A national scheme that invites Singaporeans to come up with ideas and solutions to improve HDB living has had only a lukewarm response since its launch.

Though the housing board has received more than 500 ideas from the community since its "Cool Ideas for Better HDB Living" initiative was launched in 2011, none of them has been implemented on a large-scale in HDB estates.

A $500,000 Cool Ideas Fund was introduced in 2014 to allow people to develop their winning ideas into prototypes or take them into the market but no money has been disbursed so far.

Yesterday, HDB ran another variation of its Cool Ideas competition, this time in the form of a hackathon. Winners get cash prizes and the opportunity of test-bedding their ideas in existing HDB towns.

Minister for National Development Lawrence Wong, who awarded participants their prizes at the HDB Hub in Toa Payoh, reminded the audience in his speech to turn their ideas into reality.

"We are truly serious about wanting to move beyond just a hackathon by actually seeing your ideas and apps translate into real solutions on the ground," he said, adding that they will be able to test-bed their ideas in HDB estates with help from HDB officers.

He emphasised that the competition is meant to achieve tangible results. "This is not 'play play' and then (when it is) finished, you go home with a prize," he said. When asked why no ideas came to fruition on a large-scale and why the fund was not being used, a HDB spokesman cited some reasons.

"In some instances, the inventors have changed their focus areas and do not wish to pursue their winning idea anymore. There were also winning solutions which we have assessed to be unsuitable for implementation at HDB estates," she said.

There are 27 winners yearly from its various Cool Ideas competitions organised for constituencies, students and the online community.

The HDB spokesman said three of the winning ideas - a swing rack, sustainable plant box and flyer separation tray - in the past have been successfully piloted in some HDB estates. But they were not extended to others because the inventors either did not want to take their projects further or have commercialised them on their own.

Going forward, HDB said it will set aside around $600,000 for the Cool Ideas Fund over the next three years to support some 60 potential good ideas.

A total of 206 participants took part in the three-day Cool Ideas hack, where they were given data sets to develop technology-based solutions to enhance community bonding and living in HDB towns.

There were three categories - student, start-up and open - and the first prize winners for every category came up with an IT solution that connects people in their neighbourhoods or schools.

Student Marcus Yeo, 22, and his team, for instance, came up with an app to let residents find fellow neighbours who are interested in doing activities together at certain times.

"When I want to play basketball nearby for instance, I don't know if there are people to play with and if they are there at the court," he said.

"Technology is able to strengthen community spirit by bringing neighbours together which could have happened only through chance encounters in the past," he added.

He said his team "definitely wants to create an actual app that people can download but is not sure of its eventual scale".