The Carbon Column – Rome wasn’t built in a day

In this post I discuss embodied carbon in the built environment. Were Roman building methods more sustainable than today?

Big Zero Report 2022

Our global population is expected to grow to nearly 10 billion by 2050. More people equals more buildings.

The building and construction industry contributes significantly to global carbon emissions. More than 35%. This is set to double if something is not done.

It is believed manufacturing cement alone accounts for 7% of the global emissions.

When considering the carbon emissions associated with the built environment, two types of carbon can be considered. Embodied carbon and operational carbon.

Embodied carbon is the emissions during extraction, transportation and manufacturing of raw materials. It is also the carbon emitted during the demolition and end of life phase. This type of carbon is much more difficult to calculate.

Operational carbon is the emissions during the operations of the building. The heating, cooling, lighting, structural maintenance, and anything else you can think of during use.

Creating a sustainable built environment is a complex dilemma. But are we missing a trick taught to us by history?

Roman holiday

My friends are currently travelling round Italy. They’re sending pictures of the roman architecture. It is remarkable place with some of the most beautiful buildings. They were designed to stand the test of time.

Researchers believe the concrete used by romans was much more environmentally friendly, resulting in lower embodied carbon.

It was more environmentally friendly as the materials used were different to the clay limestone mix of today. This old compound required lower temperatures. Lower temperatures means less energy.

Some of these buildings are still standing today, over 2000 years on. Can we say the buildings built today will stand for the same amount of time? I’m not so sure.

I am not saying let’s go back to building this way. It wouldn’t work. It isn’t viable. But what is more sustainable than a building that is built once and lasts thousands of years? And what is more important, speed of building or the sustainability?

Can modern science fix it?

Today we are cutting operational emissions with increased renewable energy consumption, better energy efficiency, energy management and more accessible low carbon technology.

Operational carbon accounts for approximately three quarters of the emissions from the built environment, so you can see why there is a push to reduce this. It is also much easier to do.

Policy is expected to increase energy performance requirements across buildings. The policy will come into play this month and it states ‘under the new regulations, carbon emissions from new build homes must be around 30% lower than current standards and emissions from other new buildings, including offices and shops, must be reduced by 27%.’

Existing technology such as heat pumps and solar panels will help builders and developers achieve this. It puts pressure on them to put sustainability at the heart of their design and construction.

And it will help people reduce energy spending.

All this progression is focused on reducing operational carbon. But what about embodied carbon?

This is more challenging. Solutions required to achieve net zero embodied carbon are not available yet. We need scaled hydrogen-based production for steel and iron making, as well as innovation for production processes.

The Romans aren’t here to tell us how they made things last, yet history should inspire us to make our buildings of the future as long lasting and sustainable.

I am keen to learn more and discuss this topic with industry experts. Please get in touch if you have thoughts around this, or any other net zero topic.

If you enjoyed this story you can sign up to our weekly email for Energy Live News – and if you’re interested in hearing more about the journey to net zero by 2050, you can also sign up to the future Net Zero newsletter. 

Latest Podcast