Low-tech Magazine

The solar envelope: how to heat and cool cities without fossil fuels

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Architects all over the world have demonstrated the usefulness of buildings which are heated and cooled by design rather than by fossil fuel energy. What has received much less attention, however, is the possibility of applying this approach to entire urban neighbourhoods and cities.

Designing a single, often free-standing, passive solar house is quite different from planning a densely populated city where each building is heated and cooled using only natural energy sources. And yet, if we want passive solar design to be more than just a curiosity, this is exactly what we need. Modern research, which combines ancient knowledge with fast computing techniques, shows that passive solar cities are a realistic option, allowing for surprisingly high population densities.

Illustration by Diego Marmolejo for Low-tech Magazine.

Insulation: first the body, then the home

You could fill a library with reports and books describing the importance of energy-efficient heating systems and home insulation. However, not a word has been said or written about the energy savings potential of clothing, even though there has been a lot of progress in this area too. Modern thermal underclothing offers the possibility to turn the thermostat much lower without sacrificing comfort or sex appeal. The potential energy savings are huge; the costs are almost nil.

This article explains through science and statistics how to maintain thermal comfort at any given indoor temperature using only clothes.

The sky is the limit: human powered cranes and lifting devices

From the earliest civilisations right up to the start of the Industrial Revolution, humans used sheer muscle power, organisation skills and ingenious mechanics to lift weights that would be impossible to handle by most power cranes in operation today.

Rings of fire: Hoffmann kilns

About a year ago we presented a medieval building technique that could save large amounts of brick and thus embodied energy in construction: timbrel vaulting. Turns out that there is also a 19th century brick and tile production technique that is surprisingly energy efficient: the Hoffmann kiln, a giant version of the medieval oven stove.

Tiles as a substitute for steel: the art of the timbrel vault

The craftsmanship associated with timbrel vaulting has long vanished, but the achievements are still with us today.

Brick, stone and concrete are materials strong in compression (you can pile them up almost indefinitely), but weak in tension (if the structural breadth increases, the material has to be supported by many columns or it collapses).

Nowadays, this problem is solved by steel structures or the use of steel reinforced concrete - the tensile strength of steel is significantly more than that of bricks, stone or plain concrete. Pre World War II, the weak tensile strength of brick was compensated for by superior craftsmanship.

The "timbrel vault" allowed for structures that today no architect would dare to build without steel reinforcements. The technique was cheap, fast, ecological and durable.

Heat your house with car tyres and earth

Energy hungry America teaches the world how to build ecological houses.

A dirt cheap and 100 percent ecological house that has all the comforts of an ordinary home, without being connected to the electricity grid, waterworks, sewer system or the natural gas network. It does exist, but in most countries, building one is not allowed.

An Earthship is a completely self-sufficient house that has a natural temperature regulation, without the use of a heating system. The building also generates its own electricity, collects and filters its own drinking water and cleans its own effluent water. The house is partly buried into the earth and is constructed mainly with waste materials; car tyres, aluminium cans and glass bottles. This low-tech building approach is ecologically as well as economically advantageous.

This autumn, the British coastal city of Brighton approved the construction of 16 Earthships. It’s the first time that a European city council has given builders the green light to mass construct this radical ecological housing form. In the United States nearly one thousand Earthships have been built, most of them in the desert of New Mexico. (Pictures: Michael Reynolds)

Lego for Big Boys: habitable shipping containers

Habitable shipping containers promise cheap, modular and comfortable housing.

Cars, washing machines, televisions: almost everything we can buy today is assembled on the conveyor belt of some factory. But our houses are still built on the spot by a team of workers. Accompanied by lots of noise for the neighbours, and hampered by the weather. That could change: a growing number of architects see the very thing in habitable shipping containers.