Tokyo has rightly been getting some plaudits for housebuilding of late, and this post brings together some stats that illustrate just how impressive its record is.

First, some definitions and context. The statistics in this post are all for the Tokyo Metropolis area, also known as Tokyo Prefecture, with a population of around 13.5 million as of 2015. This is just part of the Greater Tokyo urban area, which holds around 37.8 million people, but for the purpose of this post when I say ‘Tokyo’ I mean the Metropolis/Prefecture.

The data in this post come from three online collections: the Tokyo Statistical Yearbook, the Japan Housing and Land Survey tables and Historical Statistics of Japan. As data sources these are all the more useful for being extremely old-fashioned: data is presented in tables using the same variable names and layouts going back decades, arranged on sites that for the most part seem to have not been re-designed since the early 2000s at the latest. Long may that continue, because when combined with an awesome commitment to publishing statistics in English, the end result is an amazingly accessible trove of historic data, probably more than is available for any other city I’ve looked at including London.

It’s well known that Japan’s population is falling, but less so that Tokyo continues to grow, adding around 940,000 people (an extra 7.5%) between 2005 and 2015. That means Tokyo, like many big cities around the world, has the challenge of how to ensure there’s enough housing to go around. But unlike most big cities around the world, Tokyo is actually meeting that challenge.

Annual housebuilding statistics in Tokyo are expressed in terms of dwelling starts rather than completions. The chart below (compiled from various years of the Tokyo Statistical Yearbook) shows the trend in new dwelling starts in Tokyo between 1995 and 2015. Starts hit a peak of 192,000 in 2003 and a trough of 108,000 in 2009 but averaged 155,000 new homes over the two decades.

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New dwelling starts, Tokyo Prefecture 1995-2015
Year Starts
1995 155161
1996 164704
1997 154733
1998 149263
1999 147108
2000 167721
2001 159809
2002 174596
2003 192427
2004 188302
2005 186642
2006 186199
2007 137303
2008 157169
2009 108416
2010 119858
2011 130700
2012 140862
2013 144562
2014 142417
2015 141978

But that’s new supply in gross terms and everyone knows the Japanese demolish housing at a much higher rate than most countries, so what’s the net growth like? The chart below (from table 5 here) shows how the number of homes in Tokyo changed between 1963 and 2013 (based on the five-yearly Housing and Land Survey, the latest one of which was carried out in 2013). In just a fifty year period Tokyo’s housing stock nearly tripled in size, from 2.51 million homes in 1963 to 7.36 million in 2013.

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Dwelling stock, Tokyo Prefecture 1963-2013
1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013
2514000 3139380 3795600 4239200 4528200 4817600 5299500 5669500 6186000 6780500 7359400

Tokyo does demolish a lot of housing - between 2002 and 2011 there were 1.58 million starts but between 2003 and 2013 the stock grew by 1.17 million, so if we assume that it takes an average of two years from start to completion then it looks like 0.41 million homes were demolished in a decade, or about 7% of the 2003 stock. Put another way, roughly one home is demolished for every four new ones built. But the scale of construction still means that Tokyo’s housing stock is growing very fast - roughly 2% a year, about twice as fast as that of Paris, London or New York as the chart below shows.

World city housing growth chart, from the GLA’s Housing in London 2017 report

World city housing growth chart, from the GLA’s Housing in London 2017 report

In 1963 there were 2.69 million households in Tokyo, and by 2013 this had grown to 6.51 million. So while the number of households grew quickly, the number of homes grew faster, and Tokyo went from having a crude ‘housing deficit’ in 1963 to a ‘surplus’ in 1973, and an even bigger surplus every year after that. By 2013 there were 849,000 more homes than households.

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Dwelling deficit/surplus, Tokyo Prefecture 1963-2013
1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013
-178000 -39940 131200 324200 433500 457500 579900 664700 699200 795100 849300

What strikes me about this chart is that at every point after 1968 Tokyo had (a) more than enough housing to go around (by this measure, anyway) and (b) more than it had ever had before. It is often said that by those criteria the UK should stop focusing on new trying to increase new supply and should instead focus on a better distribution of its existing housing. But Tokyo illustrates another strategy: keep building more and more housing, far past the point of mere sufficiency and into the realm of abundance.

The next chart shows the change in the type of dwellings in Tokyo between 1978 (the furthest back the data goes) and 2013. The fastest growth has been in apartments, particularly the tallest ones (six storeys or more). In 1978 there were 823,000 homes in Tokyo in apartment buildings of 3 or more storeys. 25 years later there were 3.6 million. Over the same period the number of houses grew slightly while the number of low-rise apartments fell. All of this is consistent with a pattern of housing growth achieved primarily through densification rather than sprawl.

