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

Image: Mikhail Esteves via Flickr.

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:

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. 


Coming soon: CityMetric will relaunch as City Monitor, a new publication dedicated to the future of cities

Coming soon!

Later this month, CityMetric will be relaunching with an entirely new look and identity, as well as an expanded editorial mission. We’ll become City Monitor, a name that reflects both a ramping up of our ambitions as well as our membership in a network of like-minded publications coming soon from New Statesman Media Group. We can’t wait to share the new website with you, but in the meantime, here’s what CityMetric readers should know about what to expect from this exciting transition.  

Regular CityMetric readers may have already noticed a few changes around here since the spring. CityMetric’s beloved founding editor, Jonn Elledge, has moved on to some new adventures, and a new team has formed to take the site into the future. It’s led by yours truly – I’m Sommer Mathis, the editor-in-chief of City Monitor. Hello!

My background includes having served as the founding editor of CityLab, editor-in-chief of Atlas Obscura, and editor-in-chief of DCist, a local news publication in the District of Columbia. I’ve been reporting on and writing about cities in one way or another for the past 15 years. To me, there is no more important story in the world right now than how cities are changing and adapting to an increasingly challenging global landscape. The majority of the world’s population lives in cities, and if we’re ever going to be able to tackle the most pressing issues currently facing our planet – the climate emergency, rising inequality, the Covid-19 pandemic ­­­– cities are going to have to lead the way.

That’s why City Monitor is going to be a global publication dedicated to the future of cities everywhere – not just in the UK (nor for that matter just in the US, where I live). Our mission will be to help our readers, many of whom are in leadership positions around the globe, navigate how cities are changing and discover what’s next in the world of urban policy. We’ll do that through original reporting, expert opinion and most crucially, a data-driven approach that emphasises evidence and rigorous analysis. We want to arm local decision-makers and those they work in concert with – whether that’s elected officials, bureaucratic leaders, policy advocates, neighbourhood activists, academics and researchers, entrepreneurs, or plain-old engaged citizens – with real insights and potential answers to tough problems. Subjects we’ll cover include transportation, infrastructure, housing, urban design, public safety, the environment, the economy, and much more.

The City Monitor team is made up of some of the most experienced urban policy journalists in the world. Our managing editor is Adam Sneed, also a CityLab alum where he served as a senior associate editor. Before that he was a technology reporter at Politico. Allison Arieff is City Monitor’s senior editor. She was previously editorial director of the urban planning and policy think tank SPUR, as well as a contributing columnist for The New York Times. Staff writer Jake Blumgart most recently covered development, housing, and politics for WHYY, the local public radio station in Philadelphia. And our data reporter is Alexandra Kanik, whose previous roles include data reporting for Louisville Public Media in Kentucky and PublicSource in Pittsburgh, Pennsylvania.

Our team will continue to grow in the coming weeks, and we’ll also be collaborating closely with our editorial colleagues across New Statesman Media Group. In fact, we’re launching a whole network of new publications this fall, covering topics such as the clean energy transition, foreign direct investment, technology, banks and more. Many of these sectors will frequently overlap with our cities coverage, and a key part of our plan is make the most of the expertise that all of these newsrooms combined will bring to bear on our journalism.

City Monitor will go live later this month. In the meantime, please visit citymonitor.ai to sign up for our forthcoming email newsletter.

As for CityMetric, some of its archives have already been moved over to the new website, and the rest will follow not long after. If you’re looking for a favourite piece from CityMetric’s past, for a time you’ll still be able to find it here, but before long the whole archive will move over to City Monitor.

On behalf of the City Monitor team, I’m thrilled to invite you to come along for the ride at our forthcoming digs. You can already follow City Monitor on LinkedIn, and on Twitter, sign up or keep following our existing account, which will switch over to our new name shortly. If you’re interested in learning more about the potential for a commercial partnership with City Monitor, please get in touch with our director of partnerships, Joe Maughan.

I want to thank and congratulate Jonn Elledge on a brilliant run. Everything we do from here on out will be building on the legacy of his work, and the community that he built here at CityMetric. Cheers, Jonn!

In the meantime, stay tuned, and thank you from all of us for being a loyal CityMetric reader. We couldn’t have done any of this without you.

Sommer Mathis is editor-in-chief of City Monitor.