diff --git a/_config/blocks.yml b/_config/blocks.yml
index 6fb8460..5211f8f 100644
--- a/_config/blocks.yml
+++ b/_config/blocks.yml
@@ -17,6 +17,6 @@ SiteConfig:
     - BlockSiteConfigExtension
 
 Block:
+  defaultBlockArea: false
   extensions:
     - Versioned('Stage','Live')
-
diff --git a/code/dataobjects/Block.php b/code/dataobjects/Block.php
index 1901965..2f582c7 100644
--- a/code/dataobjects/Block.php
+++ b/code/dataobjects/Block.php
@@ -257,6 +257,16 @@ public function onAfterDuplicate()
         $this->BlockSets()->removeAll();
     }
 
+    public function onBeforeWrite()
+    {
+        $defaultBlockArea = Block::config()->get('defaultBlockArea');
+        $blockArea = $this->getField('ManyMany[BlockArea]');
+        if ($defaultBlockArea !== false && $blockArea === null) {
+            $this->setField('ManyMany[BlockArea]', $defaultBlockArea);
+        }
+        parent::onBeforeWrite();
+    }
+
     /*
      * Base permissions
      */