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Environment / Climate change

What are "piggyback homes", and could they help ease London's housing crisis?

Another day, another document in our inbox containing increasingly hysterical suggestions for how we can hope to house the tens of thousands of people set to join the swelling ranks of London’s population every year. 

This offering comes from London Assembly Green member Darren Johnson, and contains several of the more standard suggestions, like building on car parks or community-led estate regeneration.

But one suggestion in particular caught our eye. Johnson proposes that we slap two stories on top of low-lying council blocks, in order to increase housing supply without making the building’s footprint any larger. He’s also given the concept an adorable name: “piggyback housing”. 

This is, of course, not a new idea. Johnson cites one particularly successful example in Hammersmith, the Ducane Housing Association. Here’s the before:

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Image: c/o Darren Johnson.

And the after:

Image: Google.

Of course, the developers have also jazzed up the building’s front and added some glass balconies – but the real story here is the two stories of housing perched on top of what was a relatively low-density block.

The financing of the project is pretty nifty, too: the housing association refurbished the 112 existing flats with the money earned by adding 44 new ones on top. There are also energy-saving benefits: a bigger block is more energy efficient, and better insulation can be added as part of the overall building upgrade. 

Johnson asked each London borough for an estimate of how many of these low-rise council blocks they had on the books. He figured out that, if one in three of these blocks were built on over the next decade, we could build 50,000 new homes and refurbish a further 300,000 in the process. This map shows the estimates for most boroughs:

Source: Darren Johnson. 

However, while this type of granular approach may be exactly what we need to squeeze the maximum housing out of our overloaded city, it also comes with its own problems. These projects would involve building, quite literally, on top of peoples’ current homes, presumably while they’re still living in them, as well as getting planning permission for intensive construction projects in the heart of active communities. This is probably one of those ideas that everyone likes in the abstract, but which hits real difficulties when you try to put it into practice in specific locations. 

But as we get more desperate, it’s something that’s worth keeping in mind, especially as these blocks come up for restoration anyway. With a bit of a push from councils and housing associations, we could essentially magic thousands of new homes out of thin air. Which would, frankly, be pretty great. 
This article is from the CityMetric archive: some formatting and images may not be present.