What steps should a district take to reopen buildings after a prolonged shutdown or reduced operation? The CDC has recommendations to ensure the safety of occupants and the operation of building systems (HVAC and water), online at https://www.cdc.gov/coronavirus/2019-ncov/php/building-water-system.html.
Is a deep cleaning required upon reopening a school? According to the CDC website (https://www.cdc.gov/coronavirus/2019-ncov/community/reopen-guidance.html), if your workplace, school, or business has been unoccupied for 7 days or more, it will only need your normal routine cleaning to reopen the area. This is because the virus that causes COVID-19 has not been shown to survive on surfaces longer than this time.