Chang’s description – from his 2008 book, My 32m2 Apartment: A 30-Year Transformation – refers to the sliding walls that fit over his bathtub.

Architects, designers, students, film crews, journalists – myself included, 10 years ago – and even tourists have crossed the threshold of Chang’s flat to see its push-me/pull-me systems work with pivoting, folding, retractable furniture that give the home extraordinary shape-shifting powers.

Maximising space and storage makes a micro-apartment liveable

In 2020, the museum commissioned a 1:1 copy for its free-to-the-public temporary exhibition “Hong Kong: Here and Beyond”.

“Several developers have flown deliberately to Hong Kong to visit my home,” says Chang. “Now I can say, ‘Please visit M+.’”

Not for much longer.

After the exhibition ends, on June 11 – to be replaced by “Sigg Prize 2023” finalists – the architectural installation will be returned to Chang, because, as a statement from the museum reads: “M+ has decided not to acquire the Domestic Transformer as an object.”

Where to relocate the facsimile, however, has con­founded the designer. More dispiriting is that it could end up being scrapped if it does not find a buyer soon.

“My home,” Chang says for hyperbolic effect, “is homeless.”

M+, designed by renowned architects Herzog & de Meuron, has attracted 3.2 million visitors since opening in late 2021, after years of delay. Many will have made a beeline for “DT2” (my nickname for the reproduction), one of the Hong Kong exhibition’s highlights.

One of 23 flats per floor in a standard 17-storey, 1960s block that once enjoyed harbour views, the Domestic Transformer is an artefact of Hong Kong’s urban develop­ment and high-density living.

As Tina Pang Yee-wan, curator of Hong Kong visual culture at M+, says: “Housing was a theme that we felt was really important. It’s such a sharp issue that touches everybody’s lives.

“We knew very early on that we wanted to find a way to represent the project in the exhibition, to give a sort of positive perspective on how we can live better and live well in small spaces.”

But while visitors might appreciate the design DNA the Domestic Transformer shares with its twin, it is important also to understand some of DT2’s own history and quirks.

Manufactured in Dongguan, Guangdong province, during the pandemic, the installation was trucked to Hong Kong in three pieces and put together at M+ by the same contractor Chang had enlisted in 2007 to help him realise his ultimate home. And it will probably be the same sifu who cuts the cord.

Often compared to a Swiss Army knife for its utility and versatility, the Domestic Transformer has allowed Chang, 60, to live large in a small space.

Nothing, save for the flat itself, is undersized: the shower is a roomy – and pricey – Kos chromotherapy cabin; his Sharp television has a 37-inch screen and the bathtub is a standard-issue Duravit.

How Chang lives in the flat – with his Murphy bed and a pivoting table-cum-work desk 2.2 metres (7ft 2 in) long – is for all to see in videos widely available online and on a screen alongside the M+ installation.

Instead of rooms choreographing his movements, he is in command, allowing 24-plus configurations as needs arise. “So I don’t need to move,” he says.

The Domestic Transformer also stars in an episode of Apple TV’s 2020 docuseries Home, about “the world’s most imaginative dwellings”. Aric Chen, one of a handful of interviewees, says: “It’s in many ways almost like a design for a spaceship.

“In a spaceship you have to be very compact, every square inch counts and is accounted for, and that’s pretty much what Gary has done.

“He’s basically realised the dream of the ultimate flexibility and adaptability of space,” the former M+ curator of design and architecture adds.

Design of the original took six months to complete, although in reality ideas were tried and tested during previous iterations. At one stage, the interiors were a blizzard of white, with a bed in the middle surrounded by snowy curtains concealing utilities on both sides of the flat.

For the Domestic Transformer, Chang says he “was very much inspired by those office cabinet systems that glide”.

Everything Chang cannot fit into his home seems to be here – including a couple of African djembe drums.

There is even a true-to-scale news-stand to house the umpteen publications worldwide that have featured his work to date, which spans interiors – a private jet among them; architecture – his pneumatically aided configurable Suitcase House in Beijing has won many awards; and product design – an improved Light Hotel, a cylindrical floor lamp with countless illumination arrangements, is next to his bed at M+.

