As a structurally sound material, redwood is ideal for both indoor and outdoor projects. Less prone to shrinkage or swelling than other woods, redwood lumber lasts 25 to 35 years with minimal maintenance, and over 100 years when used inside. Redwood is resistant to insects, fire, and rot, adding durability to structures that need to brave the elements. In the summer months, it stays cool enough for bare feet.  Photo 3 of 7 in Beauty and Brains: Building Sustainably With Redwood