The delivery test, which was introduced in July's revised National Planning Policy Framework (NPPF), aims to ensure that local authorities actually build enough homes as well as plan for them.
It works by imposing various sanctions on authorities who fail to deliver over the previous three years against their housing requirement.
Authorities who deliver less than 95 per cent of their requirement must devise an action plan outlining how they will boost home-building in their area. Those who deliver less than 85 per cent must also identify a "buffer" of 20 per cent more housing sites to add to their land supply position, while those delivering less than 25 per cent face the NPPF's presumption in favour of sustainable development.
The government will formally publish its first delivery test results, for the three years from 2015 to 2018, before the end of this month.
However, research by Planning (see analysis below) using the government's latest 2017/18 net housing additions figures found that 120 councils, or 37 per cent, are set to face a sanction under the test (see list at end of article).
Our findings, in line with the higher 2017/18 net housing addition figures, show an overall improvement in authorities’ position under the test when compared with a previous Planning analysis in April, which looked at authorities’ 2014-17 delivery rates.
Following the government's delivery test criteria, we compared net additions in 2015-18 to each councils’ housing requirement over the same period, which is based on either an up-to-date local plan target or the household projections, whichever was the lower.
We found that no authorities are set to fail on the 25 per cent threshold and face the most severe penalty.
However, 37 per cent are likely to have to produce an action plan, while 30 per cent would be required to have a 20 per cent buffer in their housing land supply.
Almost two-thirds of councils – 63 per cent – are above the 95 per cent threshold and face no HDT sanction, a rise from 54 per cent compared with our April analysis.
Next year, the delivery test threshold for the presumption penalty will be raised to 45 per cent of delivery against the target, and in 2020 to 75 per cent.
Planning’s research found that nine councils had a delivery rate of under 45 per cent in 2015-18, while 74 - just over a fifth - were under 75 per cent.
In our research, to produce a housing requirement figure, we used analysis by the Planning Advisory Service (PAS) of household projections, along with local authorities' latest local plan data.
CORRECTION: This story was updated at 9am on Tuesday 27 November to rectify an error in the calculations. The original article incorrectly included Dartford, Crawley and Dudley councils in the list of authorities whose housing delivery rates in 2015-18 were under 95 per cent. In fact, all of them had rates over 95 per cent, according to our calculations. Dartford's housing delivery rate should be 180 per cent, not 57 per cent; Crawley's should be 149 per cent, not 63 per cent; while Dudley's should be 101 per cent, not 89 per cent. We apologise for any confusion caused.
In addition, the overall figure for the number of councils facing the action plan requirement is 120, not 123, while the number having to include a 20 per cent buffer in their housing land supply is 99, not 101.