Index: zorg/buildbot/builders/LibcxxAndAbiBuilder.py
===================================================================
--- zorg/buildbot/builders/LibcxxAndAbiBuilder.py
+++ zorg/buildbot/builders/LibcxxAndAbiBuilder.py
@@ -27,10 +27,7 @@
     if depends_on_projects is None:
         depends_on_projects = ['libcxx','libcxxabi','libunwind']
 
-    if build_standalone:
-        src_root = 'runtimes'
-    else:
-        src_root = 'llvm'
+    src_root = 'llvm'
 
     build_path = 'build'
 
@@ -39,6 +36,7 @@
                 depends_on_projects=depends_on_projects,
                 llvm_srcdir=src_root,
                 obj_dir=build_path,
+                build_standalone=build_standalone,
                 **kwargs) # Pass through all the extra arguments.
 
     rel_src_dir = LLVMBuildFactory.pathRelativeTo(f.llvm_srcdir, build_path)
Index: zorg/buildbot/builders/UnifiedTreeBuilder.py
===================================================================
--- zorg/buildbot/builders/UnifiedTreeBuilder.py
+++ zorg/buildbot/builders/UnifiedTreeBuilder.py
@@ -18,6 +18,7 @@
            install_dir = None,
            cleanBuildRequested = None,
            env = None,
+           build_standalone = False,
            **kwargs):
 
     def cleanBuildRequestedByProperty(step):
@@ -33,6 +34,7 @@
             obj_dir=obj_dir,
             install_dir=install_dir,
             cleanBuildRequested=cleanBuildRequested,
+            build_standalone=build_standalone,
             **kwargs) # Pass through all the extra arguments.
 
     # Remove the source code for a clean checkout if requested by property.
@@ -53,6 +55,7 @@
            obj_dir = None,
            install_dir = None,
            cleanBuildRequested = None,
+           build_standalone = False,
            **kwargs):
 
     f = getLLVMBuildFactoryAndPrepareForSourcecodeSteps(
@@ -61,6 +64,7 @@
             obj_dir=obj_dir,
             install_dir=install_dir,
             cleanBuildRequested=cleanBuildRequested,
+            build_standalone=build_standalone,
             **kwargs) # Pass through all the extra arguments.
 
     # Get the source code.
Index: zorg/buildbot/process/factory.py
===================================================================
--- zorg/buildbot/process/factory.py
+++ zorg/buildbot/process/factory.py
@@ -23,6 +23,7 @@
         self.llvm_srcdir = kwargs.pop('llvm_srcdir', None)
         self.obj_dir = kwargs.pop('obj_dir', None)
         self.install_dir = kwargs.pop('install_dir', None)
+        self.build_standalone = kwargs.pop('build_standalone', False)
 
         # Preserve the rest of the given extra attributes if any, so we could
         # expand the factory later.
@@ -30,8 +31,13 @@
             setattr(self, k, v)
 
         self.monorepo_dir = self.llvm_srcdir or "llvm-project"
+        if self.build_standalone:
+            self.build_dir = "runtimes"
+        else:
+            self.build_dir = "llvm"
         self.llvm_srcdir = \
-                "%(monorepo_dir)s/llvm" % {'monorepo_dir' : self.monorepo_dir}
+                "%(monorepo_dir)s/(build_dir)s" % {'monorepo_dir' : self.monorepo_dir,\
+                                                   'build_dir' : self.build_dir}
         self.obj_dir = \
                 self.obj_dir or "build"