We may be getting better at building more houses but unfortunately we’re not very good at counting them.
In August, the housing minister was citing the latest DCLG New Build statistics as proof that the country is building again. Completions across England had apparently reached 153,000 in the year to June 2017, “the highest level since 2008”. On this basis, the minister may be pleasantly surprised and slightly confused when he reads the DCLG’s Net Supply release in November and finds out that housebuilding completions had already reached 155,000 in 2014-15, and are actually much higher.
The housing minister can perhaps be forgiven some excitement over the first release of housebuilding statistics during his tenure. Based on the average tenure of previous housing ministers, he’s probably only got another three or four to look forward to. However, despite some allowance for over-excitement, it is irresponsible for the housing minister to be quoting the New Build statistics as absolute measures of housebuilding as they under-count the number of new homes actually being built.
It is particularly irresponsible because DCLG are well aware that there are issues with the New Build statistics. In the introduction to their New Build statistical release they suggest the New Build figures should only be “regarded as a leading indicator of overall housing supply”, and instead the Net Supply release “is the primary and most comprehensive measure of housing supply”.
The scale of the under-count is apparent when comparing the New Build data to the more comprehensive Net Supply release. While the Net Supply release includes conversions, changes of use, and demolitions to calculate the net change in dwellings, it also includes a more comprehensive measure of housebuilding.
The latest available Net Supply data for 2015-16 recorded 164,000 housebuilding completions across England compared to only 140,000 completions recorded in the New Build data. That suggests the New Build release is currently missing around 15 per cent of the housebuilding market.
Beyond the widespread confusion created by the publication of different housebuilding numbers, this issue has important consequences for policy makers. Our failure to accurately measure housebuilding and our limited understanding of who is doing the building make it very difficult to accurately assess the success or failure of existing policies and identify new ones that could increase new supply.
The exact reasons for the under-count are not confirmed but it appears to be linked to the falling market share of the largest provider of warranties on new homes. The National Home Building Council (NHBC) provides a substantial share of the data used to create the New Build statistics, and it’s been widely assumed that they have a market share of around 80 per cent. Based on an assumed market share, the NHBC data is grossed up to provide a measure for the whole market alongside other sources of building control inspection data.
However, recent years have seen a broader range of groups delivering new homes. Volume housebuilders still deliver the majority of new homes but there has been an increase in activity by SME housebuilders, high-density luxury developers, build-to-rent investors, and housing associations. For some of the firms and organisations in these groups, an NHBC warranty may be too expensive or not attractive compared to the alternatives. NHBC’s market share has probably fallen over this period.
A fall in NHBC’s market share is apparently confirmed by the request for a review of its market undertakings from the Competition & Markets Authority (CMA). Although most of the market share data published by the NHBC and the CMA in the review is confidential, there is an interesting finding in the CMA’s provisional decision (paragraph 4.32). Using new home data from nine warranty providers including NHBC, the CMA estimated the NHBC market share at around 70 per cent.
If, instead of grossing up the NHBC data by 80 per cent market share, we use 70 per cent then we would expect the DCLG New Supply data to be around 14 per cent higher (0.8/0.7). That difference would account for nearly all of the shortfall in the New Build completions when compared to the Net Supply housebuilding data. While there may be other factors causing the under-count, it would appear that this market share issue is the most significant factor.
It would be great if we had an accurate and regularly updated measure of housebuilding, but it turns out that counting houses is actually quite difficult. The Net Supply data is far from perfect, and it’s only released once a year with a substantial delay but it’s the best we currently have.
Meanwhile, in Ireland they’ve had the opposite problem, with an over-count of new homes. Official completions data uses electricity connections – but it turned out that the actual number of new build completions between 2011 and 2015 was 42 per cent lower than the official figures due to a large number of re-connections.
Until we see a substantial re-working of the DCLG’s New Build statistics, it appears the best option is to assess the full range of available indicators that cover both housebuilding and total supply. However, perhaps the biggest frustration is that DCLG are aware of the issues with the New Build statistics yet we still see quarterly political point scoring based on these flawed data. Given the complexities of the housing market, it is only once we move past this short-term politicking that we have any hope of solving the crisis.