A major design flaw has been revealed for the new museum for western Sydney – it has no entry for visitors.

Powerhouse Museum chief executive Lisa Havilah was quizzed about the $1.5 billion building at Senate Estimates yesterday, Nine News reports.

The museum has to be elevated because it will sit on a flood plain in Parramatta and one option is to put it on stilts.

But such a plan hasn’t allowed for a way to get into the museum, which is being relocated from its site in Ultimo.

Ms Havilah was asked if there would be stairs or an escalator for people to get up to the building.

“Well that’s a process that’s being worked through… as part of the stage three design,” she said.