diff --git a/Code/CMakeLists.txt b/Code/CMakeLists.txt
index 8d00ecac8..056d52a6a 100644
--- a/Code/CMakeLists.txt
+++ b/Code/CMakeLists.txt
@@ -123,7 +123,9 @@ if (HEMELB_USE_DEBUGGER)
   set(CMAKE_BUILD_TYPE Debug)
 endif()
 
-add_executable(${HEMELB_EXECUTABLE} SimulationMaster.cc main.cc)
+add_library(hemelb_sim OBJECT SimulationMaster.cc)
+list(APPEND heme_libraries hemelb_sim)
+add_executable(${HEMELB_EXECUTABLE} main.cc)
 codesign(${HEMELB_EXECUTABLE})
 
 include_directories(${PROJECT_SOURCE_DIR})
diff --git a/Code/SimulationMaster.cc b/Code/SimulationMaster.cc
index d2bc383ee..5ac4fe0ae 100644
--- a/Code/SimulationMaster.cc
+++ b/Code/SimulationMaster.cc
@@ -37,23 +37,9 @@ namespace hemelb
      * Initialises member variables including the network topology
      * object.
      */
-    SimulationMaster::SimulationMaster(configuration::CommandLine & options,
-                                               const net::IOCommunicator& ioComm) :
+    SimulationMaster::SimulationMaster(const net::IOCommunicator& ioComm) :
             build_info(), ioComms(ioComm.Duplicate()), communicationNet(ioComms)
     {
-        // Start the main timer!
-        timings.total().Start();
-
-        fileManager = std::make_shared<io::PathManager>(options,
-                                                                IsCurrentProcTheIOProc(),
-                                                                GetProcessorCount());
-        log::Logger::Log<log::Info, log::Singleton>("Reading configuration from %s", fileManager->GetInputFile().c_str());
-        // Convert XML to configuration
-        simConfig = configuration::SimConfig::New(fileManager->GetInputFile());
-        // Use it to initialise self
-        auto builder = configuration::SimBuilder(simConfig);
-        log::Logger::Log<log::Info, log::Singleton>("Beginning Initialisation.");
-        builder.build<>(*this);
     }
 
   /// Destructor for the SimulationMaster class.
diff --git a/Code/SimulationMaster.h b/Code/SimulationMaster.h
index fb3182225..e71e7d6c1 100644
--- a/Code/SimulationMaster.h
+++ b/Code/SimulationMaster.h
@@ -16,7 +16,7 @@
 #include "util/UnitConverter.h"
 #include "configuration/SimConfig.h"
 #include "configuration/CommandLine.h"
-#include "io/PathManager.h"
+#include "configuration/PathManager.h"
 #include "reporting/Reporter.h"
 #include "reporting/Timers.h"
 #include "reporting/BuildInfo.h"
@@ -53,7 +53,7 @@ namespace hemelb
         std::shared_ptr<lb::LBMBase> latticeBoltzmannModel;
         std::shared_ptr<geometry::neighbouring::NeighbouringDataManager> neighbouringDataManager;
 
-        std::shared_ptr<io::PathManager> fileManager;
+        std::shared_ptr<configuration::PathManager> fileManager;
         std::shared_ptr<reporting::Reporter> reporter;
 
         std::shared_ptr<lb::SimulationState> simulationState;
@@ -77,9 +77,8 @@ namespace hemelb
         std::shared_ptr<net::phased::StepManager> stepManager;
         std::shared_ptr<net::phased::NetConcern> netConcern;
 
+        SimulationMaster(const net::IOCommunicator& ioComm);
     public:
-      SimulationMaster(configuration::CommandLine &options,
-                       const net::IOCommunicator& ioComms);
       virtual ~SimulationMaster();
 
       void Abort();
diff --git a/Code/configuration/CMakeLists.txt b/Code/configuration/CMakeLists.txt
index fee5df7de..9f07717d4 100644
--- a/Code/configuration/CMakeLists.txt
+++ b/Code/configuration/CMakeLists.txt
@@ -5,6 +5,7 @@
 
 add_library(hemelb_configuration OBJECT
         CommandLine.cc
+        PathManager.cc
         SimConfig.cc
         SimBuilder.cc
         SimConfigReader.cc
diff --git a/Code/io/PathManager.cc b/Code/configuration/PathManager.cc
similarity index 97%
rename from Code/io/PathManager.cc
rename to Code/configuration/PathManager.cc
index 0950481cb..e4facf2d8 100644
--- a/Code/io/PathManager.cc
+++ b/Code/configuration/PathManager.cc
@@ -3,13 +3,13 @@
 // file AUTHORS. This software is provided under the terms of the
 // license in the file LICENSE.
 
-#include "io/PathManager.h"
+#include "configuration/PathManager.h"
 
 #include "Exception.h"
 #include "configuration/CommandLine.h"
 
 namespace fs = std::filesystem;
-namespace hemelb::io
+namespace hemelb::configuration
 {
 
     PathManager::PathManager(const configuration::CommandLine & commandLine, const bool & io,
diff --git a/Code/io/PathManager.h b/Code/configuration/PathManager.h
similarity index 93%
rename from Code/io/PathManager.h
rename to Code/configuration/PathManager.h
index 92e4c13de..43740db24 100644
--- a/Code/io/PathManager.h
+++ b/Code/configuration/PathManager.h
@@ -3,8 +3,8 @@
 // file AUTHORS. This software is provided under the terms of the
 // license in the file LICENSE.
 
-#ifndef HEMELB_IO_PATHMANAGER_H
-#define HEMELB_IO_PATHMANAGER_H
+#ifndef HEMELB_CONFIGURATION_PATHMANAGER_H
+#define HEMELB_CONFIGURATION_PATHMANAGER_H
 
 #include <filesystem>
 #include <string>
@@ -14,12 +14,6 @@ namespace hemelb::configuration
 {
     class CommandLine;
     class SimConfig;
-}
-
-namespace hemelb::io
-{
-    // Forward declare the Writer
-    namespace writers { class Writer; }
 
     /**
      * Manage the input and output file system locations for HemeLB reports, extracted data, and input xml.
@@ -82,4 +76,4 @@ namespace hemelb::io
 
 }
 
-#endif //HEMELB_IO_PATHMANAGER_H
+#endif //HEMELB_CONFIGURATION_PATHMANAGER_H
diff --git a/Code/configuration/SimBuilder.cc b/Code/configuration/SimBuilder.cc
index 5082a7b29..56ea9fcf7 100644
--- a/Code/configuration/SimBuilder.cc
+++ b/Code/configuration/SimBuilder.cc
@@ -291,7 +291,7 @@ namespace hemelb::configuration {
     }
 
     std::shared_ptr<reporting::Reporter> SimBuilder::BuildReporter(
-            io::PathManager const& fileManager,
+            PathManager const& fileManager,
             std::vector<reporting::Reportable*>const& reps
     ) const {
         auto reporter = std::make_shared<reporting::Reporter>(fileManager.GetReportPath(),
diff --git a/Code/configuration/SimBuilder.h b/Code/configuration/SimBuilder.h
index bb93a2075..001961e5a 100644
--- a/Code/configuration/SimBuilder.h
+++ b/Code/configuration/SimBuilder.h
@@ -54,6 +54,31 @@ namespace hemelb::configuration {
         std::shared_ptr<util::UnitConverter> unit_converter;
 
     public:
+        template <typename TraitsT>
+        static std::unique_ptr<SimulationMaster> CreateSim(
+                CommandLine const& options,
+                net::IOCommunicator const& ioComms
+        ) {
+            auto ans = std::unique_ptr<SimulationMaster>(new SimulationMaster(ioComms));
+            // Start the main timer!
+            ans->timings.total().Start();
+
+            ans->fileManager = std::make_shared<configuration::PathManager>(
+                    options,
+                    ioComms.OnIORank(),
+                    ioComms.Size()
+            );
+            auto&& infile = ans->fileManager->GetInputFile();
+            log::Logger::Log<log::Info, log::Singleton>("Reading configuration from %s", infile.c_str());
+            // Convert XML to configuration
+            ans->simConfig = configuration::SimConfig::New(infile);
+            // Use it to initialise self
+            auto builder = configuration::SimBuilder(ans->simConfig);
+            log::Logger::Log<log::Info, log::Singleton>("Beginning Initialisation.");
+            builder.build<TraitsT>(*ans);
+            return ans;
+        }
+
         explicit SimBuilder(SimConfig const& conf, bool construct_unit_converter = true);
         virtual ~SimBuilder() = default;
 
