwxt::RegularGridInterpolator(gridded_data);
+		// Set up regular grid interpolator.
+		Btwxt::GridAxis g0(compressor.perfGrid[0], "TAir", Btwxt::InterpolationMethod::linear, Btwxt::ExtrapolationMethod::constant);
+		Btwxt::GridAxis g1(compressor.perfGrid[1], "TOut", Btwxt::InterpolationMethod::linear, Btwxt::ExtrapolationMethod::constant);
+		Btwxt::GridAxis g2(compressor.perfGrid[2], "TIn", Btwxt::InterpolationMethod::linear, Btwxt::ExtrapolationMethod::linear);
+
+		std::vector<Btwxt::GridAxis> gx{ g0, g1, g2 };
+
+		compressor.perfRGI = new Btwxt::RegularGridInterpolator(gx, compressor.perfGridValues);
 		compressor.useBtwxtGrid = true;
 
 		compressor.secondaryHeatExchanger = { dF_TO_dC(10.), dF_TO_dC(15.), 27. };
diff --git a/vendor/btwxt b/vendor/btwxt
index d014b897..2a5926e9 160000
--- a/vendor/btwxt
+++ b/vendor/btwxt
@@ -1 +1 @@
-Subproject commit d014b897d878eb44289d0c112d7d80dec9bc64b8
+Subproject commit 2a5926e96b594bafbcaa7640a9cabd40b5ae043d