[2]  BPI’s nationally recognized Building Analyst and Building Envelope credentialing programs identify individual excellence in house-as-a-system evaluation, diagnostics and installation. The Building Analyst trainings consist of building science fundamentals, analysis of diagnostic equipment, assessment of building tightness and practical application of blower door; combustion safety and other diagnostics for assessing air leakage and efficiency in buildings. The Building Envelope training consists of health and safety, indoor air quality assessment, advanced blower door applications, insulation techniques and applications and other topics related to improving building envelope efficiency.