Wu admits that it wasn’t as easy to convince the tight-knit community to host the festival as it was people in more expat-centric areas such as Stanley Market. “It was a bit trickier at first, as they have not experienced an organised street art festival before and don’t know what to expect,” he says. “But we hope by doing something energetic and positive to the community, they can see we are really here to share our love for the arts.”

The organisers met some friends from the neighbourhood who helped introduce them to the local community. Among them is Jackaline Chow, who was born and raised in Sham Shui Po and whose family has not only donated a wall but an entire building to the cause.

“I knew the founders before they even started HKwalls,” she says. “Two years ago they started the project in Sheung Wan and they did a really good job. I love beautiful things, and they made the old district become lively.”

When she heard they were looking for walls in Sham Shui Po, she asked her family for permission to paint their building, and they agreed. Madrid-based Spanish artist Okuda flew into Hong Kong and in three days transformed a worn-down, dirty old building into a rainbow-coloured three-dimensional work of art.

“This building was 20 years old, and now he has painted it, it looks brand new,” says Chow. “My family was really wowed, and people walking past stop to take pictures.”

Sixty-year-old Mr Yu of fabric store Flying Dragon is also pleased with the way his mural has turned out. “A lot of people came round to say they love it,” he says. “There will always be somebody who won’t appreciate it, but there are also people who will really enjoy it.”

“Street art will change the image of the neighbourhood,” says Michael Tam, owner of Café Sausalito, which opened in Sham Shui Po in 2014. Born in Hong Kong, Tam grew up in California, and returned to the city in 2011. “It’s known as an old and really poor neighbourhood of Hong Kong, but having some street art is definitely changing the place up, giving it more of a Brooklyn feel – a much more artistic feel.”

A mix of international and local artists are taking part this year, including Belgian-born Caratoes, Peeta from Italy, Mexican artist Paola Delfin, Okuda from Spain; new additions to the local roster are Katol, Mic and Ryck.

“About 20 years ago Sham Shui Po was very busy because of the garment industry,” says Chow. “Hong Kong was a middle point for people to place orders with the Chinese factories. But now the China market has opened, the business here has slowed down a lot. That’s why can see a lot of shops empty for a long while.

“But lately it’s changing, you can see new people coming. It’s a great thing because it brings life to Sham Shui Po again.”

There’s always a potential downside to urban renewal and gentrification, says Wu. “Once cool shops, restaurants and events start to happen, more people are attracted to the area and the rent goes up,” says Wu. “It’s a vicious circle. The only solution we can see is if property developers and the government see it is an investment to give the creative community a low-rent place to create work. They should see they need us as much as we need them.”

Tam believes the change taking place is a positive one. “A lot of small boutiques are moving in because more vacant shops are available, and people are moving out of factories to settle into shops. So it’s working out pretty nicely. We’re trying to keep it as homely and boutique as possible.”

How will older residents, most of whom have lived in Sham Shui Po all their lives, react to the street art makeover the area is getting? “Actually quite a few old people came to speak to me while I was painting my wall, and the feedback so far has been positive,” says Hong Kong-born street artist KristopherH. “Hopefully they will like it when the mural is finished. The population in Sham Shui Po is ageing and sometimes it’s hard to communicate with them regarding art and design nowadays, so hopefully having artwork right next to them will help them to understand, or even participate.”

“Like all art, it’s always subjective,” says Clogtwo, a street artist from Singapore, adding that he was astounded by the beauty of the dilapidated buildings and the authentic character of the area. “I hope that with a slight change in their routine lives, we’re able to generate a current within the flow of the human traffic – a disruption that would make them stop, realise and appreciate time and space.”

Italian 3D graffiti artist Peeta aims to create something inspired by the energy of the area that fits with its architecture and plays with the surrounding context. “I’m not just sticking my piece as I could have been doing somewhere else, I’m working site specific,” he says. “I hope that after that particular building will be painted it will increase its symbolic value in the area for its community and gain a new meaning.”

Chow says they also hope the artworks will draw more visitors – local and international – to the area. Walking from one mural to another will give Hongkongers a chance to experience corners of the district that many of them will have never seen before.

“Before, people didn’t have a reason to come to Sham Shui Po, but now they will come over to take a look, so it will bring it back to life,” says Chow.

“It’s not just going to be a place for gadgets and cheap stuff any more,” adds Tam. “It’s changing in a way that people will value the older parts of Hong Kong, along with the new, modern contemporary arts.”

“When a piece of art brings colour and joy to your everyday life, then maybe you realise it’s not so unnecessary after all,” says Ryck. “I hope the owners will find their wall embellished and special, that the neighbourhood will embrace all this free art as their own unique property. If we can bring a bit of joy to people’s lives, then it will be great.”

HKwalls is holding a closing block party on Sunday 27 March at Vans, 124 Cheung Sha Wan Road , Sham Shui Po, and the artists will be in the area finishing their walls.

For details: hkwalls.org