Garden cities: lighter, faster, cheaper
November 09, 2017
November 09, 2017
Can we realise the dream of a cleaner, greener, and more economical garden city
Let me transport you to an industry a bit more relaxing than planning and infrastructure development. It’s a bit more chilled out. Less competitive. Let’s say it’s Formula 1 motor racing. And you have your dream job of designing the winning car. You’re wondering how to achieve better results … and then you have a stroke of inspiration.
It occurs to you that if you shave weight off the chassis and make the components lighter, your car goes faster. Less weight means you can redesign the suspension. Again, you’ve cut weight, so your car goes faster. Because the car is lighter, you need lighter brakes, and the weight saving makes your car goes faster. And so on. You realise with mounting satisfaction that you’ve locked yourself into a virtuous cycle. A sense of confidence and professional mastery suffuses your body. Well done you.
A nice daydream, for sure. But maybe we need a piece of that daydream for the garden city programme. At the start of this series we identified affordability—that is, being able to afford to live near where you work—as one of the key challenges that garden cities have got to help us solve. And it might just be that, if we are smart, we can use some upcoming innovations to help us make the whole programme lighter, faster and cheaper—but still deliver superb outcomes.
First up, land use. There’s a common misconception that a garden city is low density, but that’s not really right. (It is about land value capture, but that is a different story). The point is that we’ve got to use land efficiently. Newhall in Harlow is a great example of what can be achieved. The courtyard house typology is the main innovation, using square plots rather than the traditional rectangle. That gets the development to 52 dwellings/ha using a built form that looks a lot like a detached home. It doesn’t feel cramped. More public open space can be created using the land savings. And the higher density feeds back into transport infrastructure savings, given that distances are shorter and public transport is more viable.
That’s an obvious enough starting point. But it kick-starts our virtuous cycle. We keep it going by taking the flab out of transport infrastructure. How? Professor Peter Jones at UCL has a convincing answer. Jones has pointed out that we’re still in the game of predicting and providing: predicting transport demand using modelling, and then trying to provide the infrastructure the models say is needed. The snag is that we’re no good at predicting: past models have consistently over-estimated demand. Nor are we any good at providing: we usually run out of money and political support before we get close. And even where we do manage to “provide,” we never go back to check if the infrastructure is being used by those it was intended to facilitate—or if it has simply been clogged up by people making unnecessary journeys. The whole thing is a busted flush, says Jones, and that’s only going to get more obvious in an environment of continuing public sector austerity and radical uncertainty about the effects of technology on transport demand and supply.
Sounds bad? It isn’t: it’s a huge opportunity. Instead of predicting and providing, we need to start in a different place. We need to work out what society we want to live in, and build the connectivity that delivers that vision (think healthy, socially cohesive, compact, local). Seen that way, we get a radical connectivity rethink—and could dramatically cut costs. That bypass might no longer be needed. Big junction? No thanks. A sea of parking in front of every building? Not in a world of driverless cars. And could the 11m wide estate road we now think we need be reduced to something more akin to a rural lane, as long as we had a decent cycle route? Quite possibly, yes. (In that environment, the kids might even start to play out again).
Our garden city is already starting to feel quicker to build, nicer to be in, more sociable, and more affordable. There is no need to stop here. We can get more agile on building technologies. The point has been made elsewhere that if we made cars the same way we made houses, we’d deliver a bag of parts to the owner’s driveway, and then bolt together the whole thing in the customer’s garage (except that would be silly). We need to bring housing into the modern era: when modern methods of construction get to scale, they could dramatically cut housing build costs whilst boosting quality.
Then, we know that new technology for householders can also further offset costs. Tesla will sell you solar roof tiles which form part of the built fabric of the house. It’s cheaper because you don’t need a roof and solar panels: they are one and the same thing. You install a powerwall that will allow you to store the resulting energy. Householders can sell it back to the grid, and make a few quid. This isn’t a thing you do in five years’ time. You can buy this stuff today.
At this point, you’re really starting to roll. If you’ve got solar roofs and powerwalls, do you need gas grid connections? No: you save the money, and don’t even bother to install them. (The grid will be decarbonised, with a nuclear base load). And if we’re not doing gas, we can also strip out some other costs too. Combined heat and power systems are looking pretty questionable in terms of carbon abatement costs and air quality. Take them out. Whilst you’re at it, if you insulate houses properly you don’t need a central heating system: certainly in flats, you could get away with a couple of electric wall heaters (nip along to Argos—they’re thirty quid each). There’s a couple of thousand pounds saved per home.
Happier, cleaner, quieter, more sociable—as well as more affordable. We think that the success of garden cities is going to be about getting this virtuous cycle really starting to spin. Partner it up with the big one—land value capture—and we’ll have a revolution.
Originally published by PBA, now Stantec.