Challenge for society
Globally, buildings are responsible for approximately 30% of all energy use. Some of that energy is going to be provided by electricity that comes from wind turbines which do not have any emissions associated with it. The lion share of it, however, is not coming from renewable sources and, more importantly, in areas where you have heating provision, much of the heating is coming from gas. This means we have a lot of problems with buildings, new and existing. Even new buildings are already built with an infrastructure that they are gonna be emitters for some time into the future.
Can these emissions be reduced to zero?
I believe we can absolutely get to zero emissions in buildings. The first answer is that we need to try to reduce the energy use per person per square metre in a building and this just means making our buildings more energy efficient in the first place.
Things like improving the insulation levels which will therefore reduce, in winter, the heating bills, actually in summer, if you air-condition the building, we even reduce the air-conditioning loads because you are shielding the interior from the external solar gain in hot temperatures.
So, making our buildings more efficient is the first objective. The second one (and this is important) is particularly pertinent for existing buildings and is that whatever energy is being used by the building is switched to electricity. Not gas for example, for heating, because if gas is your vector for providing a source of heat for the building, which will then ignite, you then have the emissions increasing from that building.
So, these are the two main steps: make the building more energy efficient in the first place and then go and make sure that you are using electricity as your vector.
We need to provide the occupants with enhanced air quality, enhanced comfort conditions as society progresses.
We must rigorously implement building standards
New buildings are built to much higher standards than they were 30/40 years ago. If building standards and regulations are applied by the construction industry, including the designers, the contractors that build the buildings, and the people who go and check the buildings, as long as everyone is singing from the same hymn sheet, and singing properly, you will end up with buildings that are built rather well, and in particular, you will end up with buildings that for example, keep the heat in, in the winter.
Think about an office building that is not occupied 24 hours a day, 7 days a week. Most offices are not. People are inside maybe 12 hours a day. Let’s say we actually have a work-life balance and it’s 8 hours a day. So it’s one third. We are left with two-thirds of the day where it is relatively unoccupied and all the heat that is being generated by the IT equipment.
What you want to do is make sure that the building doesn’t cool down at night, which then requires a whole load of energy to pre-heat the building the following morning.
So as long as the building is well insulated and reasonably air-tight, that building can almost run for free when it comes to heating. It is the heat that was generated the previous day that is being used to make sure that the place is still warm at the beginning of the next day. Once people are in there, they can work pretty much for free, especially if you have a heat recovery system.
If we used globally, current building standards from countries like the UK, there is a lot that can be done to vastly reduce energy use and therefore carbon emissions associated with the building’s environment.
But these are big “if’s”!
Certainly in the UK, the construction industry has had some challenges and they were laid bare with the very tragic and dreadful Grenfell Tower incident.
The standards are the one thing, applying those is another. And that is the issue that we have in the construction industry. To really make great strides is about improving the way of working within the industry. This is an important lesson learned in the UK that can be shared more widely because it is likely that these sorts of problems exist elsewhere in the world.
Can the buildings go further into a negative emissions territory?
We have a problem that, just getting to net zero emissions is not going to be sufficient, we need to go harder than that. We need to take greenhouse gases out of the atmosphere. We have got to undo the damage that we have been inflicting on the climate since the industrial revolution.
There are some technologies being developed right now that could possibly be applied to buildings. One of these is looking at the oxidation of methane in the atmosphere. Methane itself is a fairly low concentration greenhouse gas at1.7 or 1.8 parts per million. If you compare that with carbon dioxide at 415 parts per million, at first glance one might think, well, let’s focus on the higher concentration gas.
The problem is that methane has got much higher global warming potential and a shorter-lived presence within the atmosphere. It decays more quickly than carbon dioxide in about 12 years but has got 120 to 140 times the warming effect.
How do we get rid of Methane at such low concentrations?
There are technologies being developed right now, called photocatalytic converters, where the job is to try and convert the methane into Carbon Dioxide. So, well why converting one greenhouse gas into another, well it is because it is far less potent, it will last then a lot longer of course, in the atmosphere, as the CD but that is what is going to get oxidised to naturally, anyway. I just want to accelerate the oxidation so that we can get this stuff out of the atmosphere.
Photocatalytic oxidation of methane is well known, but it is still being developed to figure out what the costs are, and, how on earth you can get enough of the atmospheric air passing over this photocatalytic substrate, which can be something like zinc oxide or titanium dioxide.
The idea is that we can combine what we already doing in society, much of which has got a lot of surface area, not just buildings but the infrastructure such as roads, with this technology.
The amount of the infrastructure that we are building is huge and every surface, therefore, has got potential for air to move it across it naturally as a result of wind and buoyancy floats.
So, the role of the built environment as a potential way of coating materials for getting rid of our Methane is extremely exciting.
It is still at a cost stage because we have got to get the costs of the material down sufficiently so that we can make it worthwhile, for relatively small amounts of air passing at any given square metre, but we have so many sq. metres of the built environment, I think it is worth exploring.
Making human habitats a more integrated part of the biosphere
We do need to think differently about our built environment going forward, and it is not just about climate change. Climate Change is clearly the biggest existential threat we are facing right now but the way to go and tackle climate is to integrate it with other challenges that we have such as, for example, our well-being.
How can I get people to spend more money on the buildings environment today when the real beneficiaries of that money are going to be the next generation?
The way to think about this is to look at the benefits of changing our built environment. For example, the use of more plants within our built environment provides a cooling effect with shade in hotter periods.
The way we design our cities requires a lot more green space and I don’t just mean having parks. I mean green space even within our streets. We urgently need different ways of thinking about how we might make our cities more in harmony with a more natural environment.
These are the sort of developments I would like to see being pursued where we can reduce our energy emissions, our energy use, carbon emissions and thus climate impacts while providing benefits right now to our society.