New buildings should be built to a "high environmental standard"

The government wants 800,000 new homes built in the region but the agency said the environment should be considered at the planning stage.

In its State of the Environment 2004 report, it said flood plains should be kept free from development.

Extra waste, sewage and water plants should also be built, it said.

Now is the time to do something to safeguard our future Howard Davidson, Environment Agency

The government-appointed body said on Wednesday that a growing population means more demand for housing, water and energy

It also warned of the dangers associated with climate change which result in violent storms, rising sea levels, floods and droughts.

"The development of a 25% increase in housing will exacerbate all of these threats to the environment," the report said.

Recommendations to minimise the effects of increased population include ensuring enough green spaces to absorb excess carbon dioxide, and improving energy and water efficiency.

'Wake-up call'

The Environment Agency also wants buildings to be developed to a high environmental standard.

Howard Davidson, director for the Southern region said: "We have a real opportunity to make sure that the environment is considered at an early stage of any planned development.

"This is the only way that the environmental impact of the building of 800,000 new homes can be managed."

He said climate change was a "wake-up call" that the environment must be protected.

"Now is the time to do something to safeguard our future," he said.