Eight people were killed when a house collapsed at the Meyersdal Eco Estate in Alberton, south-east of Johannesburg, on Monday, paramedics said.
Two of the 27 builders working on the house were still missing under the rubble, ER24 spokeswoman Luyanda Majija said.
Six people were injured and taken to hospital.
Earlier, Netcare 911 said five people had been killed and eight injured. Nine people were then believed to still be stuck under the rubble.
Ekurhuleni emergency services said the toll had risen to eight.
"As we [were] busy searching we discovered another three bodies," spokesman William Ntladi said.
"The total is eight for now, but the search is still going on. This number might change," he said.
Security at the upmarket estate was tight as non-residents were questioned before they were allowed access. Some were turned away.
The estate confirmed the building collapse.
"Today, at approximately 10.30am, a structure at the house of one of our residents which was undergoing alterations collapsed," it said in a statement.
"Emergency services are still involved in rescue operations and the families of the affected workers have yet to be informed."
The Meyersdal Eco Estate is the property from where two giraffes were removed last month.
The giraffes were being transported on the N1 highway on a truck when one of them hit its head on a bridge and died.
Last week, the Gauteng agriculture department said the estate was being investigated over whether it had the correct permits to bring in and keep giraffes.