@@ -111,7 +136,7 @@ namespace hemelb::configuration {
         ) const;
 
         [[nodiscard]] std::shared_ptr<reporting::Reporter> BuildReporter(
-                io::PathManager const& fileManager,
+                PathManager const& fileManager,
                 std::vector<reporting::Reportable*> const & reps
         ) const;
     };
@@ -299,8 +324,6 @@ namespace hemelb::configuration {
     [[nodiscard]] std::shared_ptr<net::IteratedAction> SimBuilder::BuildCellController(SimulationMaster const& control, reporting::Timers& timings) const {
         if (config.HasRBCSection()) {
 #ifdef HEMELB_BUILD_RBC
-            using traitsType = typename T::Traits;
-
             auto ccb = redblood::CellControllerBuilder(unit_converter);
 
             auto& ioComms = control.ioComms;
@@ -324,4 +347,4 @@ namespace hemelb::configuration {
         return {};
     }
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/Code/extraction/PropertyActor.h b/Code/extraction/PropertyActor.h
index 9820fdc4f..1aad55199 100644
--- a/Code/extraction/PropertyActor.h
+++ b/Code/extraction/PropertyActor.h
@@ -7,7 +7,6 @@
 #define HEMELB_EXTRACTION_PROPERTYACTOR_H
 
 #include "extraction/PropertyWriter.h"
-#include "io/PathManager.h"
 #include "lb/MacroscopicPropertyCache.h"
 #include "lb/SimulationState.h"
 #include "net/IteratedAction.h"
diff --git a/Code/io/CMakeLists.txt b/Code/io/CMakeLists.txt
index d95ce1720..73144588d 100644
--- a/Code/io/CMakeLists.txt
+++ b/Code/io/CMakeLists.txt
@@ -12,7 +12,6 @@ endif()
 
 add_library(hemelb_io OBJECT
   FILE.cc
-  PathManager.cc 
   writers/AsciiFileWriter.cc writers/AsciiStreamWriter.cc
   readers/XdrFileReader.cc
   readers/XdrMemReader.cc
diff --git a/Code/io/Checkpointer.h b/Code/io/Checkpointer.h
index 89604c679..4ec2e6c61 100644
--- a/Code/io/Checkpointer.h
+++ b/Code/io/Checkpointer.h
@@ -9,7 +9,7 @@
 #include <filesystem>
 #include <memory>
 
-#include "io/PathManager.h"
+#include "configuration/SimConfig.h"
 #include "io/TimePattern.h"
 #include "lb/SimulationState.h"
 #include "net/IteratedAction.h"
diff --git a/Code/main.cc b/Code/main.cc
index ba5286406..7664a348f 100644
--- a/Code/main.cc
+++ b/Code/main.cc
@@ -6,9 +6,9 @@
 #include "net/mpi.h"
 #include "net/IOCommunicator.h"
 #include "configuration/CommandLine.h"
+#include "configuration/SimBuilder.h"
 #include "io/ensure_hexfloat.h"
 #include "debug.h"
-#include "SimulationMaster.h"
 
 int main(int argc, char *argv[])
 {
@@ -40,10 +40,10 @@ int main(int argc, char *argv[])
       debug::Init(options.GetDebug(), argv[0], commWorld);
 
       // Prepare main simulation object...
-      SimulationMaster master(options, hemelbCommunicator);
+      auto master = configuration::SimBuilder::CreateSim<Traits<>>(options, hemelbCommunicator);
 
       // ..and run it.
-      master.RunSimulation();
+      master->RunSimulation();
     }
 
     // Interpose this catch to print usage before propagating the error.
diff --git a/Code/multiscale/MultiscaleSimulationMaster.h b/Code/multiscale/MultiscaleSimulationMaster.h
index 30394fe3f..a0491312d 100644
--- a/Code/multiscale/MultiscaleSimulationMaster.h
+++ b/Code/multiscale/MultiscaleSimulationMaster.h
@@ -199,7 +199,7 @@ namespace hemelb::multiscale
           }
         }
 
-        void DoTimeStep()
+        void DoTimeStep() override
         {
           bool advance = intercomms.DoMultiscale(GetState().GetTime());
           log::Logger::Log<log::Info, log::Singleton>("At time step %i, should advance %i, time %f",
diff --git a/Code/net/IOCommunicator.h b/Code/net/IOCommunicator.h
index dd8225609..fdab1854f 100644
--- a/Code/net/IOCommunicator.h
+++ b/Code/net/IOCommunicator.h
@@ -27,6 +27,7 @@ namespace hemelb::net {
     public:
         static constexpr int IO_RANK = 0;
 
+        IOCommunicator() = default;
         explicit IOCommunicator(const MpiCommunicator& comm);
 
         inline bool OnIORank() const {
diff --git a/Code/redblood/CellArmy.h b/Code/redblood/CellArmy.h
index 4b74b3011..8d7e698c7 100644
--- a/Code/redblood/CellArmy.h
+++ b/Code/redblood/CellArmy.h
@@ -324,8 +324,8 @@ namespace hemelb
           log::Logger::Log<log::Info, log::OnePerCore>(message.str());
 
           cellDnC.remove(*i_current);
-          cells.erase(i_current);
           auto const numErased = nodeDistributions.erase((*i_current)->GetTag());
+          cells.erase(i_current);
           assert(numErased == 1);
         }
       }
diff --git a/Code/redblood/CellControllerBuilder.cc b/Code/redblood/CellControllerBuilder.cc
index c2b622f69..1f05a503a 100644
--- a/Code/redblood/CellControllerBuilder.cc
+++ b/Code/redblood/CellControllerBuilder.cc
@@ -5,7 +5,7 @@
 
 #include "redblood/CellControllerBuilder.h"
 
-#include "io/PathManager.h"
+#include "configuration/PathManager.h"
 #include "redblood/CellIO.h"
 #include "redblood/FaderCell.h"
 #include "redblood/MeshIO.h"
@@ -350,7 +350,7 @@ namespace hemelb::redblood {
     CellChangeListener CellControllerBuilder::build_full_cell_output(
             configuration::CellOutputConfig const& conf,
             std::shared_ptr<lb::SimulationState const> simState,
-            std::shared_ptr<io::PathManager const> fileManager,
+            std::shared_ptr<configuration::PathManager const> fileManager,
             net::IOCommunicator const& ioComms
     ) const {
         auto conv = conf.physical_units ? unit_converter : nullptr;
@@ -360,7 +360,7 @@ namespace hemelb::redblood {
     CellChangeListener CellControllerBuilder::build_summary_cell_output(
             configuration::CellOutputConfig const& conf,
             std::shared_ptr<lb::SimulationState const> simState,
-            std::shared_ptr<io::PathManager const> fileManager,
+            std::shared_ptr<configuration::PathManager const> fileManager,
             net::IOCommunicator const& ioComms
     ) const {
         auto conv = conf.physical_units ? unit_converter : nullptr;
diff --git a/Code/redblood/CellControllerBuilder.h b/Code/redblood/CellControllerBuilder.h
index 2eb787f10..1c6d21a23 100644
--- a/Code/redblood/CellControllerBuilder.h
+++ b/Code/redblood/CellControllerBuilder.h
@@ -17,7 +17,7 @@
 #include "redblood/CellController.h"
 #include "redblood/RBCInserter.h"
 
