The greening of construction (Part I): Overview

In recent years humankind reached a significant milestone when we became a predominantly urban species. This trend towards urbanization is part of the transition from agrarian to industrial society that is radically transforming our social metabolism and threatening the earth system. Although Northern Europe established this trend in the 18th century, it is currently most pronounced in the developing world. In China for example, where rural migrants have for decades been flooding urban spaces, construction spending amounted to $1.25 trillion in 2012.

Yet most construction still occurs in rich countries. This is partly because the urbanizing poor tend to migrate to environmentally efficient slums [1]. You see, a cardboard lean-to is cheap and green – although unlikely to be certified as such. But slums are hardly ‘sustainable’ because the social (or human) pillar of the sustainability triangle is likely absent.

Over the next few weeks I will be examining environmental product declarations (EPD) in the construction sector and looking at how they relate to sustainability rating tools for buildings. This is an area of enormous significance. It is estimated that global spending on construction amounted to $8.7 trillion in 2012 or 12% of GDP. While the correlation between GDP and environmental impact is well established, it is worth noting that buildings punch substantially above their weight. They account for more than half of all extracted materials, a third of greenhouse gas emissions and forty or so percent of final energy consumption. Clearly our built environment casts a significant ecological shadow which implies that the construction industry has an important role to play in beating a path towards sustainability.

But as well as being an issue of scale this is also one of great complexity, because 80% of the built environment’s impact occurs in the operational phase (i.e. when in use). Accordingly, the way in which materials are combined into structures has perhaps as much influence on a building’s overall environmental performance as the nature of the construction materials themselves. Therefore, any attempt to ameliorate the impact of the construction sector must take account of whole life cycles.

Importantly, having readily accessible and relatively comparable life cycle assessments of material actually embedded in structures (including infrastructures) and consumed in the construction process is a precondition for assessing, reporting on, and improving the sustainability of structures. Software, such as Umberto, offers databases that expedite the provision of such information which is vital as we slowly drift along the long road to toward sustainability.

Indeed, writing in Sustainable Development a few years ago Helmut Haberl and his collaborators suggested that our “industrial society is at least as different from a future sustainable society as it is from the agrarian regime” [2]. I cite the case of China as an example of a rapidly dissolving agrarian regime, but will let history judge how successfully industrial society dissolves into sustainability.

Anyway, despite their solid environmental and economic performance, I am not about to advocate for more slums, because the social impact of buildings also matters.  A holistic assessment of buildings must encompass economics, human health and welfare and the environmental performance across a range of impact categories. Fortunately, the market is increasingly demanding this information.

The growing call from tenants and owners for greener buildings has spawned a swarm of standards and tools for measuring performance. This in turn has provided an impetus for the harmonization of green building standards internationally. Property investors with global portfolios want international comparability because green buildings are economically efficient. This is an encouraging example where a relatively environmentally sound product is sought because its greenness enhances social and economic bottom lines. There is no ecological altruism required here.

This pull towards sustainability has galvanized the European Commission to push towards a harmonized format for building assessments. Although such assessments are made at a building level, not a product level, it only makes sense that as part of this harmonization a more standardized EPD scheme be implemented for construction materials. To these ends the ECO Platform was launched last September “to support the provision of unbiased credible and scientifically sound information in [the] form of a type III Environmental Product Declaration (EPD) for construction products”.

Next week, in part II of this foray into the construction sector, I will compare the development of EPDs in three different regional markets; my current stomping ground, the Asia Pacific; Europe; and the US. The following week will be devoted to building sustainability rating tools in these different markets and will assess the progress that is being made towards international harmonization.

The picture of Kashgar’s ethnic divide shows a Uighur foreground against a Han backdrop. It was taken by the author during a bicycle ride across Asia in 2012. I note that traditional, resource efficient Uighur structures are being demolished under planning instruments which mandate ‘quake-resistance’.