But it is the Domestic Transformer that continues to be studied by everyone with a stake in efficient living. Interest has come from as far afield as MIT Media Lab’s Hasier Larrea – who, with renowned designer Yves Béhar, created the Ori system of robotic furniture – and even Ikea.

Chang’s own obsession with the Domestic Transformer is understandable. In the 1970s, the former rental property, his home for the past 46 years, accommodated his parents, three sisters, himself and, improbably, a lodger – a woman in her 20s whose family lived nearby.

While still a teenager set on becoming an architect, Chang began conceiving room improvements. Then, he slept on a bench that folded out into a temporary bed in the living room after everyone had retired for the night.

Transformation for the same purpose continues to this day. At night, Chang pulls down his bed in an area otherwise occupied by seating in front of a television.

That design was part of his fifth refurbishment, which gave birth to the Domestic Transformer in 2007, the same year the Transformers sci-fi action films began.

Minor improvements have been made since. A few years ago, groovy yellow-tinted windows at the front of the flat were replaced with clear fluted glass for privacy.

Earlier, because they marked the floor, wheels were raised from the bottom of the unit’s five mobile walls suspended from ceiling-mounted tracks.

In 2007, the groundbreaking flat cost about HK$2 million to renovate – more than five times the HK$350,000 Chang paid in 1988 to buy the property after his family had moved out.

DT2, built for an undisclosed sum, is better than the original, Chang readily acknowledges. When the museum initially expressed interest in his home, he says, he felt honoured. But he wanted an upgrade.

“I advised M+ that I would do an abstract representation of my home,” he says, stressing that both share the same dimensions, a subject he later elucidates.

DT2’s most obvious difference is in the hairline stainless steel used throughout the installation. In contrast, Chang’s home was built 16 years ago with “G-shot” steel, which has a hand-brushed effect.

Some surfaces in the Domestic Transformer are white, the floor is granite and the ceiling is clad in mirrors to help conceal the tracks, more refined versions of which are used at M+.

Chang also has a lifetime’s collection of music and films. Representing their disc cases, thousands of clear acrylic boxes are neatly stacked on backlit shelves at DT2 that lend the aura of a sanitised laboratory.

At home, the films are projected onto a drop-down screen that doubles as a blackout blind.

Keen observers at DT2 might also notice that the bench beside the big windows is missing, one reason being that museum visitors might be tempted to use it. Attached to the underside of his remote-controlled bed at home, the seat can be folded down manually when the mattress and frame are stowed upright.

Even the few mistakes have poignancy, given the historical circumstances behind DT2’s construction. The metal grate door in front of the entrance is much taller than it needs to be, and the kitchen sink is half its intended size.

“It’s funny. A lot of Hong Kong people visit my ‘home’ as though they’re visiting a show flat,” says Chang, referring to DT2. “They look at ‘my apartment’ [to judge] whether it works for them or not.

“One time I was there and a housewife said about the sink, ‘It doesn’t work! How can you wash your dishes in something so narrow?’”

On learning about the sink, Pang recalls the Covid-related restrictions at the time of DT2’s construction in mainland China, which made travel from Hong Kong difficult.

“We had planned for our technicians to go up to Dongguan, where it was built, and to do multiple site visits,” she says, adding that phone-footage reviews became their only recourse. “But, of course, you can’t see any details. So in a way it was delivered to M+ sight unseen.”

DT2 was the first work installed at M+, and “it took a bit of elbow grease to fit [the three pieces] together, but once they were fitted together everything worked”, says Pang. “I was quite stunned.”

The consequences of the pandemic are felt in other ways, too. Visitors are not allowed to lay their hands on anything inside DT2, a rule with viral roots. When Covid had Hongkongers fearing contagion, few wanted to touch anything in public anyway.

Safety concerns also mean that visitors are not allowed to move the walls, lest anyone be trapped accidentally. But fingerprints on surfaces inside betray visitors’ unbridled enthusiasm, despite gallery attendants’ “Don’t touch” imprecations.

“How can you do an installation like this but not allow people to move things?” says Chang. “It kills the whole purpose.”

Which means visitors will just have to believe him when he says that the stainless-steel pulls on the sliding walls have great hand feel: a salient detail for anything you are likely to touch frequently. But in truth, the upgrades make transformation in DT2 so effortless that its walls, though heavy, can be moved with just a pinky’s pull.

