Arriving at the opening of the Victoria & Albert Museum’s new Exhibition Road Quarter the Duchess of Cambridge mouthed “wow”.

The £54.5 million development designed by British architect Amanda Levete comprises the world’s first completely porcelain tiled public courtyard and a column-less underground exhibition space. A History of Art graduate, the Duchess was invited to tour the new spaces on Thursday afternoon (29 June) and unveiled a commemorative plaque to mark their opening.

Originally, the site was destined to house Daniel Libeskind’s “Spiral”, which was commissioned by former V&A Director Alan Borg in 1997. Supported by English Heritage, Kensington and Chelsea Council and the Royal Fine Art Commission it was to become a cultural icon for London. Described as “the Guggenheim in Bilbao turned on its side and then beaten senseless with a hammer” by critic Walter Ellis the commission was abandoned in 2004.

Visitors will be able to enter the new V&A precinct via the arches of the 19th century screen designed by Sir Aston Webb on Exhibition Road in South Kensington. Director Tristram Hunt said that the new entrance would enable the V&A to “revive [its] original mission, which is the notion of Albertopolis, spreading out on to Exhibition Road”.

The Duchess was said to be especially interested in the engineering of the Sainsbury exhibition space, which required builders to dig 18m under the Museum. “We dug down and yet kept the walls upright and didn’t break a single glassware or ceramics”, Hunt said.

Amanda Levete Architects (AL_A) outshone six other shortlisted architectural teams with its winning design proposal in 2011. With the help of private donations the new development was completed in four years and opened to the public on Friday 30 June.