The notices were issued on the directions of Noida Chairman Rama Raman, according to an official release of the Authority.
The builders were carrying our the illegal construction in Sarafabad and Sector 72 and 73, it said.
They have been directed to remove the unauthorised construction within a week, failing which the Authority will demolish them and charge an amount from the builders for the demolition, it said.
Notices have been pasted at these sites, according to the release.