Daily Archives: December 13th, 2019

BLOG: Environmental Impact of Construction

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Construction uses vast quantities of cement, steel, copper, plastics, and the actual process of construction itself produces significant CO2.

From 2020 – 2030 embodied carbon in buildings contributes more than normal operating emissions

Rather than build new one method to reduce impact is for an increasing adaptation of existing built infrastructure; though this is not easy as design requirements are often very specific: think of Victorian Terraces, or post-war tower blocks, or Olympic Swimming Pools, or Coal Fired Power Stations for example, Plus, adaptation can be complicated, costly and impactful. It’s not a panacea.

Slipform technique of casting concrete is quick and efficient, but emissions as a result are high. Also concrete buildings are harder to adapt and demolish.

Another green idea is to drastically reduce the use of steel and concrete and instead go back to timber (or other more sustainable materials), but there are downsides, one being increased fire risk. And timber has to be responsibly sourced. Modern day timber is poor quality kiln dried unsuited for UK and other wet climates, so the tendency is to source robust timbers like Western Red Cedar globally which can be harmful and outweigh the benefits.

The Construction industry itself talks about reducing impacts through greater efficiency, systemisation, or just-in-time delivery of materials. But we must be sceptical this is enough! Increased efficiency brings about more construction not greener buildings. It’s becoming increasingly easy to build large and large is where the biggest impacts are. For the future . . maybe there will be a contribution to green construction through the use of 3D printing and robotics? But can technology get us out of the technology fix we’re currently in ?

We should be building out of low-carbon materials at higher densities. for example here is a four-storey multi-family building, which could be built out of materials that store carbon rather than emit it – straw, wood, linoleum, cedar.

Hempcrete is a green building material attracting a lot of interest.

Construction impacts on climate are a big problem. Global growth craves bigger and faster construction. We see this everywhere. To mitigate there must be a greater emphasis in construction-related education / training about green aspects (like the Endeavour Sustainable Building School featured in the tree hugger LINK), not simply reducing operating impacts, but the upfront emissions, and also decommissioning impacts. And construction clients need to be better educated. Clients tend to be the ultimate short termers . . fixed on today’s needs not tomorrow’s.

Depending on specified materials the same building can have widely different emissions.

And fundamentally it all comes down to the way we live and use global resources. What we’re prepared to give up. It’s not pain free.

The Eco Sutton website features greener case examples. But these are more about reduced operating impacts for sure. The Building Research Establishment Environmental Assessment method (or BREEAM) and other environmental assessment tools do include credits for upfront impacts but overall are skewed more towards in-use impacts.

In fact, assessment tools are likely to be compromised as they sit within the existing industry which inevitably is heavily pragmatic and profit based.

LINK about ways buildings can be carbon sinks instead of carbon sources:

https://www.treehugger.com/green-architecture/landmark-study-shows-how-change-building-sector-major-carbon-emitter-major-carbon-sink.html

CREDIT: featured diagrams are taken from the Treehugger Article with thanks.

The term Carbon Use Intensity (CUI): represents a mix of Upfront Carbon Emissions plus (energy use intensity x energy source emissions) = CUI