They raised $130 to purchase Taking the Lead (Ardern), Whina Cooper, Sky High (Jean Batten) and Kate Sheppard.
"I am really excited about the response from the Prime Minister and the students were so excited to receive the letter."
Ardern thanked the class for the letter and petition.
"I absolutely agree that all children in New Zealand need a healthy, safe and warm home to live in," she wrote.
"I am delighted to hear your class is learning about how people can work together to create effective systems and enable change.
"Nobody is too young to get involved in trying to make change happen and I congratulate you for thinking about this and taking positive action.
"The subject you have written to me about is one I feel very strongly about and it is an absolute priority for me.
"Since I became prime minister my government has done quite a lot to make sure children have healthy, safe and warm homes but I know there's still work to do."
She said some of the things the Government had done included:
* New rules so landlords must ensure the houses they rented out were warm, dry and safe.
* New laws so landlords can't increase rent more often than once a year.
* Homelessness Action Plan (which included $300m of funding) to stop people becoming homeless.
* Put aside $400 million aside to help people buy their own home.
* Agreed to $570m being spend over the next four years to provide houses for families to live in if they don't have their own home [enough money for about 8000 new homes].
"You can see we are coming up with a lot of new ideas to help solve the housing crisis in New Zealand.
"It is not an easy thing to fix but it is a priority for me so I will continue looking at what can be done and working on this with colleagues."
