Twinkling like rows of cut-glass decanters in a well-stocked drinks cabinet, the faceted windows atop Cape Town’s new contemporary art museum rise as a crystal beacon above a motley jumble of wharves, warehouses and shopping malls.

The windows shine out from the crown of a majestic concrete grain silo that has stood here since the 1920s, once the tallest building in sub-Saharan Africa, now reborn as the continent’s answer to Tate Modern, which opens next week.

“We could have so easily knocked it down and built a big shiny spaceship of a museum instead,” says Thomas Heatherwick, the British designer of the R500m (£28m) Zeitz Museum of Contemporary African Art (Mocaa), the first such institution of its kind in Africa.

“But the danger would have been that people would just come to take a selfie and not go inside. In a place that doesn’t have a strong museum-going culture, our challenge was to make compelling innards, to lure people in to see the art.”

The building’s guts certainly have the jaw-dropping, selfie-friendly wow factor he was hoping for. In one of his most audacious party tricks to date, Heatherwick has excavated a gigantic ovoid atrium from the centre of the silos, revealing a thrilling space of concrete cylinders that plunge from the ceiling like carved stalactites, through which stairs spiral and glass elevators glide. It is a spectacular act of architectural mutilation that makes Gordon Matta-Clark’s penchant for cutting holes in houses look like mere tinkering.

Such a gravity-defying feat wasn’t easy – in fact, it wasn’t initially possible. The rickety 1920s concrete tubes, at just 180mm thick, weren’t capable of being chopped up so brutally, so a new 250mm sleeve of concrete had to be cast inside each of the cylinders. The building was essentially made anew before it could be sliced up in a Herculean ballet of jackhammers, diamond rope and double-bladed circular saws.

The museum’s atrium at night. Photograph: Iwan Baan

The result, however artificial it may be, is nonetheless a powerful piece of constructed archaeology, the aggregate of the new cylinders contrasting with the old, their edges polished like nougat, while the atrium void plunges through the floor to reveal the basement where conveyor belts once shuttled the grain. How well it performs its role as a space for “monumental interventions”, like the Tate’s Turbine Hall, remains to be seen. For now, Nicholas Hlobo’s dangling creature made of rubber inner-tubes and ribbons gets a bit lost in the soaring geometry.

The next hurdle was how to make the galleries. As Heatherwick admits, “tubes are quite rubbish spaces for showing art,” so two-thirds of the silos have been swept away to make space for conventional white cube galleries, “dropped in like shoeboxes” either side of the dazzling atrium. The resulting spaces are indeed rather utilitarian affairs. The character of the industrial hulk has been banished in favour of white plasterboard walls and suspended grey resin floors, which bounce underfoot with an uneasy cheapness. Thankfully the basement level has been left as a raw, as-found space for installations, but more of the rugged spirit would have been welcome throughout.

If it feels like an amazing atrium with an OK gallery attached, the project’s unusual gestation explains why. What to do with the ageing silo had long vexed the V&A Waterfront, the company in charge of the 123 hectares of former docklands, which has been developed piecemeal since the 1990s as an odd mishmash of retail, office and seaside attractions.

“The silo was our cathedral,” says the company’s development director Mark Noble, “but we had no idea what to put in it.”

The museum (near bottom right) and harbour. Photograph: Iwaan Baan

So they turned to Heatherwick – who had been enchanted by the abandoned pigeon poo-filled relic when he visited Cape Town in 2007 – to come up with a plan.

After considering everything from a mushroom farm to a car park, his studio hit on the idea of a museum. The usual big institutions such as the Guggenheim were approached, “but they all wanted millions in licensing fees,” says Noble. Happily, a connection was made, through Mark Coetzee, a Capetonian curator and now director of the museum, to Jochen Zeitz, a German businessman, who made his fortune from the Puma sportswear brand and whose substantial collection of contemporary African art the building now houses.

The museum, it turns out, would be the value-adding cultural anchor for a much bigger commercial development, the V&A Waterfront’s R3.5bn (£195m) “silo district” of offices, shops and apartments that are now cluttered around the elegant concrete tower in a discordant symphony of competing cladding systems.

Cape Town’s Silo district. Photograph: Oliver Wainwright

Masterminded by the local architecture practice VDMMA, it is a dog’s dinner of tiles, bricks and corrugated metal at wonky angles, housing the offices of PwC, a Radisson hotel and a Virgin Active health club. It is the usual formula of museum-led real estate development familiar to cities around the world, where developers flock to cash in on the cultural caché that a new institution brings to an area, only here it has happened in reverse: the luxury apartments are sold before the museum has even opened, the whole thing planned by one landowner.

The commercial leaning of the whole enterprise isn’t confined to the surroundings. The glowing crystalline lanterns atop the museum are not, in fact, gallery spaces but the bedrooms of a luxury hotel that occupies the entire upper half of the complex. Managed by South Africa’s exclusive Royal Portfolio brand, its interior (not designed by Heatherwick, his team is keen to stress) is a vision of gaudy opulence, like a site-specific artwork of more money than taste. The bedrooms, which cost between R12,000 (£680) and R140,000 (£8,000) per night, groan with two-metre Egyptian chandeliers and lime-green ostrich skin. Looking out through the chunky steel frames of Heatherwick’s quasi-gothic windows makes you feel a little like a caged songbird.

A conventional white cube gallery. Photograph: Zeitz Museum of Contemporary Art Africa

The stunning poolside bar on the roof, where you can enjoy a R3,800 (£200) glass of cognac and views of Table Mountain, is, of course, accessible by reservation only. Compare this with other recent museums, like Tate Modern’s Switch House with its free public roof deck, and the difference is stark.

“You can only take philanthropy so far,” says Noble. In this case, just up to the sixth floor, where museum-goers can enjoy a small sculpture terrace overlooked by residents of the hotel’s luxury suites.

Both Heatherwick and Mocaa are reluctant to talk about the hotel, and it’s not hard to see why. For an institution that is trying to be open and accessible to all, its upstairs neighbour is a painful reminder of the extreme inequality that still racks this city – a luxury playground for some, an impoverished slum for others – more than two decades after apartheid.

Still, it might prove to be a useful tension, given that this entrenched status quo is exactly what the museum should be here to challenge.



• Zeitz Museum of Contemporary Art Africa opens on 22 September.