What size house can be built on an 0.33 acre lot with yard?

Well, honey, on a 0.33 acre lot, you could build a house ranging from around 1,200 to 1,800 square feet, depending on local zoning regulations and setbacks. Just make sure to leave some space for that yard you're so concerned about, unless you want your house to be the main attraction in a postage stamp-sized lawn. Happy building!