Government research due this autumn will come out against building new settlements and extensions to villages.But the new policy has angered the House Builders Federation, which does not believe that demand for new housing can be met in urban areas alone.The research findings will intensify the Government's planning policy trend of encouraging development on waste and under-used sites in towns instead of green field sites.Housing and planning minister Sir George Young told planners last week that the departments of the environment and transport had commissioned the research jointly on ways in which the planning system could be used to discourage car travel.This is part of the Government's effort to cut carbon dioxide emissions in line with commitments it made at the UN environment summit in Rio last June.Sir George told the town and country planning summer school: 'The planning system cannot force people to walk or cycle or use public transport. But it can encourage development patterns which provide a greater choice which does not depend on ever-increasing use of the motor car.'He said research showed the planning policies would help to cut carbon dioxide emissions, but could not do so alone. Road pricing, lower speed limits and parking controls would be needed.Sir George wants developments which reduce the need for people to commute, with both new shops and industrial and commercial developments built in existing urban areas which are served by public transport.David Coates, land and planning officer of the HBF, said ministers seemed to have changed policy completely from the mid-1980s, when they 'gave a strong lead to new settlements'.He said: 'Even if there was scope for development in urban areas it would be resisted by local authorities because they are worried about town-cramming. Just look at the restrictions they have put on conversions because they are worried about congestion and demands on local services.'