We need to imminently and dramatically reduce our use of and reliance on concrete and steel, two highly energy-intensive building materials which account for around 15% of total global carbon dioxide emissions. We can achieve this through two simple measures.  

The first is to build less. We need to curtail the culture of rampant over-production in the building industry, evidenced by the three major schemes announced for London in the past week, and encourage the refurbishment of functional existing buildings.