Modern cities are forcing skyscrapers to evolve

Chicago, home of the skyscraper. Image: Wikimedia Commons.

Slick, glassy skyscrapers cast their shadows over the streets and spaces of cities all over the world. These behemoths are notoriously inefficient: glass exteriors trap the sun’s rays during summer and haemorrhage heat throughout the winter, requiring year-round air conditioning and climate control. Dark interiors necessitate vast arrays of bright lighting, while hundreds of computers whirr 24 hours, consuming even more electricity.

At a time when energy efficiency is a matter of global significance, it’s worth considering how these dark, glass giants came to dominate the urban landscape – and how we can build to fix these flaws in the future. In fact, the modern skyscraper emerged from an architectural evolution, which started with the construction of Chicago’s tall office buildings during the 1880s.

UN building in New York. Image: United Nations Photo/Flickr/creative commons.

The iconic “International Style” skyscraper – a prismatic glass surface wrapped around a central service core – was envisioned during the 1920s and 1930s, by German architects who fled to America from Germany – notably Walter Gropius and Mies van der Rohe. It was first built in America during the 1950s – the UN Building (1952), Lever House (1954) and the Seagram Tower (1958) of New York are seminal dark glass-walled office buildings, which spawned countless imitators worldwide, until the 1980s.

21st-century style icon

Although the limitations of the International Style became obvious in the late 20th century, when governments implemented stricter energy standards, glass still predominates as we approach 2020. Today’s office skyscrapers, particularly those seen in business districts in the Middle and Far East, use double skin facades – an outer skin of glass wrapping around the real building within – to maintain glassiness and permit daylight, while improving insulation and resistance to solar gain.

Energy-saving features, such as efficient lighting and energy-regenerating elevators are now normal. Trigeneration (heating-cooling-power plants) hum efficiently in the basements, while solar shading and openable windows are sometimes used to reduce air conditioning loads. Green planting is appearing in lobbies and sky gardens, fed by captured rainwater.

The way that cities and workplaces are developing demands even greater change. In an age of rising urbanisation, the American idyll of a compact high-rise business district, surrounded by a vast residential suburban sprawl served by freeways and shopping malls is simply not compatible with the land resources, population, energy and transport requirements of 21st-century cities.

To cope with the pressures of dynamic mass-transit systems and rising land values, urban citizens must grow accustomed to living – as well as working – in high-rise developments, clustered around key transport nodes.

La Defénse, Paris’ high-rise quarter. Image: IceNineJon/Flickr/creative commons.

Different cities are responding to these challenges in different ways. London has a policy of clustering tall buildings in groups around key rail stations, maintaining clear view lines in between. These clusters become magnets for additional office and residential towers.

Paris excludes skyscrapers from its centre altogether, limiting them to districts such as La Defense, at the outskirts of the city. Meanwhile, China has built eerie “ghost cities”: entire districts of high-rise buildings, constructed prior to the population moving in.


Mixed-use futures

The way that people use skyscrapers is also changing. For one thing, the internet has reduced the demand for conventional offices. The current trend is for large trading floors, or landscaped office interiors with multi-screen workstations, hot-desking – and meetings held in daylit break-out spaces. There is less need for huge walls of glass. For daylight, there is a return to large glazed windows set in an insulating wall.

Among small businesses, there’s a demand for “incubator” offices, often in converted warehouses. Employees can work from home using video conferencing and virtual networks. Indeed, many redundant office buildings of the 20th century are already converted to residential uses, such as Metro Central and the Southbank Tower in London.

Another major trend is the mixed-use skyscraper, where parking, dining, transport, hotel, offices, social sky-parks, residences, colleges, health and leisure centres are stacked vertically into one single footprint, with food, beverage and retail outlets at ground level. This is becoming the norm in the newest tall buildings, especially in Japan and China.

Mixed-use towers make the best use of land and are more resilient to economic shocks because the rental income comes from lots of different sources – and the flows of people are balanced, instead of peaking twice daily. The idea started in Chicago in 1969, developed in China, and now appears in most global mega-cities. Examples include the London Shard, the Shanghai tower, PS100 (Singapore), Hysan Place (Hong Kong) and the proposed development at 470 11th Ave (New York).

Shanghai Tower. Image: andymiccone/Flickr/creative commons.

New techniques of construction such as ultra-stiff service cores, continuous concrete casting, outriggers, lattice frames and seismic damping systems have made it possible to build very tall. Dubai’s Burj Khalifa exceeds 800 metres, and Jeddah’s Kingdom Tower will reach to 1,000 metres when it’s finished.

The fifth generation emerges

Yet as we look forwards, the most significant trend will not be extravagant height – but energy efficiency. The skyscrapers of the future are those that architects call “fifth generation”, which aim for a carbon-neutral footprint, such as Melbourne’s Ch3, One Bligh Street, Sydney and One Angel Square, Manchester.

These exceptional new towers include a variety of eco-friendly innovations, such as renewable energy generation, solar shading and double-skin facades with natural ventilation. They will also feature greater thermal mass, landscaped atriums, underground heat storage, water catchment, recycling, linear induction elevators, as well as vertical urban farms, green planting, and facades and roofs that generate electricity.

The future cannot be found in a small number of freakishly tall designs. Rather, it is in the vast number of efficient, versatile skyscrapers, which will be essential to cope with growing urban populations and keep cities running.The Conversation

David Nicholson-Cole is assistant professor in architecture at the University of Nottingham.

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

 
 
 
 

Was the decline in Liverpool’s historic population really that unusual?

A view of Liverpool from Birkenhead. Image: Getty.

It is often reported that Liverpool’s population halved after the 1930s. But is this true? Or is it a myth?