-namespace hemelb::io { class PathManager; }
+namespace hemelb::configuration { class PathManager; }
 
 namespace hemelb::redblood {
 
@@ -86,13 +86,13 @@ namespace hemelb::redblood {
         CellChangeListener build_full_cell_output(
                 configuration::CellOutputConfig const& conf,
                 std::shared_ptr<lb::SimulationState const> simState,
-                std::shared_ptr<io::PathManager const> fileManager,
+                std::shared_ptr<configuration::PathManager const> fileManager,
                 net::IOCommunicator const& ioComms
         ) const;
         CellChangeListener build_summary_cell_output(
                 configuration::CellOutputConfig const& conf,
                 std::shared_ptr<lb::SimulationState const> simState,
-                std::shared_ptr<io::PathManager const> fileManager,
+                std::shared_ptr<configuration::PathManager const> fileManager,
                 net::IOCommunicator const& ioComms
         ) const;
 
@@ -104,7 +104,7 @@ namespace hemelb::redblood {
                                                    CountedIoletView const& inlets,
                                                    CountedIoletView const& outlets,
                                                    std::shared_ptr<lb::SimulationState const> simState,
-                                                   std::shared_ptr<io::PathManager const> fileManager
+                                                   std::shared_ptr<configuration::PathManager const> fileManager
         ) {
             log::Logger::Log<log::Info, log::Singleton>("Initialising RBCs.");
             timings.cellInitialisation().Start();
diff --git a/Code/redblood/CellIO.cc b/Code/redblood/CellIO.cc
index dcf15533a..325234c90 100644
--- a/Code/redblood/CellIO.cc
+++ b/Code/redblood/CellIO.cc
@@ -9,8 +9,8 @@
 #include <cstring>
 #include <boost/uuid/uuid_io.hpp>
 
+#include "configuration/PathManager.h"
 #include "io/formats/rbc.h"
-#include "io/PathManager.h"
 #include "io/writers/XdrWriter.h"
 #include "io/readers/XdrFileReader.h"
 #include "io/readers/XdrMemReader.h"
@@ -21,6 +21,7 @@
 #include "redblood/FaderCell.h"
 #include "redblood/MeshIO.h"
 #include "util/Iterator.h"
+#include "util/span.h"
 
 namespace hemelb::redblood {
 
@@ -74,7 +75,7 @@ namespace hemelb::redblood {
     CellBarycentreOutput::CellBarycentreOutput(hemelb::LatticeTimeStep period,
                                                std::shared_ptr<const util::UnitConverter> unitConverter,
                                                std::shared_ptr<const lb::SimulationState> simState,
-                                               std::shared_ptr<const io::PathManager> fileManager,
+                                               std::shared_ptr<const configuration::PathManager> fileManager,
                                                net::IOCommunicator comms) :
             CellOutputBase{
                     period, std::move(unitConverter), std::move(simState), std::move(fileManager), comms
@@ -134,7 +135,7 @@ namespace hemelb::redblood {
         const std::size_t local_write_start = ioComms.OnIORank() ? 0 : (fmt::rbc::header_size + n_cells_before_me * fmt::rbc::row_size);
 
         auto bary_file = net::MpiFile::Open(ioComms, bary_filename, MPI_MODE_WRONLY | MPI_MODE_CREATE | MPI_MODE_EXCL);
-        bary_file.WriteAt(local_write_start, buffer);
+        bary_file.WriteAt(local_write_start, to_const_span(buffer));
         bary_file.Close();
     }
 
@@ -172,7 +173,7 @@ namespace hemelb::redblood {
         auto read_size = n * fmt::rbc::row_size;
 
         std::vector<std::byte> read_buf(read_size);
-        inputFile.ReadAt(read_start, read_buf);
+        inputFile.ReadAt(read_start, to_span(read_buf));
         auto reader = io::XdrMemReader(read_buf);
         std::vector<row> ans(n);
         boost::uuids::string_generator gen;
diff --git a/Code/redblood/CellIO.h b/Code/redblood/CellIO.h
index 7906824d8..76211452b 100644
--- a/Code/redblood/CellIO.h
+++ b/Code/redblood/CellIO.h
@@ -15,7 +15,7 @@
 #include "net/IOCommunicator.h"
 #include "redblood/types_fwd.h"
 
-namespace hemelb::io { class PathManager; }
+namespace hemelb::configuration { class PathManager; }
 namespace hemelb::lb { class SimulationState; }
 namespace hemelb::util { class UnitConverter; }
 
@@ -30,7 +30,7 @@ namespace hemelb::redblood {
         // nullptr => use lattice units
         std::shared_ptr<util::UnitConverter const> unitConverter;
         std::shared_ptr<lb::SimulationState const> simState;
-        std::shared_ptr<io::PathManager const> fileManager;
+        std::shared_ptr<configuration::PathManager const> fileManager;
         net::IOCommunicator ioComms;
     };
 
@@ -46,7 +46,7 @@ namespace hemelb::redblood {
                 LatticeTimeStep period,
                 std::shared_ptr<util::UnitConverter const> unitConverter,
                 std::shared_ptr<lb::SimulationState const> simState,
-                std::shared_ptr<io::PathManager const> fileManager,
+                std::shared_ptr<configuration::PathManager const> fileManager,
                 net::IOCommunicator comms
         );
 
diff --git a/Code/redblood/VelocityInterpolation.h b/Code/redblood/VelocityInterpolation.h
index 14e487fb8..446b34842 100644
--- a/Code/redblood/VelocityInterpolation.h
+++ b/Code/redblood/VelocityInterpolation.h
@@ -83,7 +83,7 @@ namespace hemelb::redblood
                   // Follows approach in Timm's code
                   return latticeData.GetFNew<LatticeType>(index);
               } else {
-                  return site.GetFOld<LatticeType>();
+                  return site.template GetFOld<LatticeType>();
               }
         }();
         LatticeType::CalculateDensityAndMomentum(fDistribution,
diff --git a/Code/redblood/WallCellPairIterator.h b/Code/redblood/WallCellPairIterator.h
index 7057a7720..71b443ef5 100644
--- a/Code/redblood/WallCellPairIterator.h
+++ b/Code/redblood/WallCellPairIterator.h
@@ -110,7 +110,8 @@ namespace hemelb::redblood
         pointer operator->() const
         {
             HASSERT(static_cast<bool>(*this));
-            return std::make_unique<value_type>(*firstCellNode, firstWallNode->second.node);
+            value_type tmp{*firstCellNode, firstWallNode->second.node};
+            return std::make_unique<value_type>(tmp);
         }
 
         bool operator++();
diff --git a/Code/redblood/parallel/GraphBasedCommunication.cc b/Code/redblood/parallel/GraphBasedCommunication.cc
index 058280dd3..1e0f33073 100644
--- a/Code/redblood/parallel/GraphBasedCommunication.cc
+++ b/Code/redblood/parallel/GraphBasedCommunication.cc
@@ -83,8 +83,7 @@ namespace hemelb::redblood::parallel
         auto rank = comm.Rank();
 
         // Loop over this process's edge
-        auto first_edge_site_i = domain.GetMidDomainSiteCount();
-        auto last_edge_site_i = first_edge_site_i + domain.GetDomainEdgeSiteCount();
+        auto [first_edge_site_i, last_edge_site_i] = domain.GetAllDomainEdgeSiteRange();
         for (auto siteIndex = first_edge_site_i;
              siteIndex < last_edge_site_i;
              ++siteIndex) {
diff --git a/Code/reporting/Reportable.h b/Code/reporting/Reportable.h
index 20d210633..2839cd21a 100644
--- a/Code/reporting/Reportable.h
+++ b/Code/reporting/Reportable.h
@@ -8,20 +8,18 @@
 
 #include "reporting/Dict.h"
 
-namespace hemelb
+
+namespace hemelb::reporting
 {
-  namespace reporting
-  {
     /**
      * Defines the interface for classes that can have entries in reports.
      */
     class Reportable
     {
-      public:
+    public:
         virtual ~Reportable() noexcept = default;
         virtual void Report(Dict& dictionary) = 0;
     };
-  }
 }
 
 #endif /* HEMELB_REPORTING_REPORTABLE_H */
diff --git a/Code/tests/CMakeLists.txt b/Code/tests/CMakeLists.txt
index 4023a0ee6..ed27a2939 100644
--- a/Code/tests/CMakeLists.txt
+++ b/Code/tests/CMakeLists.txt
@@ -42,9 +42,6 @@ add_to_resources(resources/four_cube.gmy resources/four_cube.xml resources/four_
   resources/large_cylinder.gmy resources/large_cylinder.xml
 )
 
