An awning has been put up at the foot of the Housing Board block where President Halimah Yacob lives, one of various changes to the estate since her inauguration on Thursday.
The white awning extends from the void deck of the Yishun HDB block and covers a carpark space reserved for police vehicles.
The official car of the President has been seen parked in that space.
Police have intensified security measures in the area.
Asked about the latest developments, the police yesterday declined comment, saying these were "security and operational matters".
Madam Halimah is Singapore's eighth President. The 63-year-old has lived in her jumbo Yishun flat - comprised of a four-room and five-room flat - with her family for more than 30 years.
She has told reporters she intends to continue living there while in office.