At the moment with present perfect

Yesterday I was doing some english exercises and I’ve had some problems with a sentence:

At the moment, most of the work is being done. (solution)

At the moment, most of the work has been done. (my answer)

Why wasn’t mine right? The context says that a lot of work in the house has been done (the walls have been put on, the roof has been put on and the bathroom has been fit), so now it only remains to paint the walls and to fit the kitchen.