In Yemen, there's a city full of 500 year old skyscrapers made of mud

Shibam, Yemen's "mudbrick Manhattan". Image: Jialiang Gao/peace-on-earth.org/Wikimedia Commons.

Deep in Yemen’s most remote valley lies the city of Shibam. Surrounded by palm groves, and flanked by the steep cliffs leading up to the Yemeni highland on both sides, the city of 2,000 inhabitants hardly seems impressive. Just a handful of high-rise residential buildings, not so different from the Soviet-style blocks found across the Arab world.

Yet  these buildings don’t date from the 20th century, or even the late 19th century. They were built almost five centuries ago, and have remained largely unchanged since.


On a dustless day, the white finish of its walls can be seen from miles away. The city, one of the few to be designated a UNESCO World Heritage site in its entirety, appears to rise from the plains. Its 500 houses reach an astounding 100 feet in height, almost as high as Chicago’s  first skyscrapers. Perhaps most remarkable of all is the fact that the city was built using nothing but mud.

From a historical point of view, this is an incredible piece of engineering. But does the city also hold the key to a more sustainable architecture? Salma Damluji, the world’s foremost expert on Arabia’s traditional architecture, thinks the city’s use of mudbrick – bricks that have been dried in the sun rather than fired – is a key technique developed to cope with challenges posed by the harsh climate.

A close up of the "skyscrapers". Image: Aiman Titi/Wikimedia Commons.

Mudbrick has a higher heat capacity and lower conductivity than concrete, which means it slows the rate at which the temperature within the building changes. It’s also cheap to produce - labour costs are the only real costs involved - and it’s eco-friendly. Not only does the production of sun-dried bricks involve no polluting emissions, the bricks are also reusable.

And, unlike fired bricks, the physical structure of dried bricks does not change during the drying process. Without its white protective layer, a wet brick simply becomes mud.

In Shibam, climatic considerations manifest themselves in more than just the building material. Wooden windows provide privacy, refract glare and promote air circulation with their low placement, and small ventilation holes near the ceiling. Narrow streets and open plazas further enhance this air circulation on a city level. Thus, the architecture of Shibam reveals a complete approach to urban planning, fine-tuned to the city’s climate and social structure.


Although Shibam’s skyline probably forms its pinnacle, mudbrick architecture is widespread in the Middle East. One of its greatest champions was the Egyptian architect and intellectual Hassan Fathy (1900 – 1989), whose architectural philosophy took great inspiration from the socialist politics of Egypt’s anti-colonial hero: Gamal Abdel Nasser.

James Steele, in his biography of the architect, writes that, “On the one hand, Fathy respected and admired European traditions, while on the other hand he resented them as part of a colonial legacy that had threatened Egypt’s identity.”

Spurred on by discomfort with European models of architecture and urban planning, Fathy researched a wide range of architectural traditions native to Egypt. Though he was greatly impressed by both Pharaonic and Islamic monumental architecture, he was more directly influenced by the vernacular architecture of rural Nubia, an area covering the south of Egypt and the north of Sudan.

It was in Nubia where he first encountered mudbrick. “Once convinced of the long history, durability and cultural applicability of mudbrick, as well as its low cost and environmental advantages,” Steele writes, “Fathy saw no reason why it should not be used on a wider scale.”

Towards the end of his life, he was widely recognised for his development of an architectural philosophy that integrated modern technology with the demands of local culture and nature, winning the Aga Khan Award for Architecture in 1980.

And yet it appears that his work failed to make a lasting impact on architecture in the Middle East. No large scale projects involving traditional building methods exist, and even Shibam is under threat.

While decades of political instability and the current war between Houthi rebels and the Saudi-backed government forces have largely passed by the remote valley, Shibam’s architecture has been in decline since the nationalisation of many of its buildings. Although the buildings are rented out to their original owners, a lack of ownership has made their inhabitants reluctant to invest in the considerable maintenance costs. Without regular maintenance, crucial experience with traditional building methods risks being lost forever.

In close up. Image: Jialiang Gao/peace-on-earth.org/Wikimedia Commons.

And local tradition is crucial. When Oxfordshire organic farmers Lutfi and Ruby Radwan, inspired by the mud brick architecture of Saudi Arabia and Senegal, built Willowbrook Farm, they decided to use similarly eco-friendly methods. However, Britain’s climate is, unsurprisingly, not quite dry enough for sundried bricks.

