Edinburgh City Council has agreed to consult on proposals to raise the proportion from 15 per cent to 25 per cent on sites of 12 or more homes. This would bring the area into line with the rest of the city.
A report to the council's planning committee last week said the increase is justified by the Lothian housing needs assessment carried out in 2005. The changes will be put out to consultation later this month and would apply to applications submitted after 30 January next year.
"There is an acute shortage of affordable housing across the city, so anything we can do to boost delivery is extremely welcome," said the council's deputy housing leader Norman Work.
Several large residential projects are planned for the area, which is earmarked for major economic development in the Scottish government's west Edinburgh planning framework.
More than 300 homes are proposed at Ratho and Ratho station, 650 at West Craigs and another 500 on the former Continental Tyres factory in Newbridge.
However, Ryden property consultancy senior partner Roy Durie warned that the change could act as a barrier to development.
"It is absolutely the wrong time to be increasing the quota," he insisted. "The council should be reversing it, down to around ten per cent. It is effectively increasing the tax on landowners by 67 per cent."