Abe Kruger honed his expertise in sustainable construction over the last 20 years as a contractor, educator, and consultant in the residential construction industry. Abe is the cofounder of SK Collaborative, which provides green building, healthy housing, and building enclosure consulting nationwide. SK Collaborative has delivered testing and certification services for more than 58,000 apartments and homes, with nearly 40,000 additional units currently underway. They have completed projects across 20 states, US territories, and countries. He is the coauthor of the first residential green building textbook, Green Building: Principles and Practices in Residential Construction (Delmar/Cengage Learning).