A full household will have to go into a five-day isolation if anyone in that household is a confirmed case of COVID-19.
Under plans to be announced by Cabinet, they will be sent antigen tests to take at home.
Meanwhile Government advice will to be to work from home after this weekend "where practicable".
A new work from home order will be issued from Friday - but the language accepts that some businesses will not be able to accommodate that.
The Cabinet has also agreed to a roll-out of booster vaccinations to the over-50s, with Taoiseach Micheál Martin telling ministers there will be capacity for 230,000 jabs a week.
There is no timeline on this capacity, but it is expected this side of Christmas.
Nightclubs, bars and restaurants will have to close at midnight from Thursday.
However there will be different arrangements for hotel bars.
Digital COVID Certificates will not be required for access to gyms, barbers and hairdressers.
But they will now be needed for cinemas and theatres - though many were doing this anyway to ensure 100% capacity.
The Cabinet has been meeting to discuss the rising number of cases and worrying warnings from NPHET on the projected admissions to ICU.