Glass skyscrapers are an environment disaster that could have been avoided

3 World Trade Centre, New York City. Image: Getty.

New York Mayor Bill de Blasio has declared that skyscrapers made of glass and steel “have no place in our city or our Earth anymore”. He argued that their energy inefficient design contributes to global warming and insisted that his administration would restrict glassy high-rise developments in the city.

Glass has always been an unlikely material for large buildings, because of how difficult it becomes to control temperature and glare indoors. In fact, the use of fully glazed exteriors only became possible with advances in air conditioning technology and access to cheap and abundant energy, which came about in the mid-20th century. And studies suggest that on average, carbon emissions from air conditioned offices are 60 per cent higher than those from offices with natural or mechanical ventilation.

As part of my research into sustainable architecture, I have examined the use of glass in buildings throughout history. Above all, one thing is clear: if architects had paid more attention to the difficulties of building with glass, the great environmental damage wrought by modern glass skyscrapers could have been avoided.

Heat and glare

The United Nations Secretariat in New York, constructed between 1947 and 1952, was the earliest example of a fully air conditioned tower with a glass curtain wall – followed shortly afterwards by Lever House on Park Avenue. Air conditioning enabled the classic glass skyscraper to become a model for high rise office developments in cities across the world – even hot places such as Dubai and Sydney.

The UN Secretariat building. Image: United Nations Photo/Flickr/creative commons.

Yet as far back as the 19th century, horticulturists in Europe intimately understood how difficult it is to keep the temperature stable inside glass structures – the massive hot houses they built to host their collections. They wanted to maintain the hot environment needed to sustain exotic plants, and devised a large repertoire of technical solutions to do so.

Early central heating systems, which made use of steam or hot water, helped to keep the indoor atmosphere hot and humid. Glass was covered with insulation overnight to keep the warmth in, or used only on the south side together with better insulated walls, to take in and hold heat from the midday sun.

The Crystal Palace

When glass structures were transformed into spaces for human habitation, the new challenge was to keep the interior sufficiently cool. Preventing overheating in glass buildings has proven enormously difficult – even in Britain’s temperate climate. The Crystal Palace in Hyde Park – a temporary pavilion built to house the Great Exhibition of the Works of Industry of All Nations in 1851 – was a case in point.

Painting of Queen Victoria opening the Crystal Palace in London, 1851. Image: Thomas Abel Prior/Wikimedia Commons.

The Crystal Palace was the first large-scale example of a glass structure designed specifically for use by people. It was designed by Joseph Paxton, chief gardener at the Duke of Devonshire’s Chatsworth Estate, drawing on his experience constructing timber-framed glasshouses.

Though recognised as a risky idea at the time, organisers decided to host the exhibition inside a giant glasshouse in the absence of a more practical alternative. Because of its modular construction and prefabricated parts, the Crystal Palace could be put together in under ten months – perfect for the organisers’ tight deadline.

To address concerns about overheating and exposing the exhibits to too much sunlight, Paxton adopted some of the few cooling methods available at the time: shading, natural ventilation and eventually removing some sections of glass altogether. Several hundred large louvres were positioned inside the wall of the building, which had to be adjusted manually by attendants several times a day.

Despite these precautions, overheating became a major issue over the summer of 1851, and was the subject of frequent commentaries in the daily newspapers. An analysis of data recorded inside the Crystal Palace between May and October 1851 shows that the indoor temperature was extremely unstable. The building accentuated – rather than reduced – peak summer temperatures.

A timeline of the temperature in the Crystal Palace, May to October, 1851. Image: Henrik Schoenefeldt/author provided.

These challenges forced the organisers to temporarily remove large sections of glazing. This procedure was repeated several times before parts of the glazing were permanently replaced with canvas curtains, which could be opened and closed depending on how hot the sun was. When the Crystal Palace was re-erected as a popular leisure park on the outskirts of London, these issues persisted – despite changes to the design which were intended to improve ventilation.

