diff --git a/zorg/buildbot/process/buildrequest.py b/zorg/buildbot/process/buildrequest.py
new file mode 100644
index 0000000..7af49a1
--- /dev/null
+++ b/zorg/buildbot/process/buildrequest.py
@@ -0,0 +1,69 @@
+from twisted.internet import defer
+
+@defer.inlineCallbacks
+def collapseRequests(master, builder, req1, req2):
+    """
+    Returns true if both buildrequest can be merged, via Deferred.
+
+    This implements Zorg's default collapse strategy.
+    """
+     # If these are for the same buildset, collapse away
+    if req1['buildsetid'] == req2['buildsetid']:
+        return True
+
+    # Get the buidlsets for each buildrequest
+    selfBuildsets = yield master.data.get(
+        ('buildsets', str(req1['buildsetid'])))
+    otherBuildsets = yield master.data.get(
+        ('buildsets', str(req2['buildsetid'])))
+
+    # extract sourcestamps, as dictionaries by codebase
+    selfSources = dict((ss['codebase'], ss)
+                        for ss in selfBuildsets['sourcestamps'])
+    otherSources = dict((ss['codebase'], ss)
+                        for ss in otherBuildsets['sourcestamps'])
+
+    # if the sets of codebases do not match, we can't collapse
+    if set(selfSources) != set(otherSources):
+        return False
+
+    for c, selfSS in selfSources.items():
+        otherSS = otherSources[c]
+        if selfSS['repository'] != otherSS['repository']:
+            return False
+
+        if selfSS['branch'] != otherSS['branch']:
+            return False
+
+        # TODO: Handle projects matching if we ever would have
+        # a mix of projects from the monorepo and outside of
+        # the monorepo. For now, we consider all of them being
+        # a part of the monorepo, so all of them are compatible
+        # and could be collapsed.
+
+        # anything with a patch won't be collapsed
+        if selfSS['patch'] or otherSS['patch']:
+            return False
+
+        # get changes & compare
+        selfChanges = yield master.data.get(('sourcestamps', selfSS['ssid'], 'changes'))
+        otherChanges = yield master.data.get(('sourcestamps', otherSS['ssid'], 'changes'))
+        # if both have changes, proceed, else fail - if no changes check revision instead
+        if selfChanges and otherChanges:
+            continue
+
+        if selfChanges and not otherChanges:
+            return False
+
+        if not selfChanges and otherChanges:
+            return False
+
+        # else check revisions
+        if selfSS['revision'] != otherSS['revision']:
+            return False
+
+    # Build requests with different reasons should be built separately.
+    if req1.get('reason', None) == req2.get('reason', None):
+        return True
+    else:
+        return False