Snake catcher Nick Evans rescued his third green mamba from the same construction site in Durban in September.
All three rescues happened in the past year.
The first two mambas were rescued from the same floor of one of the new buildings.
This coastal bush and forest along the KwaZulu-Natal coastline was the green mambas' natural habitat but it was quickly being developed into commercial properties, Evans said.
"Where there used to be trees, now there's a big flat where there home used to be. I think they're a bit confused," he told News24.
Green mambas were listed as a vulnerable species, with habitat destruction being the main threat to their survival, Evans said.
"Green mambas are a special treat. You don't see them often. They stick to themselves in the canopies of trees. They don't generally bother people and a lot of the time people don't even see them."
He added thankfully, the construction crews were "snake friendly" and did not throw rocks at the snakes or tried to hurt them and instead called him for help.
"Green mambas are definitely one of Africa's most beautiful snakes," Evans said.
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