Chicago glass

These difficulties did not perturb developers in Chicago from building the first generation of highly glazed office buildings during the 1880s and 1890s. Famous developments by influential architect Ludwig Mies van der Rohe, such as the Crown Hall (1950-56) or the Lakeshore Drive Apartments (1949), were also designed without air conditioning. Instead, these structures relied mainly on natural ventilation and shading to moderate indoor temperatures in summer.

In the Crown Hall, each bay of the glass wall is equipped with iron flaps, which students and staff of the IIT School of Architecture had to manually adjust to create cross-ventilation. Blinds could also be drawn to prevent glare and reduce heat gains. Yet these methods could not achieve modern standards of comfort. This building, and many others with similar features, were eventually retrofitted with air conditioning.

Chicago’s Crown Hall. Image: yusunkwon/Flickr/creative commons.

Yet it’s worth noting that early examples of glass architecture were not intended to provide airtight, climate controlled spaces. Architects had to accept that the indoor temperature would change according to the weather outside, and the people who used the buildings were careful to dress appropriately for the season. In some ways, these environments had more in common with the covered arcades and markets of the Victorian era than the glass skyscrapers of the 21st century.

Becoming climate conscious

The reality is that the obvious shortcomings of glass buildings rarely received the attention they warranted. Some early critics raised objections. Perhaps the most outspoken was Swiss architect Le Corbusier, who in the late 1940s launched an attack on the design of the UN Secretariat, arguing that its large and unprotected glass surfaces were unsuitable for the climate of New York.


But all too often, historians and architects have focused on the aesthetic qualities of glass architecture. The Crystal Palace, in particular, was portrayed as a pristine icon of an emerging architecture of glass and iron. Yet in reality, much of the glass was covered with canvas to block out intense sunlight and heat. Similarly, the smooth glass facades of Chicago’s early glass towers were broken by opened windows and blinds.

There’s an an urgent need to take a fresh look at urban architecture, with a sense of environmental realism. If de Blasio’s plea for a more climate conscious architecture is to materialise, future architects and engineers must be equipped with an intimate knowledge of materials – especially glass – no less developed than that held by 19th century gardeners.

The Conversation

Henrik Schoenefeldt, Senior Lecturer (US: Associate Professor) in Sustainable Architecture, University of Kent.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

What are Europe’s longest train journeys?

The Orient Express was a pretty long train. Image: Getty.

For reasons that aren’t clear even to me, a question popped into my head and refused to leave: what’s longer? Britain’s longest train joruney, or Germany’s?

On the one hand, Germany is quite a bit larger – its area is 70 per cent more than Great Britain’s. On the other hand, Great Britain is long, skinny island and Germany is much rounder – the distance from John O’ Groats to Lands End is over 1,400 km, but you never have walk over 1,000 km to cross Germany in any direction.

And it turns out these factors balance almost each other out. Britain’s longest train, the CrossCountry from Aberdeen in Scotland to Penzance in Cornwall, runs 785 miles or 1,263 km. Germany’s longest train, the IC 2216 from Offenburg in the Black Forest to Greifswald on the Baltic coast, is exactly 1,300 km. Germany wins by a tiny distance.

Except then I was hooked. What about the longest train in France? Spain? Italy?

So I did what anyone would do. I made a map.

The map above was all drawn with the Deutsche Bahn (Germany Railways) travel planning tool, which rather incredibly has nearly every railway in Europe. The data quality is better for some countries than others (the lines in France aren’t quite that straight in real life), and the measurements may be a bit off – it’s not always easy to find the length of a train service, especially when routes can vary over the year – but it gives us a good idea of what the routes look like.

Let’s start with the UK. The Aberdeen to Penzance route isn’t really for people who want to go all the way across the country. Instead, it’s a way to link together several railway lines and connect some medium-to-large cities that otherwise don’t have many direct services. “Cross-country” trains like these have existed for a century, but because they crossed multiple different company’s lines – and later, multiple British Rail regions – they tended to get ignored.

 

That’s why, when it privatised the railways, the government created a specific CrossCountry franchise so there was a company dedicated to these underused routes. If you want to get from Edinburgh to Leeds or Derby to Bristol, you’ll probably want a CrossCountry train.

The usual route is Edinburgh to Plymouth, but once a day they run an extra long one. Just one way though – there’s no Penzance to Aberdeen train. 

