It’s a sunny Thursday afternoon and residents of the Rudolf Seniors Home – Helsinki’s largest state care home – are eating raspberry swiss roll and having a spirited guitar singalong to some traditional Finnish tunes.

Among the trestle tables and rocking chairs occupied by the elderly Finns in the common room is someone considerably younger. Eighteen-year-old Serafina Eljaala is one of three young people who live in the care home. In exchange for cheap rent she spends five hours a week socialising with its more traditional clientele.

“It is cool living here – I have become more sociable and I like hearing the older people’s stories. It has also taught me to appreciate my own health and youth,” says Eljaala, who has been drinking coffee and sharing a songsheet with one of her older companions. She explains that they are celebrating because today is the name day of Roosa (Rose) and the care home has a floor of the same name.

The pilot scheme she belongs to is part of a wider city-funded initiative called A Home that Fits, coordinated by the council’s youth department. It hopes to ease youth homelessness in Finland’s capital and at the same time relieve the social isolation felt by some of Rudolf’s 140 residents.

Three spaces have been made available to 18- to 25-year-olds at Rudolf since the pilot began in 2015, with the help of some initial funding from the European Social Fund. Four other Finnish cities have launched their own versions of the model, and a number of others are expected to follow suit.

It has been very uplifting for the spirits – I’m excited when I get a visit and everyday life is not so boring Taimi Taskinen, aged 82

A fourth apartment is being made available at Rudolf in the autumn. Six young people have benefited so far, including students, a pastry chef and a kindergarten teacher. Each has faced their own set of housing difficulties.

For Eljaala, who has lived at Rudolf for almost six months, the scheme has provided an escape from a troubled family life. “In Helsinki rent is really expensive. I couldn’t afford to live anywhere else,” she says.

Affordable housing is hard to find for young people and homelessness among under-25s is a growing concern, says Miki Mielonen, project manager for the youth department of the city council and founder of Homes that Fit.

“Official figures suggest there are about 700 homeless people under 25 in Helsinki but the reality is at least three times bigger [because] youth homelessness is more of a hidden problem,” he explains. Some of the people the scheme has housed so far had no permanent address and were sofa-surfing at friends’ houses, while at least one was facing a life on the streets.

“More and more young people are moving to the capital region; Helsinki is growing by about 8,000 citizens every year and just building new apartments does not solve the issue,” he adds. The scheme was first advertised on Facebook and Mielonen had emails from more than 300 young people within a matter of weeks.

Rent at Rudolf is €290 per month for a small studio apartment with a balcony; less than half of the going rate in Helsinki, where even the most basic accommodation can command €600, according to Mielonen.

The care home is bright and thoughtfully decorated with plants and colourful wall hangings, but it is also old and in need of renovation. “The young people are given rooms which aren’t really suitable for the elderly residents any more,” explains Kristiina Stenman, one of Rudolf’s social workers. For example, Eljaala lives right by a flight of stairs, where it would be difficult to safely manoeuvre a wheelchair.

Drawings in the hallway of the care home by visiting kindergarten children. Photograph: Jussi Eskola/Getty Images/Jussi Eskola

Rudolf was waiting for an opportunity like this to come along, Stenman says. “The youngsters have brought an energy and positive spirit into the place with them. It is a very simple model that would be easy to spread to other countries.”

She has seen the scheme benefit people like Taimi Taskinen, a resident at Rudolf for more than 10 years. “It has been very uplifting for the spirits – I’m excited when I get a visit and everyday life is not so boring,” says the 82-year-old, who has had Jonatan Shaya, a 19-year-old pastry chef, living next door for 18 months.

Together they enjoyed reading the newspaper aloud, drawing and painting things from the chef’s favourite children’s book, Charlie and the Chocolate Factory, and baking (and then eating) cinnamon rolls.

“I loved living there and it helped me to get my new apartment because I was able to save a lot of money,” says Shaya, who moved into Helsinki city centre a few weeks ago. He thinks the scheme also helped to make him a more attractive tenant – he wrote a letter to his current landlord about the project and the life lessons he learned while living there.

In the UK, where a combination of high rents, low wages and cuts to benefits has seen a huge rise in youth homelessness, there has been some criticism of schemes that offer cheap rents in an elderly person’s house. Cash-strapped young people who have signed up to provide companionship and help around the house report that in some homesharing schemes they have been pressurised to do the sort of social care they are neither paid nor qualified to carry out for their elderly hosts. At Rudolf, this scenario is avoided says Mielonen. “The young people do not take on staff-type roles because there are plenty of staff for that – they are just supposed to be good neighbours to the seniors.” “We think it is very important to keep these roles strictly separate and [for that reason] we don’t choose young people who are studying or working in the social welfare field.”

The set-up is much more relaxed, too. Eljaala keeps to her five-hour commitment, but doesn’t feel like she is clocking in. “I first had some doubts – what if it becomes like work and I get tired of it? But I can decide for myself what I want to do and with whom,” she says. “Everyone is always so open and happy to see me that it doesn’t feel like work at all”.

Baking has become a popular activity and Eljaala plans to make Karelian pies next, a traditional Finnish pastry served with egg and cream, which she thinks will be nostalgic for the female residents to help prepare.

“We have also been going to concerts, singing together – or just sitting and chatting over a coffee. Sometimes we might take a walk outside – just whatever comes,” she shrugs with a smile. “A lot of the elderly people tell me they are so lonely, and it isn’t the same to have nurses because they’re here as a job – it would be really great to have more young people around for them to talk to..”

The model has attracted international interest as cities across the world grapple with their own housing problems. Mielonen was recently invited to showcase the project at an age services conference in Australia, and he has been busy fielding delegations from Stockholm and Denmark. This summer there will be visits by interested parties from Belfast and Pennsylvania.

But not everyone thought the scheme would be the success it is today. “Some of my colleagues in the city council said it wouldn’t work because [the young people] are going to party all night long, and who will pay if something is smashed up,” remembers Mielonen. Everybody in the room chuckles at the idea. Taskinencertainly has nothing negative to report. “It’s important to have young people around and that they have fun – we are from big families and we are used to being with lots of people and noise,” she says. “I would like there to be more noise, more music playing and guitars, it can get too quiet here.”