The density of new housing developments has risen by more than 50% in the past four years, breaking 100 dwellings per hectare in London for the first time, according to official figures.

The density of new housing developments has risen by more than 50% in the past four years, breaking 100 dwellings per hectare in London for the first time, according to official figures.

The statistics, published last week, show that the average housing density in Britain was 42 dph last year, up from 25 dph in 2001. In the capital the average density was 102 dph, more than double the figure of 48 dph in 2001.

The main increases took place in London and the South-east, following deputy prime minister John Prescott's threat in 2002 to call a public inquiry into any scheme that fell below the 30 dph minimum outlined in PPG3. The average density of schemes in the affected areas has nearly doubled since then. The region with the lowest average density was the West Midlands where the figure dropped from 37 to 35 dph in the four-year period.

The same figures also show that the proportion of housing built on brownfield sites edged up from 72% to 73%.

John Slaughter, the Home Builders Federation's external affairs director, said the rate of increase was unlikely to continue, given that the recent increase in the number of flats being developed was unlikely to be sustained.

But Kate Gordon, planning campaigner for the Campaign to Protect Rural England, said: "These figures show that PPG3 has not led to a block on development but to more efficient use of land."

Gideon Amos, Town and Country Planning Association director, said: "High densities need to be balanced with design and space standards."