When someone in your household needs to quarantine at home, you want them to be isolated from others as much as possible. Remember that the virus transmits predominantly through the air, so sanitizing surfaces is not enough.
Visit www.healthyheating.com for tips on how to reduce the risk of transmission from one household member to another.
Part I: How to set up an emergency isolation room inside a home or apartment for a suspected infected occupant.
Part II. How to Isolate a Full Basement Renovation from Occupied Upper Floors During a Pandemic
And here is another variation written for readers in India
How to isolate at home if you have COVID-19 while keeping other members safe
See also how to build a high efficiency, low cost DIY air filter, the Corsi-Rosenthal Box.
Related links
NBC News: What to do if a family member tests positive? How to ‘Covid-proof’ your home. The best strategy for avoiding the Covid virus is to make indoor air as much like the outdoors as possible, experts say.
https://www.nbcnews.com/health/health-news/family-member-tests-positive-covid-proof-home-rcna29288