Solving the CO2 problem: Buildings in a post-carbon world

The word sustainability has changed a lot throughout my 15-year career and although sustainability has become debased almost to the value of the word “nice”, there has always been one guiding star: reducing CO₂ emissions.

The evidence seems to be clear that anthropogenic CO₂ emissions are increasing the amount of heat retained and could cause catastrophic damage to the environment and humanity. That evidence has triggered a policy and investment responses and you can see the results all around us. Here in the UK, this has led to the 2050 goal to reduce CO₂ emissions by 80% and in the buildings sector, there have been changes to Building Regulations and local policies on renewables, as well as specific CO₂ emission targets like “zero carbon” for all new developments in London.

What if clean energy is going to be less a precious commodity and more like processing power, ever cheaper and more available? That may seem an unlikely scenario but I think it is a fast approaching reality

Working in this sector, I have come to believe that fundamentally we are now able to solve the CO₂ problem. There is a vast amount to do but there need be no qualitative breakthroughs in technology or engineering because we now have the tools, energy generation, storage, and the ability to electrify most fossil fuel use. In addition, the technologies that enable the very low carbon future have now reached critical velocity; solar, energy storage and wind are now driven by their own economics and company policies not subsidies or (so much) by new government policies. (Apparently CO₂ emissions are down to levels last seen in the 1890s.)

Thinking further, what if we are about to enter a period of an abundance of energy at ever reducing prices? What if clean energy is going to be less a precious commodity and more like processing power, ever cheaper and more available? That may seem an unlikely scenario but I think it is a fast approaching reality. Prices of the wind, solar and energy storage have been and are dropping, new technologies are coming, we have an open market in technologies and our energy system is becoming more competitive all the time.

If I am right and this scenario will be with us in within 20 years or so, then this has profound implications for how we should be approaching the built environment. It wouldn’t mean that energy efficiency isn’t important or that we shouldn’t regulate energy use now, but that perhaps the balance needs to lean more towards the quality of the human experience.

We have already seen how the drive for diesel engines in vehicles, and gas combined heat and power in our buildings, supposedly to reduce CO₂ emissions, has left us with a legacy of air pollution and I think there are other, more subtle parallels where current CO₂ / energy regulation may have negative consequences. A couple of small examples:

• Building Regulations mean that on new flats we are often working to reduce the window size and/or energy they let through to avoid the need for cooling. What if we should be maximising the size of windows to let in lots of light for the benefit of the occupant’s circadian rhythm, health and happiness? (We often have tension between daylighting guidelines and CO2 targets.) At the moment regulations won’t allow it but will that look sensible in 20 years? Will we be rueing our temporary challenges of today leaving us with buildings that are energy efficient but dark and not great places to be?
• In commercial buildings, research suggests that if we reduce CO₂ levels in work places through higher ventilation rates (beyond the standard 8-10l/s/p that people can concentrate better) and if we use better filtration on air intakes to reduce pollution levels, then people will be healthier. This is all well and good but it substantially increases energy demands. If you are a company with a target to reduce CO₂ emissions, perhaps you will prefer to focus on that rather than the performance of the building.

I emphasise that I am not suggesting energy efficiency isn’t important or that we shouldn’t construct buildings that are low carbon but that we must not let the solutions of today create the problems of tomorrow.