“Instead, we built using the traditional British method of mixing the cob and building up directly in a continuous lump,” Lutfi says. “We admire Hassan Fathy’s work, but it didn’t influence us greatly. More importantly I had visited a number of mud buildings in Britain to see how local issues were dealt with.”

“Mudbrick architecture is more sustainable and cheaper if one factors in the environmental costs,” he continues. “Materials and labour can usually be sourced locally, so it benefits a local economy rather than relying on inputs from outside, which also affects energy costs involved in transportation.

"Plus, its environmental impact is minimal. These traditional methods are certainly a viable alternative to less environmentally sustainable modern methods.”

Sustainable, local architecture. With a shortage of 3.5m affordable homes reported in the Middle East and North Africa, perhaps an affordable, durable and eco-friendly solution lies in the traditions of a forgotten Yemeni valley.

 
 
 
 

Transport for London’s fare zones secretly go up to 15

Some of these stations are in zones 10 to 12. Ooooh. Image: TfL.

The British capital, as every true-blooded Londoner knows, is divided into six concentric zones, from zone 1 in the centre to zone 6 in the green belt-hugging outer suburbs.

These are officially fare zones, which Transport for London (TfL) uses to determine the cost of your tube or rail journey. Unofficially, though, they’ve sort of become more than that, and like postcodes double as a sort of status symbol, a marker of how London-y a district actually is.

If you’re the sort of Londoner who’s also interested in transport nerdery, or who has spent any time studying the tube map, you’ll probably know that there are three more zones on the fringes of the capital. These, numbered 7 to 9, are used to set and collect fares at non-London stations where the Oyster card still works. But they differ from the first six, in that they aren’t concentric rings, but random patches, reflecting not distance from London but pre-existing and faintly arbitrary fares. Thus it is that at some points (on the Overground to Cheshunt, say) trains leaving zone 6 will visit zone 7. But at others they jump to 8 (on the train to Dartford) or 9 (on TfL rail to Brentwood), or skip them altogether.

Anyway: it turns out that, although they’re keeping it fairly quiet, the zones don’t stop at 9 either. They go all the way up to 15.

So I learned this week from the hero who runs the South East Rail Group Twitter feed, when they (well, let’s be honest: he) tweeted me this:

The choice of numbers is quite odd in its way. Purfleet, a small Thames-side village in Essex, is not only barely a mile from the London border, it’s actually inside the M25. Yet it’s all the way out in the notional zone 10. What gives?

TfL’s Ticketing + Revenue Update is a surprisingly jazzy internal newsletter about, well, you can probably guess. The September/October 2018 edition, published on WhatDoTheyKnow.com following a freedom of information request, contains a helpful explanation of what’s going on. The expansion of the Oyster card system

“has seen [Pay As You Go fare] acceptance extended to Grays, Hertford East, Shenfield, Dartford and Swanley. These expansions have been identified by additional zones mainly for PAYG caping and charging purposes.

“Although these additional zones appear on our staff PAYG map, they are no generally advertised to customers, as there is the risk of potentially confusing users or leading them to think that these ones function in exactly the same way as Zones 1-6.”


Fair enough: maps should make life less, not more, confusing, so labelling Shenfield et al. as “special fares apply” rather than zone whatever makes some sense. But why don’t these outer zone fares work the same way as the proper London ones?

“One of the reasons that the fare structure becomes much more complicated when you travel to stations beyond the Zone 6 boundary is that the various Train Operating Companies (TOCs) are responsible for setting the fares to and from their stations outside London. This means that they do not have to follow the standard TfL zonal fares and can mean that stations that are notionally indicated as being in the same fare zone for capping purposes may actually have very different charges for journeys to/from London."

In other words, these fares have been designed to fit in with pre-existing TOC charges. Greater Anglia would get a bit miffed if TfL unilaterally decided that Shenfield was zone 8, thus costing the TOC a whole pile of revenue. So it gets a higher, largely notional fare zone to reflect fares. It’s a mess. No wonder TfL doesn't tell us about them.

These “ghost zones”, as the South East Rail Group terms them, will actually be extending yet further. Zone 15 is reserved for some of the western-most Elizabeth line stations out to Reading, when that finally joins the system. Although whether the residents of zone 12 will one day follow in the venerable London tradition of looking down on the residents of zones 13-15 remains to be seen.

Jonn Elledge was the founding editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites.