The spokeswoman said she was aware of only two Christchurch inner-city schools, pre-earthquake, that had not had playing fields.
Auckland Primary Principals' Association president Jill Corkin said communities were being caught between a rock and a hard place. Some would have to accept two-storey blocks of classrooms as the only way of preserving playing grounds.
"We don't want to come to a point where schools have a small dusty piece of turf or hard asphalt to run about on at playtime," said Corkin.
However, the playground shrinkage has been in full charge for some time, with extra classrooms eating up school grounds for years.
In the past couple of weeks, six relocatable classrooms were moved on to Northcote Primary School's one playing ground on the North Shore. It was a temporary measure until a new eight-classroom block was built next year, but it meant pupils lost the majority of their grassed area for the next 12 months.
Board of trustees chairperson Monique Geenty said children had an ashphalt court area to play on at the school in the meantime.
New Zealand Secondary School Sports Council executive director Garry Carnachan said NZ schools had good playground spaces and hoped it could be maintained.
"Compared to overseas schools we are very lucky that schools regard physical activity so highly and that our schools plan large spaces for play and hopefully will continue to do so," Carnachan said.
A ministry tender document identifies the South Auckland suburbs of Mangere, Otara, Otahuhu, Papatoetoe, Manurewa and the upmarket Eastern Bays as key growth areas of school-age children in the next five years.
The ministry is attempting to forecast the future rolls of state and integrated schools as far out as 20 years so schools can develop property plans to meet the needs of thousands of Auckland families. It affects primary, intermediate and secondary schools.
The ministry spokeswoman said approximately $35 million was allocated each year for roll growth with extra money available for more classes if needed.
The Auckland Plan targeted South Auckland for high-density housing programmes which would put more through local schools.
Principals' spokeswoman Corkin said high density housing, and smaller sections, meant school playgrounds were even more significant.