Speaking out for the first time yesterday, the Parents and Citizens Association of the school said no one had been able to tell them why the 7m by 11m Building the Education Revolution project was costing about $850,000, making it one of the most expensive buildings ever constructed in the state on a square-metre basis.

P&C president Brett Lees said the school had initially been reluctant to voice its concerns as it was grateful to be receiving the first major new infrastructure in years, but had become concerned that what they were being given under the program was not good value for money.

''We've got a P&C member who in the last nine months has built a four-bedroom home, probably four or five times the size of our new school library, for maybe less than half of what it's costing us. So when people start talking about those sorts of figures you think, hang on, this isn't right,'' Mr Lees said.

According to property advisory and construction management practice Rawlinsons, which publishes the industry-accepted guide to construction costs, some of the most expensive buildings to construct such as a five-star hotel in Sydney's CBD cost between $4800-$4920 a square metre. Based on the P&C's measurements, the Gunning library is costing around $11,000 a square metre.

Rawlinsons director Paul McEvoy said unless it was built on the side of a cliff, the most a primary school library within 200km of Canberra should cost is around $1970 a square metre.

''If the $11,000 is correct, it is far in excess of what one would expect, it doesn't sound like good value at all.

''You would expect a university library three storeys high, that would cost between $2500 to $3000 a square metre ... and that figure includes $517 for air conditioning,'' Mr McEvoy said.

Mr Lees said the site had no major slope or other complications that could explain the high cost. Despite the small size of the new library, the school community would also have to resort to selling sheep droppings through its annual fund-raiser because not enough money would be left over to pay for renovations to an administration block.

For more on this story, see the print edition of today's Canberra Times.