Natural Resources Canada's Office of Energy Efficiency offers this guide to educate on basic principles of building science and to provide guidance in home retrofit projects such as insulation and air sealing improvements. Chapter Summary Section 1: Introduction Section 2: How your house works Section 3: Materials Section 4: Comprehensive air leakage control Section 5: Roofs and attics Section 6: Basement insulation Section 7: Insulating Walls Section 8: Upgrading windows and doors Section 9: Operating your house