The report, by economics consultancy ChamberlainWalker on behalf of housebuilder Barratt, found that post-planning permission development timescales "have increased markedly" in recent years.
On sites of 20 homes or more, it says, it now takes "at least 4.0 years on average from the grant of detailed planning permission to site completion".
This compares to a 2013 Local Government Association study that estimated that, across all site sizes, it took an average of 1.7 years to navigate land through the post-planning permission phase, a figure that rose to 3.2 years for sites of 100 homes or more.
According to the Barratt report, using 2017 data from construction consultancy Barbour ABI, the longer planning permission to site start timescale "is likely to be the result of an increased burden of pre-commencement conditions" attached to planning permissions.
Meanwhile, the report puts the longer construction phase down to "an increased reliance in England for housing delivery on ‘large sites’ that take longer to build out".
The report also examines how much of a land bank – their supply of development land –housebuilders need compared to their output of homes "to ensure a steady or growing level of production".
According to the report, the Department for Communities and Local Government estimates that ten to 20 per cent of planning permissions don’t make it to a start before they lapse.
"This means that the permissioned land bank needs to be much bigger than the permissioned pipeline of four years to account for those consents that don’t make it through," says the Barratt document.
It calculates that a stock of 1.25 million planning permissions, of which one million would be detailed, would be needed to secure 250,000 home completions a year. This compares to a current stock of around 800,000 permissions, of which 700,000 are detailed, suggesting a shortfall of about 450,000 permissions.
Last year in England, planning permission was granted for 262,000 new homes but only 142,000 got under way, the report adds.
The report can be read here.
Note: the introduction to this story was changed at 4pm on Tuesday 24 October to make it clear that the estimated period of time from planning permission to housing completion is four years, according to the report. It is not that housebuilders are "having to wait" this length of time, as previously stated.