Following a two-year fundraising campaign, the San Francisco Museum of Modern Art (MOMA) is closing in on its financial target to build a 235,000sq ft (21,800sq m) new wing.

The US$610m (€513m, £401m) figure would fund the new wing – which would house works by the likes of Andy Warhol, Mark Rothko and David Hockney – and secure the future of the museum for many years to come.

The expanded building, which will cost an estimated US$305m (€256, £201m) and has been designed by Snøhetta architecture, will include seven levels dedicated to art and public programming. The under-construction wing will open in 2016, more than doubling the existing space and cementing MOMA's position as a cultural hub for San Francisco.

The designs for the expanded building include new features such as a large-scale vertical garden; a ground-floor gallery with 25ft-high (7.6m) glass walls that will place art on view to passers-by; a double-height "white box" space with lighting and sound systems; and state-of-the-art conservation studios. The building has also been designed to achieve LEED Gold certification, with 15 per cent energy-cost reduction, 30 per cent water-use reduction, and a 20 per cent reduction in wastewater generation.

During the two-and-a-half year expansion process, MOMA has been temporarily closed. During this period, MOMA is presenting exhibitions and public programmes at partner museums and other venues throughout the San Francisco Bay Area. Once the new wing launches in early 2016, the museum expects attendance to jump from the current 650,000 a year to more than one million visitors annually.