As the building was virtually flattened, they thought it would be impossible to reunite the cubs with their mum and so called East Sussex WRAS rescuer Trevor Weeks.
The cubs were initially taken to two local veterinary centres and then to the Cats Protection League before being taken to East Sussex WRAS for identification as fox cubs.
Another tiny cub was found in Seaford just last week, but Trevor said these foxes are even smaller.
He said, 'Thanks to the workmen, these cubs are alive.
'They could easily have been missed and been killed.'
New WRAS rescuers David and Shirley Clark from Pevensey Bay collected the cubs from the Cats Protection League shelter in Hailsham before transporting them to Trevor at Uckfield.
Trevor said, 'I gave them a feed as soon as they arrived using a special milk replacement, as ordinary milk is bad for them.
'They are amazingly cute. I don't know how anyone could harm such a beautiful creature.'
All three cubs have now been taken to the Fox Project for their expert attention because they are so small and young.