THE cost to the taxpayer of going green at two Government offices in York is a controversial £28.3 million.

The bill is being run up during a refurbishment at the Department of the Environment, Food And Rural Affairs' (Defra) offices in Kings Pool, off Peasholme Green, aimed at making the buildings more "sustainable".

The extensive buildings were constructed 14 years ago.

The work, which includes the installation of solar thermal hot water, rainwater harvesting and ultra-efficient gas-fired boilers, will save 15 tons of carbon a year - equivalent to the typical emissions from nine UK houses.

Hilary Benn, Secretary of State for the Environment, Food And Rural Affairs, speaking during a visit to York, robustly defended the expenditure, saying it was essential that everyone - from Government to individuals - reduced their carbon emissions if the world was to avoid rising sea levels and other environmental disasters. He insisted the project was not a symbolic gesture, but a practical measure which would prevent damaging carbon being poured into the atmosphere.

"We are all going to be affected by climate change and we all have a responsibility to do something about it," he said.

But the spending was branded "extortionate" by Graham Bowers, of the PCS union, which represents many civil servants on the site, where more than 800 people are employed.

He claimed carrying out the work would in itself create carbon emissions, for example, through the transportation of materials, equipment and workers to the site, negating the benefits.

"Goodness knows how many years it will take to recoup that," he said.

He also claimed the project came at a time when the Government was cutting expenditure elsewhere, resulting in fewer civil servants doing more work, with a resulting drop in morale.

Michael Watkins, head of estates, said: "The two office buildings at York are being refurbished in an industry-leading way, minimising waste output while maximising the recycling of any waste materials produced.

"In addition, the new Social Hub a staff social meeting and conferencing area has been designed to have a minimal carbon footprint through the use of low-carbon features, including sun pipes, above average thermal insulation properties and a green roof system which will also help improve the local ecology, in conjunction with the new improved landscaping."

He stressed the costs at Kings Pool had been higher than might normally be expected because the work was having to be carried out with staff in situ.

Workers were having to be moved to offices at Monks Cross while the refurbishment happened in their area, resulting in the department have to pay rent on two buildings at once.

He added the project would also increase the number of available workstations from the current 850 to 1,150 in a naturally-ventilated open plan modern working environment, together with the Social Hub extension and business centre.