Urban areas account for 78 per cent of the world’s energy use. Now, a report on greenhouse gas emissions over the whole lifecycle of buildings has found that high-density, low-rise cities such as Paris may be best for reducing emissions. The report, published in the journal Urban Sustainability, concluded that high-rise, high-density buildings increase greenhouse gas emissions by 154% compared to low-rise, high-density buildings.
"Our results show that density is indeed needed for a growing urban population, but height isn’t,” said the lead author and Edinburgh Napier University professor Francesco Pomponi in an article for the World Economic Forum. “So it seems the world needs more Parises and fewer Manhattans – as much as I love New York – in the next decades.”
Traditionally, urban environment design has focused on operational energy use without properly considering the “energy and emissions that are used or generated during the extraction and production of raw materials, the manufacture of the building components, the construction and deconstruction of the building, and the transportation between each phase”, explains the article.
Los Angeles recently became the first local government to regulate the global warming potential of building materials by adopting guidelines to reduce greenhouse gas emissions. Similarly in Norway, construction equipment in Oslo will be required to move from fossil fuel to electric-powered thanks to a zero-emissions target for municipal building sites by 2025. However, for the C40 group, it is not enough for buildings to have net-zero operational energy use: it has launched a declaration aimed at reducing emissions by at least 50 per cent for new buildings, major renovations and infrastructure projects by 2030.
