Architecture practice Llewelyn Davies says the NHS has been trying to introduce sustainability in new hospital design 'within pragmatic limits'.

'Given that this is a current debate and the length of time it takes, we will see the first more sustainable hospitals around five years from now.'

The Department of Health has encouraged low- energy hospitals for 15 years and it would be a 'big mistake' to conclude that not a lot is happening, says a spokesman.

'It is a stated wish of trusts, particularly in the current round of private finance initiative competitions, that sustainability is involved, 'he adds.

The new PFI-financed Queen Elizabeth Hospital opens on an edge-of-town site in Woolwich, south-east London, next spring.

According to a spokeswoman for Greenwich Healthcare trust, the building materials were selected 'from an environmental point of view'.

Low-energy consumption was high on the list of priorities, with the emphasis on as much natural lighting and ventilation as possible.

She adds: 'We're adhering to a green travel policy, including providing cycle racks, bus routes and easy access to hospitals.'