A follow-up to the highly successful XS: Big Ideas, Small Buildings, this book features contemporary solutions to two of today's most challenging problems-how to conserve space and help save the environment. The design goals of the 40 houses included here are to build as small as possible, to harmonize with the site, to use natural heating and cooling techniques, and, above all, to combine aesthetic beauty with ecological sensitivity. The houses are striking in appearance, inexpensive to build, and totally functional, and will serve as inspiration for architects and potential owners.Designed by a variety of young international architects (among them Patkau, ShoP, Sean Godsel, and Klein Dytham) the projects featured here reveal an extraordinary degree of ingenuity within a tight, creative context or budget. As homeowners become more environmentally savvy and demand environmentally sound choices, a new generation of architects and builders is creating warm, inviting homes that cause only a fraction of the ecological impact of conventional building methods. The book is also a compelling manifesto that illustrates how ecological responsibility can reinvigorate contemporary architecture. Sustainability is not just good for the environment-it also propels architects toward new innovations and greater creativity.