This thesis examines existing rehabilitation and environmental guidelines to determine whether the guidelines are incorporating the necessary building science knowledge to ensure that insulation is performing as intended and thus promoting energy efficiency, cost effectiveness, and environmental sustainability. The results of analyzing the existing guidelines show that they do not require all that is necessary to promote energy efficiency and environmental sustainability. While several of the guidelines have started to incorporate the necessary building science perspective by requiring a whole house air leakage test, none of the guidelines examined specifically require the zonal pressure diagnostics test necessary to ensure that insulation is working to specification. The thesis also includes a comprehensive overview of environmental sustainability and rehabilitation.