THE RACE is on to build the world's tallest fully wooden skyscraper. But such edifices are still uncommon.

In 2015 world leaders meeting in Paris agreed to move towards zero net greenhouse gas emissions in the second half of the century. That is a tall order, and the building industry makes even taller.

Cement making alone produces 6% of the world's gas emissions. Steel, half of which goes into buildings, accounts for another 8 percent. If you factor in all the energy that goes into lighting, heating and cooling homes and offices, the world's buildings start to look like a giant environmental problem.

Governments of the rich world are now trying to promote greener behaviour by obliging developers to build new projects to ''zero carbon'' standards.

From January 1st 2019, all new public-sector buildings in the European Union must be built to  ''nearly-zero energy'' standards. All other types of buildings will follow in January 20121. Governments in .eight further countries are being lobbied to introduce a similar policy. 

These standards are less green than they seem. Wind turbines and solar panels on top of buildings look good but are much less productive than wind and solar farms.

And the standards only count the emissions from a running a building, not those belched out when it was made. Those are thought to count between for between 30% and 60 percent of the total over a structure's lifetime.

Buildings can become greener. They can use more recycled steel and can be prefabricated in off-site factories, greatly reducing lorry journeys. No other building material has environmental credentials as exciting and overlooked as wood.

The energy required to produce a laminated wooden beam is one-sixth of that required for a steel one of comparable strength.

As trees take carbon out of the atmosphere When growing , WOODEN BUILDINGS  contribute to negative emissions by storing the stuff.

When a mature tree is cut down, a new one can be planted to replace it, capturing more carbon. After buildings are demolished, old beams and panels are easy to cycle into new structures. And for retrofitting older buildings to be more energy efficient, wood is a good insulator.

A softwood frame provides nearly  400 times  as much insulation as as a plain steel one of the same thickness and over a thousand times as much as an aluminum equivalent.

A race is on to to build the world's tallest fully wooden skyscraper.  But such edifices are still uncommon. Industry fragmentation, vicious competition for contracts and low profit margins mean that most building firms have little money to invest in  greener construction methods beyond what regulation dictates.

Governments can help nudge the industry to use more wood, particularly in the public sector   -the construction industry's biggest client.

That would help  wood-building specialists achieve greater scale and lower costs.

Zero-carbon building regulations should be altered to take account of the emissions that are embodied in materials. This would favor wood as well as innovative ways of producing other materials.

Construction codes could be tweaked to make building with wood easier. Here the direction of travel is wrong.

Britain for instance, is banning the use of  timber on the outside of tall buildings after  72 people died in a tower fire in London in 20017. That is nonsense.

Greenfell Tower was covered in aluminum and plastic, not wood. Modern cross-laminated timber panels perform better in first-tests than steel ones do.

Carpentry alone will not bring the environmental cost of world's building into line. But using wood can do much more than is appreciated.

The World Students Society thanks the authors at, 'The Economist'.


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