Decarbonisation of standing buildings – one of the greatest challenges of green transformation

Green transformation for the real-estate market means huge change, making it visibly greener, by changing most buildings, especially standing ones, into more energy efficient ones. More energy efficiency – less CO₂ emissions. The EU’s Green Deal has set an ambitious target with a goal of carbon neutrality within all EU countries and their economies in 2050. Implementing this vision is easier for new construction, where one can build a nearly zero-energy building, achieving a set level of energy demand, getting the required energy performance certificate (EPC) and carry out life cycle assessments. However, the situation is complicated when thinking about improving energy efficiency in a 20-years old building with inefficient HVAC system, without proper insulation, with old gas boilers, single-glazing windows and with energy intensity greatly exceeding CRREM pathways (Carbon Risk Real Estate Monitor is the leading global standard and initiative for operational decarbonisation of real estate assets.)

The European Environment Agency estimates that around 80-95% of existing buildings will still be standing in 2050, and that many of them are classified as inefficient ones.

Conducting successful green transformation in standing buildings

There are many tools and instruments that could help tackle the essence of the problem: reducing emissions and energy consumption. One of them is the above-mentioned CRREM tool, a perfect base for carbon emissions and energy intensity estimations and can help visualise the scale of decarbonising a building. There are general guidance sets provided by the World Green Buildings Council, along with local ones from the Polish Green Building Council that come in handy too.

Recommendations related to the decarbonisation of standing buildings can be divided into four steps, and should be followed in this order, and all four considered as an entire process:

1. Improving energy efficiency – the highest priority and the first step of decarbonisation, reducing energy consumption
2. Installing on-site renewable energy, to further reduce energy demand after the first step
3. Off-site renewable energy – buying energy covered by certificates of origin to neutralise remaining operational emissions
4. Offsetting – compensating for emissions that cannot be reduced or neutralised (such as embodied ones) by buying carbon credits, but only from accredited sources

The Polish Green Building Council identifies some circularity considerations that should be taken into account during the retrofitting or refurbishment process and new construction, which for the purpose of this article are not listed here but are hugely recommended, especially in the decarbonisation of buildings located in Poland.

Why following the above pattern, step by step, is so important

It has to be stressed that absolute carbon neutrality is almost impossible for most standing buildings. Each of them will be using energy after retrofits and most likely this energy demand will not be met by on-site renewables only, as areas of potential use for the purpose of on-site renewable installation are simply too small to meet the energy needs of a building, even perfectly retrofitted and with energy efficiency improved as much as possible.

Improving energy efficiency in a building is a huge process requiring a specific knowledge in fields of engineering and architecture, carbon calculations, circularity of materials – as well as lots of cash. Patience in implementation will be a key too, as this is not a process that can be accomplished overnight. It is a process that has to be done with a holistic approach to a building, well-planned, often tricky, and carried out over a longer time horizon.

Following the above sequence of steps is important to use our resources optimally and in a sustainable way. Of course, each building has to be approached individually when creating a decarbonisation plan, and there might be some differences in the share of the above four steps in the overall decarbonisation. But only by following the sequence will there be no wasted resources.  

There are existing guidelines and recommendations (such as the mentioned above ones) available that can be adopted in every standing building. Additionally, there are many consultancy companies as well as engineering ones that can help create a decarbonisation pathway for a building based on solid experience and widely-used and established practices. Aside from that, one can still be tempted to base a decarbonisation plan on short cuts to avoid some inevitable cost and effort.

In practice

One example of short cut is buying off-site green energy with certificates of origin (step 3), without implementing energy efficiency improvements (step 1) or installing on-site renewables, (step 2), but with the goal of polishing one’s carbon reduction commitments. While it could be done unintentionally by someone not familiar with good market practise, an act of good will and an attempt to reduce environmental impact, this should be stigmatised when used intentionally just to pursue carbon neutrality commitments.

Sustainable development aims at using resources optimally. Let’s take an example by imagining a building that consumes 1 x kWh/year, but after energy efficiency improvements and installation of on-site renewables, it could use 0.5 x kWh/year or even 0.3 x kWh/year. When such a building buys offsite green energy without energy efficiency improvements or on-site renewables (if possible) we can see that at least half of this energy is wasted! And even arguing that renewables like wind or solar energy are infinite, and therefore cannot be wasted, we have to remember about the infrastructure and space needed for this infrastructure. For example, in Poland in the total energy mix, there is only a 21% share of renewable energy, though this is increasing year by year. So it means that such a building would waste resources that are still in development. Buying green energy should be a part of the whole decarbonisation process, as one of the steps and the best in the pattern presented above. It should not be a base for decarbonisation.

There are a few other shortcuts like offsetting all emissions without even bothering to try to go through all the steps of the decarbonisation scheme. But by consistently following a well-prepared plan, with timelines over a year’s horizon, we can do much to deal with green transformation. It has to be remembered that each building should be considered individually as well as in a wider perspective. And, most importantly, by applying commonly used and respected market practices, or with an external help of specialists, you ensure the highest credibility of the investment. Without straying off the road.