The London Housing Federation and London Councils published a report last week that found that the amount of homes with three or more bedrooms had almost halved in the last ten years. This has resulting in overcrowding in the capital with detrimental effects on children, and recommended that more family sized homes be built. However, Terry Fuller, chair of the Home Builders’ Federation’s affordable housing panel, said that many of the family homes (71% the affordable homes in London) were under occupied. “Why aren’t London councils sweating their assets better? There are plenty of family homes that are not used as well as they could be,” Fuller claimed that forcing developers to build larger homes would result in fewer affordable homes being built. “The greatest demand is from single people.” Perhaps the shift in housing size is merely a reflection of falling fertility rates across Europe. A closer examination of the data shows shrinking family size is a worldwide trend, so brilliantly revealed in an animated presentation delivered by Hans Rosling at TED (Technology Entertainment Design) earlier this year.

The links between family size, life expectancy, and prosperity seem pretty universal though the direction of causality is not so clearly revealed. In the last four years, the cost of raising a child in the UK has risen 28% bringing the national average to £180,000. The cost of housing is a significant factor in this increase however it is not just the size of the house that accounts for this extra expense. In the book, “The Two-Income Trap: Why Middle-Class Mothers and Fathers Are Going Broke“, Harvard law professor and bankruptcy expert, Elizabeth Warren reveals that in America “married couples with children are more than twice as likely to file for bankruptcy as their childless counterparts.” One reason for this was identified:

“families were swept up in a bidding war, competing furiously with one another for their most important possession: a house in a decent school district. As confidence in the school system crumbled, the bidding war for family housing intensified, and parents soon found themselves bidding up the price for other opportunities for their kids, such as a slot in a decent preschool or admission to a good college.”

Indeed, British parents are no strangers to the intense competition for places in good schools, and this explains why affordable family housing may go unused if they happen to be badly located.

As a consequence, the housing market will target more single people and childfree couples, further encouraging lower fertility. But is this really such a bad thing? In 2005, the world population exceeded 6.5 billion with each successive billion person increment taking a shorter and shorter time. The WWF estimates that we would need two planets to sustain our projected population in 2050. A major factor is our rapidly increasing carbon footprint, of which the general public is slowly becoming more aware thanks to the success of documentaries such as “An Inconvenient Truth” (DVD released just this week.) and “The Great Warming“. A less well publicised problem is the peaking of oil and gas production, which even the optimists say will occur by 2050.

Yet those calling for bigger homes seem to be projecting past social, economic and technological growth blindly into the future. Governments have been especially willing to gamble on future technology that promises to overcome barriers to growth, as demonstrated by recent support for research in nuclear fusion as a power source. However it is a risky proposition to base our family planning decisions on technologies that do not yet exist, and more so when they only solve part of the problem. Even those in the business of developing technology will be the first to admit the real world limitations to scalability. Last year, Gordon Moore made this comment in relation to his famous Moore’s Law:

“It can’t continue forever. The nature of exponentials is that you push them out and eventually disaster happens.”