From publisher blurb:
Avalon takes a common spell and provides you with a number of alterations and additions to add excitement and useful options for your next adventure. Each issue of Avalon Spell Books will focus on a new spell, discussing different versions of the spell, providing different components that can be used to alter the way the spell works, and even adding feats and new magical items linked to the spell in question.
The classic secure shelter is a convenient way to camp when you have use for eight bunks and a writing desk. Yet it tends to become a mess when you need to accommodate four people, a couple of large mounts or animal companions, plus a water mephit who badly needs a deep pool of water for fast healing.
While certainly many modifications of the basic sturdy cottage can be created, ranging from steamy bathhouses to ogre-sized mess halls, it seems unnecessary to create separate spell for each version. Instead, the basic spell can be modified to replace some of its basic features with more appropriate ones. This approach is detailed in the “variant shelter furnishing” section.