-if (HEMELB_BUILD_MULTISCALE)
-  add_to_resources(multiscale/mpwide/MPWSettings.cfg)
-endif()
 
 add_test_executable(hemelb-tests main.cc SimulationMasterTests.cc)
 
@@ -60,11 +57,15 @@ add_to_tests(extraction)
 add_to_tests(geometry)
 add_to_tests(io)
 add_to_tests(lb)
-add_to_tests(multiscale)
 add_to_tests(net)
 add_to_tests(reporting)
 add_to_tests(util)
 
+if (HEMELB_BUILD_MULTISCALE)
+  add_to_resources(multiscale/mpwide/MPWSettings.cfg)
+  add_to_tests(multiscale)
+endif()
+
 if (HEMELB_BUILD_RBC)
   add_to_resources(
     resources/red_blood_cell.txt resources/red_blood_cube.txt
diff --git a/Code/tests/SimulationMasterTests.cc b/Code/tests/SimulationMasterTests.cc
index 4889c95fb..1399f8f25 100644
--- a/Code/tests/SimulationMasterTests.cc
+++ b/Code/tests/SimulationMasterTests.cc
@@ -6,7 +6,7 @@
 
 #include <catch2/catch.hpp>
 
-#include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 
 #include "tests/helpers/FolderTestFixture.h"
 #include "tests/helpers/LaddFail.h"
@@ -27,7 +27,7 @@ namespace hemelb::tests
       CopyResourceToTempdir("four_cube.gmy");
 
       auto options = std::make_unique<hemelb::configuration::CommandLine>(argc, argv);
-      auto master = std::make_unique<SimulationMaster>(*options, Comms());
+      auto master = configuration::SimBuilder::CreateSim<Traits<>>(*options, Comms());
 
       SECTION("Running a simulation creates outputs") {
 	// TODO: This test is fatal if run with LADDIOLET. See ticket #605.
diff --git a/Code/tests/configuration/CMakeLists.txt b/Code/tests/configuration/CMakeLists.txt
index 49071db6b..57c9ddb80 100644
--- a/Code/tests/configuration/CMakeLists.txt
+++ b/Code/tests/configuration/CMakeLists.txt
@@ -5,4 +5,5 @@
 add_test_lib(test_configuration
   CommandLineTests.cc
   SimConfigTests.cc
+  PathManagerTests.cc
   )
diff --git a/Code/tests/io/PathManagerTests.cc b/Code/tests/configuration/PathManagerTests.cc
similarity index 88%
rename from Code/tests/io/PathManagerTests.cc
rename to Code/tests/configuration/PathManagerTests.cc
index 44b764168..f0845d7b0 100644
--- a/Code/tests/io/PathManagerTests.cc
+++ b/Code/tests/configuration/PathManagerTests.cc
@@ -8,7 +8,7 @@
 #include <catch2/catch.hpp>
 
 #include "configuration/CommandLine.h"
-#include "io/PathManager.h"
+#include "configuration/PathManager.h"
 
 #include "tests/helpers/FolderTestFixture.h"
 
@@ -17,7 +17,7 @@ namespace fs = std::filesystem;
 namespace hemelb::tests
 {
 
-    std::unique_ptr<io::PathManager> setup(const char* confXml) {
+    std::unique_ptr<configuration::PathManager> setup(const char* confXml) {
         const int processorCount = 5;
         const int argc = 3;
         const char* argv[] = {
@@ -27,7 +27,7 @@ namespace hemelb::tests
         };
 
         auto cl = configuration::CommandLine(argc, argv);
-        return std::make_unique<io::PathManager>(cl, true, processorCount);
+        return std::make_unique<configuration::PathManager>(cl, true, processorCount);
     }
 
     TEST_CASE_METHOD(helpers::FolderTestFixture, "PathManager") {
diff --git a/Code/tests/io/CMakeLists.txt b/Code/tests/io/CMakeLists.txt
index ac8b66a40..074933d5c 100644
--- a/Code/tests/io/CMakeLists.txt
+++ b/Code/tests/io/CMakeLists.txt
@@ -4,7 +4,6 @@
 # license in the file LICENSE.
 add_test_lib(test_io
   xdr_test_data.cc
-  PathManagerTests.cc
   XdrWriterTests.cc
   XdrReaderTests.cc
   xml.cc
diff --git a/Code/tests/redblood/CellArmyTests.cc b/Code/tests/redblood/CellArmyTests.cc
index 3130b90b4..a03b27854 100644
--- a/Code/tests/redblood/CellArmyTests.cc
+++ b/Code/tests/redblood/CellArmyTests.cc
@@ -16,11 +16,11 @@
 namespace hemelb::tests
 {
     //! Mock cell for ease of use
-    class FakeCell : public hemelb::redblood::Cell
+    class FakeCell : public redblood::Cell
     {
     public:
         mutable size_t nbcalls = 0;
-        using hemelb::redblood::Cell::Cell;
+        using redblood::Cell::Cell;
         //! Facet bending energy
         LatticeEnergy operator()() const override
         {
@@ -38,7 +38,7 @@ namespace hemelb::tests
       using namespace redblood;
 
       LatticeDistance const cutoff = 5.0;
-        using Traits = hemelb::Traits<lb::D3Q15, lb::GuoForcingLBGK, lb::Normal,
+        using Traits = Traits<lb::D3Q15, lb::GuoForcingLBGK, lb::Normal,
                 lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
                 stencil::FourPoint>;
 
diff --git a/Code/tests/redblood/CellIOTests.cc b/Code/tests/redblood/CellIOTests.cc
index 63b0fac37..439085132 100644
--- a/Code/tests/redblood/CellIOTests.cc
+++ b/Code/tests/redblood/CellIOTests.cc
@@ -203,7 +203,7 @@ namespace hemelb::tests
                 cells.insert(cell);
                 auto outConf = configuration::CellOutputConfig{10, false};
                 configuration::CommandLine cmdline({"hemelb", "-in", "empty_for_relative_paths.xml"});
-                auto pathmgr = std::make_shared<io::PathManager>(cmdline, Comms().OnIORank(), Comms().Size());
+                auto pathmgr = std::make_shared<configuration::PathManager>(cmdline, Comms().OnIORank(), Comms().Size());
                 auto simState = std::make_shared<lb::SimulationState>(0.1, 1000);
                 auto full_out = cell_builder.build_full_cell_output(outConf, simState, pathmgr, Comms());
                 auto summ_out = cell_builder.build_summary_cell_output(outConf, simState, pathmgr, Comms());
@@ -215,7 +215,7 @@ namespace hemelb::tests
                 // Check barycentre
                 auto bary_path = fs::path{"results/Cells/0/barycentres.rbc"};
                 REQUIRE(fs::exists(bary_path));
-                auto bci = CellBarycentreInput(bary_path);
+                auto bci = CellBarycentreInput{bary_path};
                 auto ncells = bci.ReadHeader();
                 REQUIRE(ncells == 1);
                 auto cell_summary = bci.ReadRows(Comms(), 0, 1);
diff --git a/Code/tests/redblood/CellIntegrationTests.cc b/Code/tests/redblood/CellIntegrationTests.cc
index 4d7cc2eb1..42a9366ec 100644
--- a/Code/tests/redblood/CellIntegrationTests.cc
+++ b/Code/tests/redblood/CellIntegrationTests.cc
@@ -8,9 +8,9 @@
 
 #include "Traits.h"
 #include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "redblood/Cell.h"
 #include "redblood/CellController.h"
-#include "tests/redblood/Fixtures.h"
 #include "tests/helpers/LatticeDataAccess.h"
 #include "tests/helpers/FolderTestFixture.h"
 
