Build up or build out? How to tackle urban density

The Sapphire Tower: one of a new generation of residential towers proposed for Cardiff. Image: Nicholas Socrates Associates.

These days, we almost expect that any large-scale, big impact inner-city development will be a skyscraper. But for smaller cities in the UK these proposals can still appear as fairly extreme, and their approval contentious.

Take, for example, Cardiff, where a new 42-storey, 132m high building of affordable student accommodation is due to become Wales' new tallest building. At just under half the height of London’s Shard, the new building seems paltry when compared to the world’s skyscrapers – but developments like this are still big news for smaller cities.

This contention with skyscrapers is something that has been hashed out again and again in cities all over the world. But rather than focus on how high we are building new housing developments, or where they are situated, it is time that we looked at the big picture.

Under pressure

The pressure to accommodate the housing demand in the UK is enormous. However, the opportunity is there to look more at holistic solutions that achieve balanced outcomes. Unlike London, cities such as Cardiff, Manchester, Sheffield and Birmingham, to name a few, are not short of space; they still have capacity to accommodate the housing needed, while promoting happiness and well-being.


Building high rise residential units should be given a great deal of thought, even in those cases when the setting can accommodate them appropriately. There is sufficient scientific evidence of the negative health and social implications of dense living. Nottingham, for example, among other cities, is currently demolishing its iconic towers the Lenton flats, to give way to more positive residential alternatives.

The issue of urban density has been the subject of debate and research for decades, if not centuries. Humans can adapt to their environments but they do so at a cost – and a number of studies have highlighted the links between density and stress as well as other physical and psychological disorders.

High-rise living can be isolating, separating residents from daily urban life and the activities that take place on the streets. Up to three or four storeys, however, one can still comfortably walk down to the street. From a window, one can connect visually and feel part of the public scene. For this reason, many built environment professionals believe four storeys is the maximum acceptable building height to achieve a decent level of connection, protect health and deliver the right level of density at the same time.

Although it may then seem better for our health, low urban density and detached housing in “out of town” locations have been branded as one of the largest causes of greenhouse gases emissions because of car use. Lower densities also make it harder to develop a neighbourhood feeling: they increase travelling distances and may be more detrimental to farming and species preservation due to their potential expansion into agricultural land.

High or low

Despite the perks and pitfalls to both inner-city and low urban density living, people’s preference tends towards the latter. A study conducted in the US found that some people prefer low density suburbs because freestanding houses in open wide areas enhance their self-esteem and sense of ownership, and are convenient for driving and parking. Large UK housing developers have also found that this “American Dream” model also appeals to customers who want “character; neighbourhoods that feel like places with their own attractive identity”.

The major concern over increasing density is the public perception that privacy would be compromised and, although this issue can be resolved with intelligent design, traditional models remain largely the norm. Some aspects of design are essential to achieving a successful density level where people still find peace, a place where they can retreat from the stress of everyday life, a distinctive character, a sense of identity and community belonging.

But which approach should we choose – building up or moving out?

There is still debate about whether humans should live in lower density settlements or if the damage caused to the environment through this approach is simply too large. Unfortunately, both ends of the spectrum – suburbia and high rise – still dominate landscapes. And while people’s preferences justify low density, the argument that higher density better delivers sustainability is often misinterpreted and misused to justify development led by land value and to secure larger economic gains.

Some recent schemes – such as Accordia in Cambridge and Trent Basin in Nottingham Waterside – demonstrate that common ground can be achieved, delivering models of medium density with compact yet green living as a compromise, to create desirable urban environments while also delivering on sustainability.

However, prototypes like these often require innovative and creative funding mechanisms to make schemes feasible; and traditional residential development models are not currently sufficient to cope with all the pressures of the market and legislative frameworks. Until the planning, regulatory and financial mechanisms take the issues of environmental and social sustainability seriously, it is unlikely we will see positive changes in the design and delivery of residential schemes.