Often, it’s simply assumed that it’s true. The end. Indeed, proud Londoner Lord Adonis – a leading proponent of the Liverpool-bypassing High Speed 2 railway, current chair of the National Infrastructure Commission, and generally a very influential person – stood on the stairs in Liverpool Town Hall in 2011 and said:

“The population of Liverpool has nearly halved in the last 50 years.”

This raises two questions. Firstly, did the population of the City of Liverpool really nearly halve in the 50 year period to 2011? That’s easy to check using this University of Portsmouth website – so I did just that (even though I knew he was wrong anyway). In 2011, the population of the City of Liverpool was 466,415. Fifty years earlier, in 1961, it was 737,637, which equates to a 37 per cent drop. Oops!

In fact, the City of Liverpool’s peak population was recorded in the 1931 Census as 846,302. Its lowest subsequent figure was recorded in the 2001 Census as 439,428 – which represents a 48 per cent decline from the peak population, over a 70 year period.

Compare this to the population figures for the similarly sized City of Manchester. Its peak population also recorded in the 1931 Census as 748,729, and its lowest subsequent figure was also recorded in the 2001 Census, as 392,830. This also represents a 48 per cent decline from the peak population, over the same 70 year period.

So, as can be seen here, Liverpool is not a special case at all. Which makes me wonder why it is often singled out or portrayed as exceptional in this regard, in the media and, indeed, by some badly briefed politicians. Even London has a similar story to tell, and it is told rather well in this recent article by a Londoner, for the Museum of London. (Editor’s note: It’s one of mine.)

This leads me onto the second question: where have all those people gone: London? The Moon? Mars?

Well, it turns out that the answer is bit boring and obvious actually: after World War 2, lots of people moved to the suburbs. You know: cars, commuter trains, slum clearance, the Blitz, all that stuff. In other words, Liverpool is just like many other places: after the war, this country experienced a depopulation bonanza.


So what form did this movement to the suburbs take, as far as Liverpool was concerned? Well, people moved and were moved to the suburbs of Greater Liverpool, in what are now the outer boroughs of the city region: Halton, Knowsley, St Helens, Sefton, Wirral. Others moved further, to Cheshire West & Chester, West Lancashire, Warrington, even nearby North Wales, as previously discussed here.

In common with many cities, indeed, Liverpool City Council actually built and owned large several ‘New Town’ council estates, to which they moved tens of thousands of people to from Liverpool’s inner districts: Winsford in Cheshire West (where comedian John Bishop grew up), Runcorn in Halton (where comedian John Bishop also grew up), Skelmersdale in West Lancashire, Kirkby in Knowsley. There is nothing unique or sinister here about Liverpool (apart from comedian John Bishop). This was common practice across the country – Indeed, it was central government policy – and resulted in about 160,000 people being ‘removed’ from the Liverpool local authority area.

Many other people also moved to the nearby suburbs of Greater Liverpool to private housing – another trend reflected across the country. It’s worth acknowledging, however, that cities across the world are subject to a level of ‘churn’ in population, whereby many people move out and many people move in, over time, too.

So how did those prominent images of derelict streets in the inner-city part of the City of Liverpool local authority area come about? For that, you have to blame the last Labour government’s over-zealous ‘Housing Market Renewal Initiative’ (HMRI) disaster – and the over enthusiastic participation of the then-Lib Dem controlled city council. On the promise of ‘free’ money from central government, the latter removed hundreds of people from their homes with a view to demolishing the Victorian terraces, and building new replacements. Many of these houses, in truth, were already fully modernised, owner-occupied houses within viable and longstanding communities, as can be seen here in Voelas Street, one of the famous Welsh Streets of Liverpool:

Voelas Street before HMRI implementation. Image: WelshStreets.co.uk.

The same picture after HMRI implementation Image: WelshStreets.co.uk. 

Nonetheless: the council bought the houses and ‘tinned them up’ ready for demolition. Then the coalition Conservative/Lib Dem government, elected in 2010, pulled the plug on the scheme. 

Fast forward to 2017 and many of the condemned houses have been renovated, in a process which is still ongoing. These are over-subscribed when they come to market, suggesting that the idea was never appropriate for Liverpool on that scale. 

At any rate, it turns out that the Liverpool metropolitan population is pretty much the same as it was at its peak in 1931 (depending where the local borough boundaries are arbitrarily drawn). It just begs the question: why are well educated and supposedly clever people misrepresenting the Liverpool metropolis, in particular, in this way so often? Surely they aren’t stupid are they?


And why are some people so determined to always isolate the City of Liverpool from its hinterland, while London is always described in terms of its whole urban area? It just confuses and undermines what would otherwise often be worthwhile comparisons and discussions. Or, to put it another way: “never, ever, compare apples with larger urban zones”.

In a recent Channel 4 documentary, for example, the well-known and respected journalist Michael Burke directly compared the forecast population growths, by 2039, of the City of Liverpool single local authority area against that of the combined 33 local authority areas of Greater London: 42,722 versus 2.187,708. I mean, what bizarre point is such an inappropriate comparison even trying to make? It is like comparing the projected growth of a normal sized-person’s head with the projected growth of the whole of an obese person, over a protracted period.

Having said all that, there is an important sensible conversation to be had as to why the populations of the Greater Liverpool metropolis and others haven’t grown as fast as maybe should have been the case, whilst, in recent times, the Greater London population has been burgeoning. But constantly pitching it as some sort of rare local apocalypse helps no one.

Dave Mail has declared himself CityMetric’s Liverpool City Region correspondent. He will be updating us on the brave new world of Liverpool City Region, mostly monthly, in ‘E-mail from Liverpool City Region’ and he is on twitter @davemail2017.