Wake-up call

The carbon clock is ticking…faster than most people think. On the basis of the special report provided by the Intergovernmental Panel on Climate Change (IPCC), the Mercator Research Institute on Global Commons and Climate Change (MCC) has found that our CO2 budget for staying below the crucial 1.5°C threshold will be exhausted in around seven years. This means that our set climate goal should not be 2050, as defined in the Paris Agreement, but 2027. Does this make you feel uneasy? It should!

In response to the Paris Agreement, the EU presented the Green Deal on December 11, 2019, with the goal of becoming the first climate-neutral continent by 2050. Among other things, this roadmap envisages promoting decarbonisation of the energy sector and increasing the energy efficiency of buildings.

Why is decarbonisation important and how does it work? 

In its EU taxonomy report, the Technical Expert Group (TEG) on Sustainable Finance has shown that buildings account for around 40% of energy consumption and around 36% of CO₂emissions in the EU.

At the same time, CO₂ emissions from building material production and processing in building construction are increasing. This is a development in the wrong direction!

This is specifically outlined in the EU taxonomy’s technical appendix, which states that, taking into account the goal of operating climate-neutral buildings in Europe by 2050, new buildings have to be planned and built climate-neutrally between 2021 and 2050. The earlier this is implemented, the sooner the 2050 target can realistically be met. On the one hand, this means that efficiency-enhancing reconstructions must be carried out for a large part of the building stock and on the other, a paradigm shift in planning needs to be accelerated. The process should begin with the investors, who should focus on lower-risk project developments to get the ball rolling.

The EU taxonomy was developed to better manage this process; it presents four basic principles relevant for CO₂ reduction:

1.   Construction of new buildings: to lower primary energy demand by 20% of that specified in national building regulations

2.   Reconstruction and renovation of existing buildings: In accordance with the Energy Performance of Buildings Directive (EPBD) or 30% less primary energy demand than in the baseline state

3.   Individual measures and services

4.   Purchase and ownership: Buildings constructed after 2021 must meet the standard stated under “1. Construction of new buildings”.

Buildings constructed before 2021 must be in the top 15% of the national building stock in terms of their primary energy demand.

Today, only 1% of buildings meet the requirements of a net zero carbon building”.

For clarification, the WRI provides an overview of zero building concepts and what each of them encompasses:

• Net Zero Carbon District – A group of energy efficient buildings within an urban district, supplied with renewable energy through nearby off-site sources.
• Net Zero Carbon Building Portfolio – A group of energy efficient buildings that share similar characteristics and fall under the same ownership or management. All buildings are supplied with renewable energy, which generates electricity and heat within the portfolio rather than at individual building level.
• Nearly Zero Energy Building – An energy efficient building that supplies most of its annual energy consumption through on-site or nearby renewable energy sources.
• Net Zero Energy Building – An energy efficient building that supplies all of its annual energy use through on-site or nearby renewable energy sources on a net basis. This means that the building supplies at least the same amount of renewable energy to the grid than it uses from the grid.
• Net Zero Carbon Building – An energy efficient building that produces or procures enough on-site carbon-free renewable energy to meet building operation’s annual energy use.
• Net Zero Carbon Building, including embodied carbon – An energy efficient building that produces or procures enough on-site carbon-free renewable energy to meet building operation’s annual energy use, and also over its life cycle (meaning it compensates for the carbon embodied in the building’s construction and materials).
  

Best of five – Finding the best scheme to achieve your net zero goal

Since building construction and operation account for around 40% of global CO₂ emissions, various initiatives have been launched in recent years to advance the climate goals set at the Paris Climate Change Conference in 2015. We would like to give an overview and present our opinion on the most important schemes. After all, the earlier a suitable strategy is selected, the sooner the goal of climate neutrality of buildings can be achieved.



General consensus exists around the following steps that make up a successful climate protection roadmap:

1.   Define CO₂ footprint

2.   Increase energy efficiency

3.   Renewable energy supply

4.   Generation of renewable energies on-site

5.   Generation of renewable energies off-site

6.   Use of offsetting programmes as a last resort

Source: World Green Building Council.

In 2017, the World Green Building Council (WorldGBC) launched the “Advancing Net Zero” initiative to help advance CO₂ emissions reduction in the building sector. The aim is to ensure that all new construction projects are CO₂-neutral by 2030, while advocating for all existing buildings to be CO₂-neutral in operation by 2050.

All project signatories commit to publishing their performance data no later than two years after joining the commitment. To this end, the WorldGBC provides a template to help with consistent data collection for each building. In addition, a decarbonisation plan with specific goals and information on the fund’s progress is requested, which can be derived from the building-related data, among other things.

