With the fast pace that the world is developing, the amount of physical infrastructures is bound to increase. While we cannot completely halt the construction of buildings — that would have serious implications from an economic standpoint— the very least that we can do is build them so that they are sustainable.

In line with this, Arup recently released a five minute guide on achieving zero net energy and carbon (ZNE+C) in buildings. Let’s dive in.

What is zero net energy?

Before we even begin to discuss ZNE+C buildings, we first have to know what zero net energy (ZNE) and zero net carbon (ZNC) buildings are.

In a nutshell, ZNE buildings produce more or as much energy as they consume each year.

Meanwhile, a ZNC building would consume only carbon-free renewable energy. On the other hand, a ZNE building is more concerned with the energy operations of a building rather than the emissions.

A ZNE+C building is the combination of the attributes of ZNE and ZNC buildings. It ensures that while a building is operating in zero net energy, the systems that enable it to do so are also carbon-free.

Balancing the scales

According to Arup, energy costs are expected to rise in the succeeding years. It is desirable to create a building which could practically supply its own energy. From a business standpoint, this benefit of a ZNE+C building is undeniably attractive.

Apart from the financial appeal, ZNE+C buildings will also be the solution that we need to address the imminent problem of fossil fuels running out in the future. According to Arup:

  • Oil supplies will last up to 2067
  • Natural gas reserves will remain until 2070
  • Coal deposits are exploitable until 2151

Right now, it might seem that these years are far, far ahead. However, if we take into account the time it would take before our infrastructures become fully sustainable, we can say that this isn’t so much time at all.

Of course, there is also the problem with air pollution which threatens millions of lives each year, not only because of our increased susceptibility to respiratory diseases but also due to these emissions contributing to the pollution warming up our planet.

Taking all these factors into account, we can see that the case is substantially strong in favor of ZNE+C buildings.

The ZNE+C Approach

Arup laid down the ZNE+C approach. This approach pinpoints six guiding principles in the construction of sustainable buildings:

Source: Arup
  1. Load Reduction, pertaining to the use of passive design strategies like improving insulation in order to lower the building’s overall energy demand.
  2. Passive strategies, which is the harnessing of environmental conditions in order to meet building loads. Using the natural ventilation surrounding a building is one way to do this.
  3. Efficient systems, referring to systems that have low energy loss during operations.
  4. Energy Recovery, which is the process of capturing the lost energy as additional energy supply. The use of wastewater heat recovery systems is one good example of an energy recovery facility.
  5. Renewables, which is simply the use of renewables to meet demands.
  6. Offsets, which is the offsetting of the energy budget if deemed necessary. An example of an offset would be energy efficiency project investments.

According to Arup, two-thirds of the buildings today are expected to be still around before the 2o50 emission target deadline. Given this, we can see the importance of making sure that these buildings will no longer add to a large amount of emissions present in our planet today. The ZNE+C approach will not only help keep building emissions at bay, it can also improve the health and the experience of the people in these buildings.