The rule of the car and sick building syndrome is blamed by prince for health problems such as obesity and asthma.

Prince Charles has once again weighed in to the state of British cities by attacking “sick building syndrome” and poor urban planning for a host of social and health problems.

The prince said that health problems like obesity, allergies and asthma could be linked to the cavalier attitude from planners and the building industry.

Speaking to delegates at a conference on the healing environment in London, the Prince said: “We are beginning to see that when we build badly, it doesn’t only affect the health of the natural environment, it affects our own health as well.”

He added: “We are slowly discovering that if we plan our towns and cities with the car at the centre of the design process, instead of putting the pedestrian at the centre and thereby creating attractive and well-organized human-scale neighbourhoods, it is likely to have an adverse effect on, for instance, obesity, heart disease, asthma and respiratory diseases.”

“Neighbourhoods with a strong “public realm”- such as public gathering areas, buildings connected to the street and a diverse mix of shops and recreational areas - seem to have much higher levels of what the sociologists call “social capital”.

Prince Charles’ intervention follows a conference on new urbanism at his Prince’s Foundation in November, at which he decried 60s-era town planners for producing “watered-down Le Corbusier”.

It also follows deputy prime minister John Prescott’s apparent endorsement of US new urbanism at the urban Summit earlier this month, where he chaired a debate featuring John Norquist, head of the American Congress for New Urbanism.