How is that a valid concern? The only way the virus could spread would be through the building door, and maybe elevator buttons. It's a matter of cleaning those regularly and washing your hands when you get home. It's not rocket science.
https://www.cnbc.com/2020/03/18/coronavirus-lives-for-hours-...
E.g. If one sneezes uncovered into air with the right humidity, etc. it COULD survive for a while airborne. That's not to say merely by breathing a person's usual exhalations they could get it.
The virus is transmitted through droplets, or little bits of liquid, mostly through sneezing or coughing, Dr. Maria Van Kerkhove, head of WHO’s emerging diseases and zoonosis unit, told reporters during a virtual news conference on Monday. “When you do an aerosol-generating procedure like in a medical care facility, you have the possibility to what we call aerosolize these particles, which means they can stay in the air a little bit longer.”
https://www.cnbc.com/2020/03/18/coronavirus-lives-for-hours-...
You are aware that the virus spreads primarily through air?