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Dwelling type and height, Tokyo Prefecture 1978-2013
Year Detached houses / tenements 1-2 storey apartments 3-5 storey apartments 6+ storey apartments Others
1978 1674000 1272200 543400 279700 42700
1983 1660300 1156700 726200 442500 43000
1988 1618300 1128000 953200 566300 39200
1993 1571700 1118800 1235100 690100 44600
1998 1610200 1043300 1396700 849200 42200
2003 1709800 967900 1506300 1223500 26700
2008 1780200 952400 1619700 1562800 24900
2013 1915400 952300 1695900 1881500 27500

That’s backed up by data on land use, which indicates that the acreage devoted to housing in Tokyo grew by around 1.5% between 2006 and 2011, whereas the number of homes grew by 9.2%. On average there are around 110 dwellings per hectare of residential land in Tokyo, compared to roughly 60 in London as of 2005 (the last time similar land use statistics were collected).

Really fast densification in an already built-up area like Tokyo can only be achieved through demolition and redevelopment, and we’ve already seen that around one existing home is demolished for every four new ones. The next chart shows how that trend has affected the age of profile of Tokyo’s housing stock over time. For obvious reasons there aren’t many dwellings in Tokyo dating from earlier than 1950, but even the stock of homes built in the 1950s and 1960s is dwindling fast: in 1998 there were 856,000 homes originally built between 1951 and 1970, but only 15 years later in 2013 this had fallen to 451,000. Replacing swathes of old housing with taller, denser new housing is what enables Tokyo to grow its housing stock so fast.

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Dwelling age (excluding unknowns), Tokyo Prefecture 1998-2013
Year 1950 or earlier 1951 ~ 1960 1961 ~ 1970 1971 ~ 1980 1981 ~ 1990 1991 ~ 1995 1996 ~ 2000 2001 or later
1998 81200 201600 654600 1169500 1493700 696800 347500 0
2003 75900 138800 515300 951000 1319400 650000 778800 386400
2008 65500 103900 442300 897400 1128700 544700 737300 1141200
2013 58200 73200 377900 877700 1118800 577700 640900 1821100

What does all this new construction mean for the amount of housing space available? Tokyo has a reputation for tiny apartments, and at 64m2 its average dwelling size is indeed smaller than what most Westerners would be used to, although it has risen over time.

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Average floorspace (m2) per dwelling, Tokyo 1963-2013
1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013
54.41 50.21 52.34 54.48 58.02 60.27 62.05 61.94 64.48 63.94 64.48

The average size of new homes in Tokyo is very similar, at 65m2 (down from around 80m2 in the late 1990s).

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Average size of new dwellings started, Tokyo Prefecture 1995-2015
Year Average.floorspace
1995 78.33
1996 78.73
1997 78.80
1998 78.17
1999 78.59
2000 80.63
2001 78.41
2002 75.57
2003 72.63
2004 71.94
2005 69.47
2006 67.16
2007 70.36
2008 67.66
2009 68.52
2010 72.67
2011 72.55
2012 71.30
2013 69.75
2014 68.05
2015 65.15

But what these figures on average dwelling size don’t tell you is that the average Tokyo resident has far more space today than they did fifty years ago. The reason is that the average number of people in a Tokyo household has plummeted over this period, from 3.6 in 1963 to 2.0 in 2013. Of course, this could only happen because there was so much housing available for people to move into. When there isn’t enough housing then you get the opposite effect - of multiple unrelated people living together, and rising household sizes. London’s a good example of this.

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Average household size in Tokyo Prefecture, 1963-2013
1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013
3.63 3.34 3.04 2.9 2.79 2.67 2.44 2.33 2.21 2.12 2.01

When you combine the average floorspace per home and the average number of people per household you get the below trend in average floorspace per person (this shows the space in occupied homes only - if you took vacant homes into account it would be much higher). The amount of space per person saw a remarkable increase from 15m2 in 1963 to 32m2 in 2013. Londoners have a similar amount of space per person on average today (assuming similar methodologies for measuring floorspace - there’s not enough detail in the Tokyo stats to tell), but in stark contrast to Tokyo there has been little or no increase in London in around 20 years (according to this article, which in classic UK-housing-discourse style seems to suggest that it’s evidence against a housing shortage).

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Average floorspace per person in Tokyo Prefecture, 1963-2013
1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013
15 15.04 17.22 18.81 20.77 22.59 25.4 26.64 29.2 30.15 32.03

So how come Tokyo is so good at building housing? That’s a long story in itself, but this Robin Harding article in the FT is a good place to start, and if you want to dig into the academic literature try here, here and here. In short, Japan has a relatively simple and unambiguous zoning code, one which the national government has repeatedly adjusted in order to allow for more housing growth in Tokyo. That has been done in the face of opposition at neighbourhood and even city level, opposition that in countries which have devolved land use decisions to a local level would be enough to stop densification or at least divert it to poorer areas. What you might call the ‘supersidiarity’ of Japan’s approach to housing policy is therefore quite progressive, as well as being extremely effective in getting housing built.