@@ -21,7 +21,6 @@ namespace hemelb::tests
     {
       using MyTraits = Traits<lb::DefaultLattice, lb::GuoForcingLBGK>;
       using CellControll = CellController<MyTraits>;
-      using MasterSim = SimulationMaster<MyTraits>;
 
     public:
       CellIntegrationTests() : FolderTestFixture(), timings() {
@@ -31,16 +30,16 @@ namespace hemelb::tests
 	CopyResourceToTempdir("large_cylinder.xml");
     ModifyXMLInput("large_cylinder.xml", {"simulation", "steps", "value"}, 8);
 	CopyResourceToTempdir("large_cylinder.gmy");
-	options = std::make_shared<hemelb::configuration::CommandLine>(argc, argv);
+	options = std::make_unique<configuration::CommandLine>(argc, argv);
 
 	auto cell = std::make_shared<Cell>(icoSphere(4));
-	templates = std::make_shared<TemplateCellContainer>();
+	templates = std::make_unique<TemplateCellContainer>();
 	(*templates)["icosphere"] = cell;
 	cell->moduli = Cell::Moduli(1e-6, 1e-6, 1e-6, 1e-6);
 	cells.insert(cell);
 
 	//timings = std::make_unique<reporting::Timers>(Comms());
-	master = std::make_shared<MasterSim>(*options, Comms());
+	master = configuration::SimBuilder::CreateSim<MyTraits>(*options, Comms());
 	helpers::LatticeDataAccess(&master->GetFieldData()).ZeroOutForces();
       }
 
@@ -120,8 +119,8 @@ namespace hemelb::tests
       }
 
     private:
-      std::shared_ptr<MasterSim> master;
-      std::shared_ptr<configuration::CommandLine> options;
+      std::unique_ptr<SimulationMaster> master;
+      std::unique_ptr<configuration::CommandLine> options;
       CellContainer cells;
       std::shared_ptr<TemplateCellContainer> templates;
       reporting::Timers timings;
diff --git a/Code/tests/redblood/FadeInOutIntegrationTests.cc b/Code/tests/redblood/FadeInOutIntegrationTests.cc
index 0e4c33392..1ed6a00d6 100644
--- a/Code/tests/redblood/FadeInOutIntegrationTests.cc
+++ b/Code/tests/redblood/FadeInOutIntegrationTests.cc
@@ -4,10 +4,10 @@
 // license in the file LICENSE.
 
 #include <memory>
-#include <boost/uuid/uuid_io.hpp>
 #include <catch2/catch.hpp>
 
 #include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "lb/lattices/D3Q19.h"
 #include "Traits.h"
 #include "redblood/Mesh.h"
@@ -23,7 +23,6 @@ namespace hemelb::tests
                      "[redblood][.long]") {
         using Traits = Traits<lb::D3Q19, lb::GuoForcingLBGK>;
         using CellControl = CellController<Traits>;
-        using MasterSim = SimulationMaster<Traits>;
 
       CopyResourceToTempdir("large_cylinder_rbc.xml");
       CopyResourceToTempdir("large_cylinder.gmy");
@@ -45,15 +44,15 @@ namespace hemelb::tests
 	"hemelb", "-in", "large_cylinder_rbc.xml",
       };
 
-      auto options = hemelb::configuration::CommandLine{argc, argv};
-      auto master = std::make_shared<MasterSim>(options, Comms());
+      auto options = configuration::CommandLine{argc, argv};
+      auto master = configuration::SimBuilder::CreateSim<Traits>(options, Comms());
      
       SECTION("testIntegration") {
 	auto const & converter = master->GetUnitConverter();
 	auto const volumeFactor = std::pow(converter.ConvertToLatticeUnits("m", 1e0), -3)
 	  * 1e12;
 	bool didDropCell = false;
-	auto checkDidDropCell = [&didDropCell](const hemelb::redblood::CellContainer & cells)
+	auto checkDidDropCell = [&didDropCell](const CellContainer & cells)
 	  {
 	    didDropCell |= not cells.empty();
 	  };
@@ -149,7 +148,7 @@ namespace hemelb::tests
 	AssertPresent("results/report.xml");
 	REQUIRE(iter > 0);
 	REQUIRE(didDropCell);
-	REQUIRE(0ul == controller->GetCells().size());
+	REQUIRE(controller->GetCells().empty());
       }
     }
 
diff --git a/Code/tests/redblood/FedosovValidationTests.cc b/Code/tests/redblood/FedosovValidationTests.cc
index 9b9233e26..9ae316622 100644
--- a/Code/tests/redblood/FedosovValidationTests.cc
+++ b/Code/tests/redblood/FedosovValidationTests.cc
@@ -8,6 +8,7 @@
 #include <catch2/catch.hpp>
 
 #include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "lb/lattices/D3Q19.h"
 #include "Traits.h"
 #include "redblood/MeshIO.h"
@@ -22,8 +23,7 @@ namespace hemelb::tests
     TEST_CASE_METHOD(helpers::FolderTestFixture, "Fedosov validation tests", "[redblood][.long]") {
 
       using Traits = Traits<lb::D3Q19, lb::GuoForcingLBGK>;
-      using CellControl = hemelb::redblood::CellController<Traits>;
-      using MasterSim = SimulationMaster<Traits>;
+      using CellControl = CellController<Traits>;
 
       CopyResourceToTempdir("fedosov1c.xml");
       CopyResourceToTempdir("fedosov1c.gmy");
@@ -36,7 +36,7 @@ namespace hemelb::tests
       argv[2] = "fedosov1c.xml";
 
       configuration::CommandLine options(argc, argv);
-      auto master = std::make_shared<MasterSim>(options, Comms());
+      auto master = configuration::SimBuilder::CreateSim<Traits>(options, Comms());
       redblood::VTKMeshIO vtk_io = {};
 
       SECTION("Integration test") {
@@ -44,7 +44,7 @@ namespace hemelb::tests
 	auto const & converter = master->GetUnitConverter();
 	auto controller = std::static_pointer_cast<CellControl>(master->GetCellController());
 	REQUIRE(controller);
-	controller->AddCellChangeListener([vtk_io, &converter](const hemelb::redblood::CellContainer &cells) {
+	controller->AddCellChangeListener([vtk_io, &converter](const CellContainer &cells) {
 	    static int iter = 0;
 	    if(cells.empty()) {
 	      return;
diff --git a/Code/tests/redblood/InterpolationTests.cc b/Code/tests/redblood/InterpolationTests.cc
index 39e594ae5..a87c4e900 100644
--- a/Code/tests/redblood/InterpolationTests.cc
+++ b/Code/tests/redblood/InterpolationTests.cc
@@ -311,11 +311,12 @@ namespace hemelb::tests
 
 	//KERNEL kernel(initParams);
 	VelocityFromLatticeData<KERNEL> velocityFunctor(*latDat);
-	size_t const N(dom->GetMidDomainCollisionCount(0));
+    auto [begin, end] = dom->GetMidDomainSiteRange(0);
+    auto const N = end - begin;
 
 	REQUIRE(N > 0);
 
-	for (size_t index(0); index < N; ++index) {
+	for (auto index = begin; index < end; ++index) {
 	  geometry::Site<geometry::FieldData const> const site(index, *latDat);
 
 	  // Value to test
@@ -352,9 +353,9 @@ namespace hemelb::tests
 	velocityFromLatticeDataTester(kernel, false);
       }
       SECTION("VelocityDataFromLatticeWithForces") {
-	size_t const N = dom->GetMidDomainCollisionCount(0);
+            auto [begin, end] = dom->GetMidDomainSiteRange(0);
 
-	for (size_t i = 0; i < N; ++i)
+	for (size_t i = begin; i < end; ++i)
 	  latDat->GetSite(i).SetForce(LatticeForceVector(i, 2 * i, double(i * i) * 0.0001));
 
 	GuoForcingLBGK kernel{initParams};
diff --git a/Code/tests/redblood/LoadDeformedCellTests.cc b/Code/tests/redblood/LoadDeformedCellTests.cc
index 68a8bf63e..c7c7d0649 100644
--- a/Code/tests/redblood/LoadDeformedCellTests.cc
+++ b/Code/tests/redblood/LoadDeformedCellTests.cc
@@ -8,7 +8,7 @@
 #include <catch2/catch.hpp>
 #include <boost/uuid/uuid_io.hpp>
 
