diff --git a/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/control/WorldBuilder.java b/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/control/WorldBuilder.java
index c8b174c2..a854d19f 100644
--- a/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/control/WorldBuilder.java
+++ b/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/control/WorldBuilder.java
@@ -21,6 +21,7 @@
 import codemetropolis.toolchain.rendering.exceptions.TooLongRenderDurationException;
 import codemetropolis.toolchain.rendering.model.building.*;
 import codemetropolis.toolchain.rendering.model.primitive.Boxel;
+import codemetropolis.toolchain.rendering.util.BlockCsvWriterHolder;
 
 public class WorldBuilder {
 
@@ -98,6 +99,9 @@ public void createBlocks(File directory, int maxTime) throws TooLongRenderDurati
 			raiseProgressEvent(BuildPhase.GENERATING_BLOCKS, count, total, timeElapsed);
 		}
 		stopWatch.stop();
+		
+		// Close all PrintWriters after every single block has been written
+		BlockCsvWriterHolder.closeWriters();
 	}
 	
 	public void build(File sourceDirectory) throws RenderingException {
diff --git a/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/model/primitive/Boxel.java b/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/model/primitive/Boxel.java
index 931fff2c..84cb7acd 100644
--- a/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/model/primitive/Boxel.java
+++ b/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/model/primitive/Boxel.java
@@ -1,15 +1,13 @@
 package codemetropolis.toolchain.rendering.model.primitive;
 
-import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileNotFoundException;
-import java.io.FileWriter;
-import java.io.IOException;
 import java.io.PrintWriter;
 
 import codemetropolis.blockmodifier.World;
 import codemetropolis.toolchain.commons.cmxml.Point;
 import codemetropolis.toolchain.rendering.model.BasicBlock;
+import codemetropolis.toolchain.rendering.util.BlockCsvWriterHolder;
 
 public class Boxel implements Primitive {
 	
@@ -71,17 +69,14 @@ public int toCSVFile(File directory) {
 		int x = position.getX() >> 9;
 		int z = position.getZ() >> 9;
 		
-		directory.mkdirs();
 		String filename = String.format("blocks.%d.%d.csv", x, z);
-		File file = new File(directory, filename);
 		
-		try(PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter(file, true)))) {	
+		try {
+		  PrintWriter writer = BlockCsvWriterHolder.requestFile(directory, filename);
 			String csv = toCSV();
 			if(csv != null) writer.println(csv);
 		} catch (FileNotFoundException e) {
 			e.printStackTrace();
-		} catch (IOException e1) {
-			e1.printStackTrace();
 		}
 		return 1;
 	}
diff --git a/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/util/BlockCsvWriterHolder.java b/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/util/BlockCsvWriterHolder.java
new file mode 100644
index 00000000..7c2f9c3e
--- /dev/null
+++ b/sources/codemetropolis-toolchain-rendering/src/main/java/codemetropolis/toolchain/rendering/util/BlockCsvWriterHolder.java
@@ -0,0 +1,66 @@
+package codemetropolis.toolchain.rendering.util;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.PrintWriter;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * This class is used to hold PrintWriter instances for the rendering. Previously, these files were (re-)opened and
+ * closed for every single {@link codemetropolis.toolchain.rendering.model.primitive.Boxel}. Instead of that, it now
+ * holds all of the references for each file, and serves them to the Boxel for writing. When all Boxels have been
+ * written, all these files can be flushed and closed at once.
+ *
+ * @author Adam Bankeszi {@literal <BAAVAGT.SZE>} {@literal <bankeszi.adam@gmail.com>}
+ */
+public class BlockCsvWriterHolder {
+
+  /** Holds the PrintWriter references for the blocks csv files. */
+  private static Map<String, PrintWriter> writers = new HashMap<String, PrintWriter>();
+
+  /**
+   * Requests a {@link PrintWriter} for the given filename. On the first request it attempts to create the file and
+   * stores the associated {@link PrintWriter} reference. When the same file is requested a second time, it simply
+   * returns the already open {@link PrintWriter}.
+   *
+   * @param directory The directory in which these files shall be stored.
+   * @param filename The requested file's name.
+   * @return The {@link PrintWriter} for the requested file.
+   * @throws FileNotFoundException if it fails to create the file (or the parent directory). See
+   *   {@link #createAndStoreWriter(File, String)} for more information.
+   */
+  public static PrintWriter requestFile(File directory, String filename) throws FileNotFoundException {
+    if (writers.containsKey(filename)) {
+      return writers.get(filename);
+    } else {
+      return createAndStoreWriter(directory, filename);
+    }
+  }
+
+  /**
+   * Closes all {@link PrintWriter} instances and clears the storage.
+   */
+  public static void closeWriters() {
+    writers.values().forEach(writer -> writer.close());
+    writers.clear();
+  }
+
+  /**
+   * Creates a new {@link PrintWriter} instance for the specific filename and adds it to the storage.
+   *
+   * @param directory The directory in which the file should be created.
+   * @param filename The filename that should be used.
+   * @return The new {@link PrintWriter} instance for the newly created file.
+   * @throws FileNotFoundException if it fails to create the file (or the parent directory). Its most likely due to
+   *   insufficent user permissions for the given path or insufficent drive space.
+   */
+  private static PrintWriter createAndStoreWriter(File directory, String filename) throws FileNotFoundException {
+    directory.mkdirs();
+    File file = new File(directory, filename);
+    PrintWriter writer = new PrintWriter(file);
+    writers.put(filename, writer);
+    return writer;
+  }
+
+}