Perhaps a bigger effort is required from the built environment industry as a whole to find positive solutions to the issue of housing in UK urban areas. Skyscrapers should be more carefully considered for cities like Cardiff, where medium density developments are still viable and could provide the best of both worlds.The Conversation

Laura Alvarez is a lecturer in architectural technology at Nottingham Trent University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

How can cities become more bike friendly? The Netherlands offers useful lessons

(Aurore Belot/AFP via Getty Images)

It might seem like cycling is in the DNA of the Netherlands, a country where even the prime minister takes his bicycle to work. But the Dutch haven’t always lived as one with their bikes. In the Amsterdam of the early 1970s, cars were considered the wave of the future. They can be seen filling up squares and streets in historical photographs, and killed an average of over two Amsterdammers per week, including many children.

It is nothing more than an “accident of history” that the Netherlands embraced cycling, says Marco te Brömmelstoet, the director of the Urban Cycling Institute in Amsterdam and a man better known as the city’s cycling professor. Today’s bike rider’s paradise was created after parents and activists took to the streets to protest “child murder” by car. A Saudi oil embargo, rising gas prices, concerns about pollution and anger about the destruction of entire neighbourhoods to build motorways did the rest. 


Amsterdam, 1958. Not a cyclist's paradise. (Keystone/Getty Images)

What’s important about this history is that it can be replicated in other cities, too. Of course, the Netherlands has certain advantages – it’s flat as a pancake, for example. But in the eyes of traffic reformers, the rise of e-bikes (and even cargo bikes) means there’s no excuse for prioritising cars everywhere. 

So how can cities, flat or not, follow Amsterdam’s path to creating places where cycling is a pleasant, safe and common way to get around? The Dutch have some tips. 

Separate bikes from car traffic

Any city could start painting dedicated bike lanes on the streets. But in the Netherlands, those white marks indicating space for cyclists are considered just a minor first step. 

“A line on the road is not enough. Motorists will ignore it,” says Frans Jan van Rossem, a civil servant specialising in cycling policy in Utrecht. If other cities want their residents to choose bikes instead of cars when dodging pandemic-era public transport, protecting them from fast-moving car traffic must be the priority, Van Rossem says. 

The Dutch research institute CROW developed a widely praised design manual for bicycle infrastructure, full of tips for creating these protected lanes: A row of vertical white posts or a curb can serve as a physical separator, for example. Still, cyclists tend to feel safest in a "solitary" path, separated from the road by grass, trees, or an elevated concrete island. 

“The main bottleneck, the main reason why people don’t cycle, is that they don’t feel safe,” Van Rossem notes. “To start, construct separate paths.”

Turn those bike paths into a network

Many cities may have some bike lanes on some streets, but leave cyclists to roll the dice everywhere else. Will conditions still be safe when they turn left or right? Often they have to continue their way without any protected facilities for cyclists. 

“In many cases, cities take fast action, without thinking it through very well,” says Lucas Harms. He leads the Dutch Cycling Embassy, a partnership between the Dutch government and several companies, which promotes Dutch bike knowhow globally. “Don’t build small pieces of bike lane from nothing to nowhere. Think about a network of cycling infrastructure.” 

Utrecht aims to have cyclists within 200 to 300 metres of a connected path anywhere in the city, Van Rossem says. Avoid constructing those paths in sketchy industrial areas, he warns. “A connection through an unattractive area may be fast, but won’t be used a lot.”

Embrace the ‘fietsstraat’, a street where bikes come first


On some streets, drivers have to give up their privileges. (Rick Nederstigt/AFP via Getty Images)

A peculiar Dutch invention called "fietsstraat" (cycling street) holds strong potential for the rest of the world, Kevin Krizek says. He’s a transportation professor from Colorado who spent three years at Radboud University in Nijmegen. 

On cycling streets, cars are “guests”, restricted by a speed limit of 30 kilometres per hour. Drivers are not allowed to pass, so cyclists comfortably dominate the road. In the Netherlands the fietsstraat is usually paved with red asphalt, to resemble a bike path and notify drivers of their secondary status. But creating a cycling street can be easy. “All you need to do is put signs at intersections,” Krizek says. The effect is revolutionary in his view. Drivers have to give up their privileges, and cyclists can take the lead. 