If DT2 is a well-oiled machine then credit must go to all involved. That includes Chang’s main contractor, Leo Chiang Chiu-yeung, who recently built interiors for himself, inspired by the Domestic Transformer.

“He got quite obsessed,” says Chang, describing how the walls in his contractor’s Shau Kei Wan flat move by remote control. “It’s not that sophisticated but it’s fun. It’s fantastic actually. I posted about it on Instagram.”

On March 26, Chang again took to Instagram, this time to publicise DT2’s forthcoming eviction. “Last 3 months to visit my ‘second home’ at M+ Museum Hong Kong,” read his breezy post.

Its follow-up was somewhat darker: “Hurry! … before my second home here to be dumped somewhere as trash!”

“I was a bit frustrated because the deadline is approaching,” he says. “My home cannot contain my home.”

His statement is also imbued with regret: Hong Kong stands to lose DT2, the ideas for which were home-grown.

An M+ statement reads: “We believe the project to be one of the uniquely ingenious ideas borne out of Hong Kong that has global significance. This is why we collected the models of the project for the museum collection and why we additionally commissioned the 1-to-1-scale replica in order for our audiences to experience it physically and be inspired by it.”

As for why the museum is not collecting DT2 – after so much effort and expense have gone into its creation – Pang says “there are all sorts of considerations that go into acquisitions that are separate from com­mis­sioning”, among them collection care and maintenance.

She reiterates that DT2 “was commissioned specifically for the [Hong Kong] exhibition”, and the show always had a lifespan. Also that although M+ paid to have the reproduction built, it does not have rights to it.

“Production costs are production costs, but of course what you’re not purchasing is the idea,” she adds. “That’s intellectual property that belongs to Gary.”

Not willing to scupper potential deals by saying who, what, when or exactly where, Chang will reveal only that, since being informed of the decision late last year, he has pursued solutions in mainland China and in Hong Kong.

The likeliest scenario is that a mainland museum takes DT2, although in moments of despair Chang vows he will “destroy and dump” the installation when the exhibition ends. “It’s just like most things in Hong Kong – they come and go so fast,” he says. “Nothing remains.”

Because of the installation’s size, it is limited in where it can travel. Originally expecting the museum to collect the work, he says, he designed DT2 in pieces that could be put on a truck and driven to Hong Kong.

“I didn’t make them small enough to be put in [shipping] containers,” he says. “I assumed that it would be collected. Everybody assumed.”

The same could be said about a crucial point connected to the Domestic Transformer that everyone has always believed to be true: its size. “I’ve always told people, since the beginning, that it is 32 square metres,” says Chang. “I regret this. I made a mistake.”

Laughter accompanies his confession. “It’s 30.7 square metres,” he says, lamenting “giving up” 1.3 square metres. “One-point-three square metres in Hong Kong means …”

When every millimetre matters, 1.3 square metres is not an area to be squandered. It is, in fact, about the size of his bathtub.

Gone to seed

The fate of other famous large-scale works commissioned for temporary exhibitions.

Sunflower Seeds, by Ai Weiwei

Most of the 100 million porcelain seeds that made up the installation, commissioned by the Tate Modern in London and made in Jingdezhen, the “porcelain capital” of China, were returned to Ai Weiwei on conclusion of its temporary exhibition in 2010.

The museum bought 8 million seeds for permanent display. Some were stolen by visitors. The artist exhibited the rest, in various scales, elsewhere around the world.

Tower of the Sun, by Taro Okamoto

A symbol of the 1970 Japan World Exposition in Osaka, the surreal, 70-metre-tall, totem-pole-like structure was slated for demolition after the close of the six-month-long event. But public opposition led to preservation of the government-commissioned work.

In 2018, after reinforcement, the tower was reopened permanently.

Serpentine pavilions

Every year an accom­plished architect is selected to build a temporary pavilion at the Serpentine Gallery’s site in Kensington Gardens, London.

The pavilions – some of which sell even before they are built – are then relocated: the 2016 pavilion, designed by Bjarke Ingels Group, was bought by Westbank Corporation and shipped to Vancouver, Canada; the 2017 pavilion, designed by Diébédo Francis Kéré, was bought by Kuala Lumpur-based Ilham Gallery, and is now in Malaysia.

Ilham Gallery is in talks to secure a suitable location for the structure.