-#include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "lb/lattices/D3Q19.h"
 #include "Traits.h"
 #include "redblood/Mesh.h"
@@ -25,7 +25,6 @@ namespace hemelb::tests
 
       using Traits = Traits<lb::D3Q19, lb::GuoForcingLBGK>;
       using CellControl = hemelb::redblood::CellController<Traits>;
-      using MasterSim = SimulationMaster<Traits>;
 
       redblood::VTKMeshIO io = {};
 
@@ -54,7 +53,7 @@ namespace hemelb::tests
         "hemelb", "-in", "large_cylinder_rbc.xml",
       };
       auto options = std::make_shared<configuration::CommandLine>(argc, argv);
-      auto master = std::make_shared<MasterSim>(*options, Comms());
+      auto master = configuration::SimBuilder::CreateSim<Traits>(*options, Comms());
 
       SECTION("testIntegration") {
         // Read meshes from disc
diff --git a/Code/tests/redblood/MulticellBenchmarkTests.cc b/Code/tests/redblood/MulticellBenchmarkTests.cc
index 5698c8d22..b2f3b3ded 100644
--- a/Code/tests/redblood/MulticellBenchmarkTests.cc
+++ b/Code/tests/redblood/MulticellBenchmarkTests.cc
@@ -7,7 +7,7 @@
 #include <boost/uuid/uuid_io.hpp>
 #include <catch2/catch.hpp>
 
-#include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "Traits.h"
 #include "redblood/Mesh.h"
 #include "redblood/MeshIO.h"
@@ -26,9 +26,8 @@ namespace hemelb::tests
     {
         using MyTraits = Traits<lb::DefaultLattice, lb::GuoForcingLBGK>;
         using CellControl = hemelb::redblood::CellController<MyTraits>;
-        using MasterSim = SimulationMaster<MyTraits>;
 
-        std::shared_ptr<MasterSim> master;
+        std::unique_ptr<SimulationMaster> master;
 
         static constexpr auto argv = std::array{"hemelb", "-in", "large_cylinder_rbc.xml"};
         configuration::CommandLine options = {argv.size(), argv.data()};
@@ -69,14 +68,14 @@ namespace hemelb::tests
                                                        "value" },
                            3e-6);
 
-            master = std::make_shared<MasterSim>(options, Comms());
+            master = configuration::SimBuilder::CreateSim<MyTraits>(options, Comms());
         }
 
         void testBenchmark()
         {
             unsigned timestep = 0;
             auto output_callback =
-                    [this, &timestep](const hemelb::redblood::CellContainer & cells) {
+                    [this, &timestep](const redblood::CellContainer & cells) {
                         if ((timestep % 100) == 0) {
                             for (auto& cell: cells) {
                                 std::stringstream filename;
diff --git a/Code/tests/redblood/NodeIntegrationTests.cc b/Code/tests/redblood/NodeIntegrationTests.cc
index 6057e3e20..55e107f14 100644
--- a/Code/tests/redblood/NodeIntegrationTests.cc
+++ b/Code/tests/redblood/NodeIntegrationTests.cc
@@ -9,7 +9,7 @@
 #include <catch2/catch.hpp>
 
 #include "Traits.h"
-#include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "redblood/Cell.h"
 #include "redblood/CellController.h"
 #include "tests/redblood/Fixtures.h"
@@ -41,7 +41,7 @@ namespace hemelb::tests
         }
 
         //! Creates a simulation. Does not run it.
-        std::shared_ptr<SimulationMaster<TRAITS>> simulationMaster(size_t steps,
+        auto simulationMaster(size_t steps,
                                                                    Dimensionless cell,
                                                                    Dimensionless wall) const {
             CopyResourceToTempdir(xml_name);
@@ -60,7 +60,7 @@ namespace hemelb::tests
             ModifyXMLInput(xml_name, { "redbloodcells", "cell2Wall", "intensity", "value" }, wall);
             ModifyXMLInput(xml_name, { "redbloodcells", "cell2Wall", "cutoffdistance", "value" }, 1);
             auto options = std::make_shared<configuration::CommandLine>(argc, argv);
-            auto const master = std::make_shared<SimulationMaster<TRAITS>>(*options, Comms());
+            auto master = configuration::SimBuilder::CreateSim<TRAITS>(*options, Comms());
             helpers::LatticeDataAccess(&master->GetFieldData()).ZeroOutForces();
             return master;
         }
diff --git a/Code/tests/redblood/SadCellIntegrationTests.cc b/Code/tests/redblood/SadCellIntegrationTests.cc
index 19c0c1e90..4dd800011 100644
--- a/Code/tests/redblood/SadCellIntegrationTests.cc
+++ b/Code/tests/redblood/SadCellIntegrationTests.cc
@@ -8,6 +8,7 @@
 #include <catch2/catch.hpp>
 
 #include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 #include "lb/lattices/D3Q19.h"
 #include "Traits.h"
 #include "redblood/Mesh.h"
@@ -22,12 +23,11 @@ namespace hemelb::tests
 
     TEST_CASE_METHOD(helpers::FolderTestFixture,
 		     "SadCellIntegrationTests", "[redblood][.long]") {
-      using Traits = Traits<lb::D3Q19, hemelb::lb::GuoForcingLBGK>;
-      using CellControl = hemelb::redblood::CellController<Traits>;
-      using MasterSim = SimulationMaster<Traits>;
+      using Traits = Traits<lb::D3Q19, lb::GuoForcingLBGK>;
+      using CellControl = CellController<Traits>;
 
-      redblood::KruegerMeshIO msh_io = {};
-      redblood::VTKMeshIO vtk_io = {};
+      KruegerMeshIO msh_io = {};
+      VTKMeshIO vtk_io = {};
 
       CopyResourceToTempdir("large_cylinder_rbc.xml");
       CopyResourceToTempdir("large_cylinder.gmy");
@@ -56,9 +56,9 @@ namespace hemelb::tests
 	"-in",
 	"large_cylinder_rbc.xml",
       };
-      hemelb::configuration::CommandLine options(argc, argv);
+      configuration::CommandLine options(argc, argv);
 
-      auto master = std::make_shared<MasterSim>(options, Comms());
+      auto master = configuration::SimBuilder::CreateSim<Traits>(options, Comms());
 
       SECTION("integration test") {
 	auto const normal = msh_io.readFile(resources::Resource("rbc_ico_1280.msh").Path(), true);
diff --git a/Code/tests/redblood/parallel/GraphCommsTests.cc b/Code/tests/redblood/parallel/GraphCommsTests.cc
index bb3db45f8..3f0b05867 100644
--- a/Code/tests/redblood/parallel/GraphCommsTests.cc
+++ b/Code/tests/redblood/parallel/GraphCommsTests.cc
@@ -3,7 +3,6 @@
 // file AUTHORS. This software is provided under the terms of the
 // license in the file LICENSE.
 
-#include "tests/helpers/FolderTestFixture.h"
 #include "tests/redblood/Fixtures.h"
 #include "tests/redblood/parallel/ParallelFixtures.h"
 #include "lb/iolets/InOutLet.h"
@@ -12,7 +11,7 @@ namespace hemelb::tests
 {
     using namespace redblood;
 
-    class GraphCommsTests : public helpers::FolderTestFixture
+    class GraphCommsTests : public OpenSimFixture
     {
     public:
         GraphCommsTests();
@@ -24,28 +23,28 @@ namespace hemelb::tests
         void testComputeGlobalCoordsToProcMap();
 
     protected:
-        std::shared_ptr<configuration::CommandLine> options;
-
-        //! Meta-function to create simulation type
-        template<class STENCIL>
-        using MasterSim = OpenedSimulationMaster<
-                Traits<
-                        lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
-                        lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
-                        STENCIL
-                >
-        >;
-
-        //! Creates a master simulation
-        template<class STENCIL = stencil::FourPoint>
-        [[nodiscard]] auto CreateMasterSim(net::IOCommunicator const &comm) const
-        {
-            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
-        }
+//        std::shared_ptr<configuration::CommandLine> options;
+//
+//        //! Meta-function to create simulation type
+//        template<class STENCIL>
+//        using MasterSim = OpenedSimulationMaster<
+//                Traits<
+//                        lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
+//                        lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
+//                        STENCIL
+//                >
+//        >;
+//
+//        //! Creates a master simulation
+//        template<class STENCIL = stencil::FourPoint>
+//        [[nodiscard]] auto CreateMasterSim(net::IOCommunicator const &comm) const
+//        {
+//            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
+//        }
 
