Los Angeles’ long-awaited Academy Museum of Motion Pictures has taken a big step forward this week, after media mogul Haim Saban donated US$50m (€42.4m, £37.2m) towards the US$388m (€329.2m, £288.7m) project.

The donation from Haim and his wife Cheryl brings the museum’s fundraising total to US$288m (€244.3m, £214.3m) leaving it US$100m (€84.9m, £74.4m) short of its total. In recognition of the gift, the five-storey structure which will house the museum’s exhibits will be renamed the Saban Building.

From its conception, the museum has struggled to meet financial targets, with this the first contribution since the departure of the museum’s chief fundraiser Bill Kramer, who left the project in October 2015. Katharine DeShaw was named as his replacement in October 2016.

“We are deeply grateful to Cheryl and Haim for understanding the need for a superb museum of film in the moviemaking capital of the world,” said Disney chair Bob Iger, who is also chair of the Museum Campaign Committee.

“With their tremendous commitment, they set a magnificent example for others and bring our dream closer to reality.”

Saban’s donation comes with the release of new renderings by project architect Renzo Piano, showing for the first time spaces within the museum, which will look at the evolution of film, utilising large-scale screens, costumes, props, sound installations, and other artefacts. Separate from the core exhibition, the third floor also features an Oscars experience, using innovative technology to place visitors on Hollywood’s most prestigious red carpet and stage and give them the rare chance to hold a real Oscar as they accept their award.

Originally slated to open this year, lengthy delays and skyrocketing costs have meant the project hasn’t been able to follow the Hollywood script, having been been pushed back several times.

The museum, which broke ground in March last year, was originally budgeted at US$250m (€212m, £186m) when it was first conceived several years ago, but since then costs have swollen to the existing US$388m sum.

Piano’s design is split into two parts – the newly-named Saban Building and a 130-foot glass sphere featuring a theatre and terrace.

Both buildings sit on the museums 300,000sq ft (27,900sq m) campus, which will feature 50,000sq ft (4,650sq m) of gallery space, two theatres, project spaces, an outdoor piazza, the rooftop terrace, an active education studio, a restaurant, and a retail unit.

Film production designer Rick Carter, a two-time Academy Award winner, and London-based firm Gainsbury and Whiting will be handling design for the core exhibition.

“People from across the globe come to Los Angeles to be inspired, and to see things they have only imagined become real through storytelling,” said city mayor Eric Garcetti.

“It’s only fitting that the filmmaking capital of the world will soon have a space dedicated to its industry and artistry. The Academy Museum of Motion Pictures will add another world-class institution to our city’s cultural landscape, and touch the lives of Angelenos and visitors for generations to come.”

When open, The Academy predicts a total of 860,000 visitors to the museum on an annual basis, with 150 permanent jobs created. A tentative opening date is now set for April 2019.