It seems that by default all regions are rendered in Omega theme because of the Debug blocks.
<aside class="grid-3 region region-sidebar-first" id="region-sidebar-first">
<div class="region-inner region-sidebar-first-inner">
<div class="alpha-debug-block"><h2>Sidebar First</h2><p>This is a debugging block</p>
</div>
</div>
</aside>
Is there a way to have an option to debug blocks and hide empty blocks at the same time?