     };
 
-    GraphCommsTests::GraphCommsTests() : FolderTestFixture() {
+    GraphCommsTests::GraphCommsTests() : OpenSimFixture() {
       // Have everything ready to creates simulations
       if (Comms().Rank() == 0) {
 	CopyResourceToTempdir("large_cylinder_rbc.xml");
@@ -127,7 +126,7 @@ namespace hemelb::tests
         REQUIRE(4 == comms.Size());
 
         // Setup simulation with cylinder
-        auto master = CreateMasterSim(comms);
+        auto master = CreateMasterSim<stencil::FourPoint>(comms);
         REQUIRE(master);
         auto &latticeData = master->GetFieldData();
 
@@ -158,7 +157,7 @@ namespace hemelb::tests
 
         // Setup simulation with cylinder
         auto comms = Comms();
-        auto master = CreateMasterSim(comms);
+        auto master = CreateMasterSim<stencil::FourPoint>(comms);
         REQUIRE(master);
 
         auto simConf = master->GetSimConfig();
@@ -198,7 +197,7 @@ namespace hemelb::tests
         REQUIRE(4 == comms.Size());
 
         // Setup simulation with cylinder
-        auto master = CreateMasterSim(comms);
+        auto master = CreateMasterSim<stencil::FourPoint>(comms);
         REQUIRE(master);
         auto &domain = master->GetFieldData().GetDomain();
         auto graphComm = comms.DistGraphAdjacent(
diff --git a/Code/tests/redblood/parallel/MPIIntegrateVelocities.cc b/Code/tests/redblood/parallel/MPIIntegrateVelocities.cc
index 4e20e819e..2ef9ffffb 100644
--- a/Code/tests/redblood/parallel/MPIIntegrateVelocities.cc
+++ b/Code/tests/redblood/parallel/MPIIntegrateVelocities.cc
@@ -24,7 +24,7 @@ namespace hemelb::tests
 {
     using namespace redblood;
 
-    class MPIIntegrateVelocitiesTests : public helpers::FolderTestFixture
+    class MPIIntegrateVelocitiesTests : public OpenSimFixture
     {
     public:
         MPIIntegrateVelocitiesTests();
@@ -46,30 +46,11 @@ namespace hemelb::tests
         }
 
     protected:
-        std::shared_ptr<configuration::CommandLine> options;
-
-        //! Meta-function to create simulation type
-        template<class STENCIL>
-        using MasterSim = OpenedSimulationMaster<
-                Traits<
-                        lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
-                        lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
-                        STENCIL
-                >
-        >;
-
-        //! Creates a master simulation
-        template<class STENCIL>
-        auto CreateMasterSim(net::IOCommunicator const &comm) const
-        {
-            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
-        }
-
         template<class STENCIL>
         void Check(size_t mid, size_t edges, size_t nCells);
     };
 
-    MPIIntegrateVelocitiesTests::MPIIntegrateVelocitiesTests() : FolderTestFixture()
+    MPIIntegrateVelocitiesTests::MPIIntegrateVelocitiesTests() : OpenSimFixture()
     {
       using hemelb::configuration::CommandLine;
 
@@ -99,7 +80,7 @@ namespace hemelb::tests
     {
       using hemelb::redblood::CellContainer;
       using hemelb::redblood::TemplateCellContainer;
-      using Traits = typename MasterSim<STENCIL>::Traits;
+      using Traits = MyTraits<STENCIL>;
 
       auto const world = net::MpiCommunicator::World();
       auto const color = world.Rank() == 0;
diff --git a/Code/tests/redblood/parallel/MPILockStepTests.cc b/Code/tests/redblood/parallel/MPILockStepTests.cc
index d56f85458..a9183ce7e 100644
--- a/Code/tests/redblood/parallel/MPILockStepTests.cc
+++ b/Code/tests/redblood/parallel/MPILockStepTests.cc
@@ -24,7 +24,7 @@ namespace hemelb::tests
 {
     using namespace redblood;
     //! Parallel and Sequential move in lock step
-    class MPILockStepTests : public helpers::FolderTestFixture
+    class MPILockStepTests : public OpenSimFixture
     {
     public:
         MPILockStepTests();
@@ -35,28 +35,12 @@ namespace hemelb::tests
         }
 
     protected:
-        std::shared_ptr<configuration::CommandLine> options;
-
-        //! Meta-function to create simulation type
-        template<class STENCIL>
-        using MasterSim = OpenedSimulationMaster<Traits<
-                lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
-                lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
-                STENCIL
-        >>;
-
-        //! Creates a master simulation
-        template<class STENCIL>
-        [[nodiscard]] auto CreateMasterSim(net::IOCommunicator const &comm) const
-        {
-            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
-        }
 
         template<class STENCIL> void Check();
     };
 
 
-    MPILockStepTests::MPILockStepTests(): FolderTestFixture() {
+    MPILockStepTests::MPILockStepTests(): OpenSimFixture() {
       // Have everything ready to creates simulations
       if (Comms().Rank() == 0) {
 	CopyResourceToTempdir("cyl_l100_r5.xml");
@@ -144,7 +128,7 @@ namespace hemelb::tests
     template<class STENCIL>
     void MPILockStepTests::Check()
     {
-        using Traits = typename MasterSim<STENCIL>::Traits;
+        using Traits = MyTraits<STENCIL>;
 
         auto const world = Comms();
         auto const color = world.Rank() == 0;
diff --git a/Code/tests/redblood/parallel/MPIParallelIntegrationTests.cc b/Code/tests/redblood/parallel/MPIParallelIntegrationTests.cc
index b406317cd..15306464d 100644
--- a/Code/tests/redblood/parallel/MPIParallelIntegrationTests.cc
+++ b/Code/tests/redblood/parallel/MPIParallelIntegrationTests.cc
@@ -22,7 +22,7 @@ namespace hemelb::tests
 {
     using namespace redblood;
 
-    class MPIParallelIntegrationTests : public helpers::FolderTestFixture
+    class MPIParallelIntegrationTests : public OpenSimFixture
     {
     public:
         MPIParallelIntegrationTests();
@@ -33,29 +33,10 @@ namespace hemelb::tests
         }
 
     protected:
-        std::shared_ptr<hemelb::configuration::CommandLine> options;
-
-        //! Meta-function to create simulation type
-        template<class STENCIL>
-        using MasterSim = OpenedSimulationMaster<
-                Traits<
-                        lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
-                        lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
-                        STENCIL
-                >
-        >;
-
-        //! Creates a master simulation
-        template<class STENCIL>
-        [[nodiscard]] auto CreateMasterSim(net::IOCommunicator const &comm) const
-        {
-            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
-        }
-
         template<class STENCIL> void Check();
     };
 
-    MPIParallelIntegrationTests::MPIParallelIntegrationTests() : FolderTestFixture()
+    MPIParallelIntegrationTests::MPIParallelIntegrationTests() : OpenSimFixture()
     {
       // Have everything ready to creates simulations
       if (net::MpiCommunicator::World().Rank() == 0) {
@@ -91,7 +72,7 @@ namespace hemelb::tests
     void MPIParallelIntegrationTests::Check() {
       using hemelb::redblood::CellContainer;
       using hemelb::redblood::TemplateCellContainer;
-      using Traits = typename MasterSim<STENCIL>::Traits;
+      using T = MyTraits<STENCIL>;
 
       auto const world = net::MpiCommunicator::World();
       auto const color = world.Rank() == 0;
@@ -101,11 +82,11 @@ namespace hemelb::tests
       REQUIRE(master);
 
       unsigned num_cells;
-      auto checkNumCells = [&num_cells]( const hemelb::redblood::CellContainer & cells) {
+      auto checkNumCells = [&num_cells]( const CellContainer & cells) {
 	num_cells = cells.size();
       };
 
