The Building Technologies Office (DOE) partners with GSA annually on the Green Proving Ground (GPG/HIT) program for innovative technologies targeted at improving existing buildings. In May of 2021 five technology finalists were chose for field validation. DOE partners with national laboratories for these validations and seek existing commercial building partners as the test sites. 2021's technologies include: advanced nano-fiver air filter, air-born insulation solutions for small air-gaps, retrofit operable window insulation panels, coreless electric motor, and HVAC pretreatment dehumidification. This webinar explained the field validation site expectations, these five technologies in further detail and the site criteria for each technology.