Buildings produce a huge amount of carbon. Using more wood would be greener

The second little pig was unlucky. He built his house from sticks. It was blown away by a huffing, puffing wolf, which promptly gobbled him up. His brother, by contrast, built a wolf- proof house from bricks. The fairy tale could have been written by a flack for the construction industry, which strongly favours brick, concrete and steel. However, in the real world it would help reduce pollution and slow global warming if more builders copied the wood-loving second pig.


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

even taller. Cement-making alone produces 6% of the world’s carbon emissions. Steel, half of which goes into buildings, accounts for another 8%. If you factor in all of 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 in the rich world are now trying to promote greener behaviour by obliging developers to build new projects to “zero carbon” standards (see International section). 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 2021. Governments in eight further countries are being lobbied to introduce a similar policy.


promptly 迅速的;立即 gobble 狼吞虎咽的吃 proof 证据;证明 stick 刺;树木 brick 砖;砖块 fairy 故事中的小仙子 tale 故事中的历险记 flack 广告;宣传 oblige 强迫;迫使 lobby 门厅;大厅


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 running a building, not those belched out when it was made. Those are thought to account for between 30% and 60% 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. But no other building material has environ-mental 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 recycle into new structures. And for retrofitting older buildings to be more energy efficient, wood is a good insulator. A softwood window frame provides nearly 400 times as much insulation as a plain steel one of the same thickness and over a thousand times as much as an aluminium equivalent.


emission 发出,射出;排放物

belch out 喷出

prefabricate 预制; 预制性

credential 提供证明

laminate 薄片制成的材料

beam 光线;波束


*noun* [U]






demolish 拆除;拆毁

panel 嵌板;嵌条

retrofit 翻新;改型

insulator 隔热/隔音材料

thickness 厚;厚度

aluminium 铝

Last modification:April 16th, 2020 at 03:13 pm