-      auto controller = std::static_pointer_cast<hemelb::redblood::CellController<Traits>>(master->GetCellController());
+      auto controller = std::static_pointer_cast<CellController<T>>(master->GetCellController());
       REQUIRE(controller);
       controller->AddCellChangeListener(checkNumCells);
 
diff --git a/Code/tests/redblood/parallel/MPISpreadForcesTests.cc b/Code/tests/redblood/parallel/MPISpreadForcesTests.cc
index 8c0a4c3bd..8b307725e 100644
--- a/Code/tests/redblood/parallel/MPISpreadForcesTests.cc
+++ b/Code/tests/redblood/parallel/MPISpreadForcesTests.cc
@@ -21,7 +21,7 @@
 
 namespace hemelb::tests
 {
-    class MPISpreadForcesTests : public helpers::FolderTestFixture
+    class MPISpreadForcesTests : public OpenSimFixture
     {
     public:
         MPISpreadForcesTests();
@@ -40,29 +40,10 @@ namespace hemelb::tests
         }
 
     protected:
-        std::shared_ptr<hemelb::configuration::CommandLine> options;
-
-        //! Meta-function to create simulation type
-        template<class STENCIL>
-        using MasterSim = OpenedSimulationMaster<
-                Traits<
-                        lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
-                        lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
-                        STENCIL
-                >
-        >;
-
-        //! Creates a master simulation
-        template<class STENCIL>
-        auto CreateMasterSim(net::IOCommunicator const &comm) const
-        {
-            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
-        }
-
         template<class STENCIL> void Check(size_t mid, size_t edges, size_t nCells);
     };
 
-    MPISpreadForcesTests::MPISpreadForcesTests() : FolderTestFixture::FolderTestFixture()
+    MPISpreadForcesTests::MPISpreadForcesTests() : OpenSimFixture()
     {
       using hemelb::configuration::CommandLine;
 
@@ -117,8 +98,8 @@ namespace hemelb::tests
       mpi_spreader.PostMessageLength(distributions, owned);
       mpi_spreader.ComputeForces(owned);
       mpi_spreader.PostForcesAndNodes(distributions, owned);
-      mpi_spreader.SpreadLocalForces<typename MasterSim<STENCIL>::Traits>(fieldData, owned);
-      mpi_spreader.SpreadNonLocalForces<typename MasterSim<STENCIL>::Traits>(fieldData);
+      mpi_spreader.SpreadLocalForces<MyTraits<STENCIL>>(fieldData, owned);
+      mpi_spreader.SpreadNonLocalForces<MyTraits<STENCIL>>(fieldData);
 
       std::vector<LatticeVector> indices;
       std::vector<LatticeForceVector> forces;
diff --git a/Code/tests/redblood/parallel/ParallelFixtureTests.cc b/Code/tests/redblood/parallel/ParallelFixtureTests.cc
index ac11f1f94..71b706f3b 100644
--- a/Code/tests/redblood/parallel/ParallelFixtureTests.cc
+++ b/Code/tests/redblood/parallel/ParallelFixtureTests.cc
@@ -11,6 +11,7 @@
 #include "util/span.h"
 #include "redblood/parallel/NodeCharacterizer.h"
 #include "configuration/CommandLine.h"
+#include "configuration/SimBuilder.h"
 #include "tests/redblood/Fixtures.h"
 #include "tests/helpers/LatticeDataAccess.h"
 #include "tests/helpers/FolderTestFixture.h"
@@ -20,36 +21,17 @@ namespace hemelb::tests
 {
     using namespace redblood;
     //! Parallel and Sequential move in lock step
-    class ParallelFixtureTests : public helpers::FolderTestFixture
+    class ParallelFixtureTests : public OpenSimFixture
     {
     public:
         ParallelFixtureTests();
 
         //! if owner procs thinks position affects proc i, then proc i knows it as well
         void testTransitiveOwnership();
-    protected:
-        std::shared_ptr<configuration::CommandLine> options;
-
-        //! Meta-function to create simulation type
-        template<class STENCIL>
-        using MasterSim = OpenedSimulationMaster<
-                Traits<
-                        lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
-                        lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
-                        STENCIL
-                >
-        >;
-
-        //! Creates a master simulation
-        template<class STENCIL>
-        auto CreateMasterSim(net::IOCommunicator const &comm) const
-        {
-            return std::make_shared<MasterSim<STENCIL>>(*options, comm);
-        }
     };
 
 
-    ParallelFixtureTests::ParallelFixtureTests() : FolderTestFixture()
+    ParallelFixtureTests::ParallelFixtureTests() : OpenSimFixture()
     {
       // Have everything ready to create simulations
       if (Comms().Rank() == 0)
diff --git a/Code/tests/redblood/parallel/ParallelFixtures.cc b/Code/tests/redblood/parallel/ParallelFixtures.cc
index b9c3d787d..c223d8347 100644
--- a/Code/tests/redblood/parallel/ParallelFixtures.cc
+++ b/Code/tests/redblood/parallel/ParallelFixtures.cc
@@ -19,8 +19,8 @@ namespace hemelb::tests
       std::random_device rd;
       std::mt19937 g(rd());
 
-      int const nMids = domain.GetMidDomainCollisionCount(0);
-      int const nEdges = domain.GetDomainEdgeCollisionCount(0);
+      int const nMids = domain.GetMidDomainSiteCount(0);
+      int const nEdges = domain.GetDomainEdgeSiteCount(0);
       std::vector<LatticeVector> positions(c.Size() * (mid + edges));
       std::vector<int> shuf(nMids);
       std::iota(shuf.begin(), shuf.end(), 0);
diff --git a/Code/tests/redblood/parallel/ParallelFixtures.h b/Code/tests/redblood/parallel/ParallelFixtures.h
index eef9d5d4a..b7587c151 100644
--- a/Code/tests/redblood/parallel/ParallelFixtures.h
+++ b/Code/tests/redblood/parallel/ParallelFixtures.h
@@ -8,7 +8,9 @@
 
 #include "redblood/Cell.h"
 #include "tests/redblood/Fixtures.h"
+#include "tests/helpers/FolderTestFixture.h"
 #include "SimulationMaster.h"
+#include "configuration/SimBuilder.h"
 
 namespace hemelb::tests
 {
@@ -20,16 +22,17 @@ namespace hemelb::tests
 						      net::MpiCommunicator const &c);
 
     //! Make some functionality available
-    template<class TRAITS>
-    class OpenedSimulationMaster : public SimulationMaster<TRAITS>
+    class OpenedSimulationMaster : public SimulationMaster
     {
     public:
-        using SimulationMaster<TRAITS>::SimulationMaster;
-        using SimulationMaster<TRAITS>::Finalise;
+        //using SimulationMaster::SimulationMaster;
+        using SimulationMaster::Finalise;
+        OpenedSimulationMaster(SimulationMaster&& src) : SimulationMaster(src) {
+        }
 
         void DoTimeStep()
         {
-            SimulationMaster<TRAITS>::DoTimeStep();
+            SimulationMaster::DoTimeStep();
         }
 
         configuration::SimConfig const& GetSimConfig()
@@ -38,6 +41,26 @@ namespace hemelb::tests
         }
     };
 
+    class OpenSimFixture : public helpers::FolderTestFixture {
+    protected:
+        template <typename STENCIL>
+        using MyTraits = Traits<
+                lb::DefaultLattice, lb::GuoForcingLBGK, lb::Normal,
+                lb::DefaultStreamer, lb::DefaultWallStreamer, lb::DefaultInletStreamer, lb::DefaultOutletStreamer,
+                STENCIL
+        >;
+
+        std::shared_ptr<configuration::CommandLine> options;
+        template<class STENCIL>
+        [[nodiscard]] auto CreateMasterSim(net::IOCommunicator const &comm) const {
+            using T = MyTraits<STENCIL>;
+            auto tmp =  configuration::SimBuilder::CreateSim<T>(
+                    *options, comm
+            );
+            return std::unique_ptr<OpenedSimulationMaster>(new OpenedSimulationMaster(std::move(*tmp)));
+        }
+    };
+
     class DummyCell : public NodeCell {
     public:
       LatticeForce force;