When DH was building a storage shed in the backyard a few years ago, my dad happened to call on the phone. When I told him what we were all up to that day and he found out what DH was doing, his comment rings in my head. "No matter what size he thinks he needs, double it!" I think it applies for this too. By the way, he was right about the storage shed, it only took putting things in to realize, it should have been bigger. Double would have worked.