PLANNING decisions on major housebuilding projects are taking more than a year to be approved, provoking "outrage" in the construction industry and prompting the Government to pledge action on poor performance by local authorities.

Despite reforms to planning legislation to streamline the process, new official statistics show decisions on major housing applications are still taking an average of nearly 77 weeks – over a year longer than the 16-week timescale supposedly laid down in law.

Homes for Scotland, the body representing housebuilders, condemned the poor performance. Allan Lundmark, its director of planning, said: "Scotland is in the midst of its worst housing crisis since the Second World War – with only 15,000 new homes built in 2011 despite 160,000 people being on housing waiting lists, households growing at a rate of more than 21,000 per annum and our population being at its highest ever level.

"Thousands of new, warm, sustainable homes are desperately needed. Scotland's homebuilders stand ready to provide them, but – facing the worst market conditions in living memory – these figures support our own internal research and confirm the planning system is strangling rather than facilitating what little investment is available."

Mr Lundmark added: "These statistics also call into serious question the Scottish Government's ambition in introducing higher fees for a system that is clearly not performing and shows no sign of improving."

Planning Minister Derek Mackay said there could be no increase in planning application fees unless there was an "inextricable link to improved performance". He added: "The Scottish Government will take action on poor performance when it occurs and will investigate the reasons for lengthy delays, as now shown up by this new format of statistics. We will work to ensure unnecessary delays are removed from the planning system."

Graeme Brown, director of Shelter Scotland, said: "In the autumn budget the Scottish Government committed an extra £45 million to building new affordable homes this year. But if planning decisions take so long, it is unlikely this funding will achieve its aim of a quick – if small – reduction in waiting lists.

"Shelter Scotland believes at least 10,000 new socially rented homes a year are needed to begin tackling Scotland's housing crisis. Investment and planning must work together to get Scotland building again and bring hope to the thousands of families and individuals trapped on housing waiting lists."

Labour's Sarah Boyack said: "These are massive delays when we desperately need new houses and the jobs to build them."

Scottish Conservative housing spokesman Alex Johnstone urged help for "a vital industry that is struggling".