Some Dutch traffic experts worry the cycling street won’t work if a city doesn’t also have a robust cycling culture. In the Netherlands, drivers are aware of the perils of urban cycling because they too use bicycles. Moreover, Dutch cities use sophisticated “circulation plans” to direct cars away from city centres and residential areas, onto a few main routes. 

Without “calming” traffic this way, the cycling street could be a step too far, Harms says. “In a city like New York, where all roads are equally accessible and full, it’s better to separate bicycles and cars,” he says.

Redesign intersections for cyclists' safety

If cyclists have to cross intersections “at the mercy of the Gods”, you’re not there yet, says Harms. When he travels abroad, he often finds clumsily designed crossings. As soon as cars turn, cyclists may fear for their lives. 

Harms recommends placing physical barriers between cars and bikes in places where they must cross. The Dutch build elevated islands to direct traffic into separate sections. The golden rule: cars wait behind bicycles. That way, drivers can see cyclists clearly at all times. Barriers also force Dutch cyclists to turn left in the safest way possible. They cross the street first and wait for their turn again before making their way left.

“You can create that with simple temporary measures,” Harms says. Planters work fine, for example. “They must be forgiving, though. When someone makes a mistake, you don’t want them to get seriously injured by a flower box’s sharp edge.”

Professor Krizek points out how the Dutch integrated cycling routes into roundabouts. Some are small; some are big and glorious, like the Hovenring between Eindhoven and Veldhoven, where cyclists take a futuristic-looking roundabout lifted above the highway. Most of those traffic circles move high volumes of cars and cyclists through intersections efficiently and safely. For a simpler solution, the Dutch manual suggests guiding cyclists to quieter streets – crossing a block up or down may be safer. “Nobody knows how to do intersections better than the Dutch,” says Krizek. 

Ban cars, or at least discourage them


A man rides down from a three-level bicycle parking garage near Amsterdam's main train station. (Timothy Clary/AFP via Getty Images)

The quickest, most affordable way to make a city more bikeable is to ban cars, says Ria Hilhorst, cycling policy advisor for the City of Amsterdam. It will make streets remarkably safe – and will most likely enrage a significant amount of people. 

Amsterdam doesn’t outlaw cars, but it does deliberately make their owners feel unwelcome in the historic city’s cramped streets. Paid parking is hugely effective, for example. Many car owners decide to avoid paying and use bicycles or public transportation for trips into the city. Utrecht, meanwhile, boasts the world’s largest bicycle parking garage, which provides a dizzying 12,500 parking spots.

To further discourage drivers from entering the city’s heart, Amsterdam will soon remove more than 10,000 car-parking spaces. Strategically placed barriers already make it impossible to cross Amsterdam efficiently by car. “In Amsterdam, it is faster to cross the city on a bike than by car,” Harms says. “That is the result of very conscious policy decisions.”

Communicate the benefits clearly

Shopkeepers always fear they will lose clients when their businesses won’t be directly accessible by car, but that’s a myth, says Harms. “A lot of research concludes that better access for pedestrians and cyclists, making a street more attractive, is an economic boost.”

Try replacing one parking space with a small park, he recommends, and residents will see how it improves their community. Home values will eventually rise in calmer, bike-friendlier neighbourhoods without through traffic, Van Rossem says. Fewer cars mean more room for green spaces, for example.

“I often miss the notion that cycling and walking can contribute a lot to the city. One of the greatest threats to public health is lack of exercise. A more walkable and bikeable city can be part of the solution,” says Ria Hilhorst. “But in many countries, cycling is seen as something for losers. I made it, so I have a car and I’m going to use it, is the idea. 

“Changing this requires political courage. Keep your back straight, and present a vision. What do you gain? Tranquility, fewer emissions, health benefits, traffic safety, less space occupied by vehicles.” 

Again, she points to Amsterdam’s history. “It is possible; we were a car city too.”

Karlijn van Houwelingen is a journalist based in New York City.