The longest train in Germany is weird – at 1,400 km, it’s substantially longer than the country itself. On the map, the reason is obvious – it takes a huge C shaped route. (It also doubles back on itself at one point in order to reach Stuttgart).

This route takes it down the Rhine, the biggest river in west Germany, and through the most densely populated patch of the country around Cologne and Dusseldorf known as the Ruhr. Germany’s second and third longest trains also have quite similar routes – they start and end in remote corners of the country, but all three have the Rhine-Ruhr metropolitan area in the middle.

You’re not meant to take the IC 2216 all the way from north east to south west – there are much more direct options available. Instead, it’s for people who want to travel to these major cities. They could run two separate trains – say, Offenburg-Dusseldorf and Griefswald-Cologne – but making it a single route means passengers benefit from a bit more flexibility and helps DB use its rolling stock more effectively.

France’s longest train exists for a very good reason. Most of France’s high-speed lines radiate out from Paris, and it’s very hard to get around the country without going to the capital. Usually to get from Marseille on the Mediterranean to Nantes near the Atlantic, you’d need to take a TGV to Paris Gare de Lyon station, then get the Métro across the city to Gare Montparnasse.

Once a day though, this TGV avoids this faff by stopping in the suburb of Juvisy and turning around without going into the centre. This lets passengers travel direct between the coasts and reduces the traffic through Paris’s terminals in the rush hour. The exact length of this route isn’t clear, but Wikipedia says it’s about 1,130 km.

Spain’s longest train is very different. This is the Trenhotel sleeper service from Barcelona to Vigo, and it’s pretty fancy. This is a train for tourists and business travellers, with some quite luxurious sleeping cabins. But it is a regularly scheduled train run by the state operator Renfe, not a luxury charter, and it does appear in the timetables.

Being dry, hot and quite mountainous in its middle, most of Spain’s cities are on its coast (Madrid is the one major exception) and as a result the train passes through relatively few urban areas. (Zaragoza, Spain’s 5th largest city, is on the route, but after that the next biggest city is Burgos, its 35th largest,) This is partly why overnight trains work so well on the route – without many stops in the middle, most passengers can just sleep right through the journey, although there are occasional day time trains on that route too if you want to savour the view on that 1,314 km journey.

Finally, there’s Italy. This is another sleeper train, from Milan in the north to Syracuse on the island of Sicily. It goes via Rome and travels along the west coast of... wait, it’s a train to the island of Sicily? How, when there’s no bridge?

Well, this train takes a boat. I don’t really have anything else to add here. It’s just a train that they literally drive onto a ferry, sail across the water, and then drive off again at the other side. That’s pretty cool.

(As I was writing this, someone on Twitter got in touch to tell me the route will get even longer in September when the line to Palermo reopens. That should be exciting.)

So those are the longest trains in each country. But they aren’t the longest in Europe.

For one thing, there are some countries we haven’t looked at yet with very long trains. Sweden has some spectacular routes from its southern tip up into the Arctic north, and although the Donbass War appears to have cut Ukraine’s Uzhorod to Luhansk service short, even Uzhorod to Kharkiv is over 1,400 km. And then there are the international routes.

To encourage the Russian rich to take the train for their holiday, Russian Railways now run a luxury sleeper from Moscow to Nice, passing through France, Monaco, Italy, Austria, Czechia, Poland, Belarus and Russia. This monster line is 3,315 km long and stretches across most of the continent. That’s got to be the longest in Europe, right?

Nope. Incredibly, the longest train in Europe doesn’t actually cross a single border. Unsurprisingly, it’s in Russia, but it’s not the Trans-Siberian – the vast majority of that’s route is in Asia, not Europe. No, if you really want a long European train journey, head to Adler, just south of the Olympic host city Sochi. From there, you can catch a train up to Vorkuta on the edge of the Arctic Circle. The route zigzags a bit over its 89 hour, 4,200 km journey, but it always stays on the European side of the Ural mountains.

Bring a good book.

Stephen Jorgenson-Murray often tweets about this kind of nonsense at @stejormur.


All maps courtesy of Deutsche Bahn.