Author Cressida Cowell has renewed a call for the government to invest £100m in primary school libraries, as her final act in the role of children’s laureate.

Cowell said that it was “ever more urgent to introduce a proper, lasting” library intervention, as new research shows that school libraries help to improve academic standards, as well as foster a love of reading in children.

The creator of the How to Train Your Dragon series was speaking after the publication of a new report on her Life-changing Libraries project, the flagship initiative in her three-year term as laureate.

The project saw bespoke, dedicated libraries built in six primary schools across the country, each stocked with more than 1,000 specially curated books. The initiative also supported staff with training and mentoring from specialists to develop a culture of reading for pleasure.

Cowell said she “wasn’t surprised at all” at the results of the project, having seen similar research dating back to 2002 that showed the value of schools having their own libraries.

The report found that the schools saw “considerable impact”, including a “transformation in attitudes towards reading, igniting an enthusiasm and passion for books among pupils” and an “increased sense of pride, confidence and self-worth in pupils”.

The project also resulted in “increased attention, engagement and motivation to learn in the classroom” and improvements in pupils’ writing, “particularly in the use of vocabulary and imagination”.

Cowell, whose term as laureate ends this month, said: “I know how difficult it is nowadays to get a child reading for pleasure. The competition for children’s attention is tough, so you really need a school library.”

As well as building the libraries and training staff, the project also supported parents. “The library became a space not only where you get books into the hands of children whose parents can’t afford them, but a space where parents can get involved in reading to their children,” said Cowell.

Last year the author wrote an open letter to prime minister Boris Johnson asking for £100m to be ringfenced for building new school libraries and restoring neglected ones. The letter was signed by all the former children’s laureates, including Malorie Blackman, Michael Rosen and Quentin Blake.

Libraries in schools are not statutory, and research shows that one in eight primary schools has no library space at all. This figure doubles in schools with a higher proportion of children on free school meals.

Cowell said that MPs who had gone into the project’s six schools had been impressed, and that there had been meetings with the government.

“They have shown interest and I really hope that they are considering” the ringfenced fund, said Cowell. It would be a “lasting intervention” that would affect the lives of students long after they leave school.

The Life-changing Libraries initiative was delivered in partnership with BookTrust, and all schools taking part had at least 25% of pupils eligible for free school meals. All developed a “gold standard” library, measured by space, book provision, expertise and whole-school and parent involvement.

Cowell said she would continue to campaign for the improvements after her time as laureate ends. BookTrust will continue to work with the six libraries to build deeper understanding about the role that they can play.