Signatories of the commitment are also expected to disclose information about the implementation of set goals and measures. This ensures commitments made are translated into real action.

The commitment’s guiding principles are as follows:

1.   Measure and disclose CO₂ emissions

2.  Reduce energy consumption through efficient operation and technology

3.  Compensate CO₂ emissions through renewable energy, preferably in the following order (priority in descending order): on-site produced energy from renewable sources, nearby or off-site renewable energy production; or CO₂ compensation programme

4.   Improve accuracy and verifiability of the data collected. Over time, this should be accompanied by considerations of the construction- and building material-related CO₂emissions produced. Another goal should be to reduce water consumption as well as waste production.

Climate Positive (DGNB e.V.)

LEED® Zero (U.S. Green Building Council)

Zero Carbon Certification (International Living Future Institute)

Source: International Living Future Institute.

The International Living Future Institute‘s (ILFI) Zero Carbon Certification claims to be the first worldwide Zero Carbon third-party certified standard requiring projects to fully decarbonise. The self-declared goal is as follows:

“One hundred percent of the operational energy use associated with the project must be offset by new on- or off-site renewable energy. One hundred percent of the embodied carbon emissions impacts associated with the construction and materials of the project must be disclosed and offset.”

Buildings must demonstrate net zero carbon operations based on a one-year performance period. In general, the project has to account for its embodied carbon impact resulting from construction and building material through approved carbon offset programmes. Regarding energy generation, new projects may not utilise on-site combustion. To achieve certification, the project must further be able to show it has achieved embodied carbon reduction in terms of the materials used in comparison to a reference building.

Net Zero Operational Carbon (London Energy Transformation Initiative)

Source: London Energy Transformation Initiative.

In collaboration with the UK Green Building Council and the Better Buildings Partnership, the London Energy Transformation Initiative (LETI) provides Ten Key Requirements for New Buildings to showcase how new buildings can operate at net zero by 2030.

The first requirement is to strive for the lowest possible energy use. Annual energy consumption and gains from renewable energy generation on-site must be measured and independently verified. This must be done annually for the first five years to ensure reliable data is available to fulfil further requirements.

In addition, the CO₂ contained in the materials used and generated in construction processes must be collected. This collected data must be verified by independent third parties post-construction. Reducing embodied carbon is a crucial requirement.

Considering the supply of the project, no fossil fuels should be used for heating, cooling or electricity supply. In addition to reporting on annual CO₂ emissions, it is also important to ensure that on-site renewable energy sources make a significant contribution to covering energy demand. Further, intelligent energy demand response and storage measures should be incorporated into the decarbonisation strategy for new buildings. This also includes reporting on the building annual peak energy demand and discussing with the utility provider.

Finally, a carbon balance calculation should be made. The minimum requirement is for buildings to achieve net zero carbon balance; however, should this not be attainable through required measures such as on-site renewable energy generation or investments into additional off-site renewable energy capacity, then a 15 year renewable energy power purchase agreement (PPA) should be made.

To date, no certified LETI Net Zero Operational Carbon projects exist.

Which certified net zero projects are leading the way? 

Below, we introduce you to a few exemplary projects that have been certified for their net zero carbon performance and innovative efficiency solutions:

• Freiburg City Hall is the largest plus-energy-building in Europe, certified in accordance with the DGNB Climate Positive certification. Among others, the building impresses with its energy-efficient envelope, the use of groundwater in conjunction with a heat pump for heating and cooling, and photovoltaics for electricity generation.
  

Image 1: Freiburg City Hall. Source: DGNB.

• The first building project certified in accordance with the LEED Zero (LEED Zero Energy) scheme are the “Entegrity Headquarters” in the U.S. As a refurbished building from the 1950s, the planners especially focused on maximising user comfort and individual adaptability to the desired indoor climate. On the basis of energy modeling, energy reduction strategies were determined and combined with energy efficiency and solar energy measures to bring the building to net zero. The building has also been awarded ILFI’s Zero Energy certification.
  

Image 2: Entegrity Headquarters, US. Source: USGBC.

• The first net zero carbon building certified under the ILFI Zero Carbon Standard is the Google office building located at Pancras Square in London. Google has committed to strict sustainability goals and their implementation. The building’s operational energy use was reduced, along with a strategic selection of building materials that helped reduce embodied carbon. Finally, through carbon offset programmes the building complex reached carbon neutrality. The long-term goal is to integrate renewable energies more strongly on-site and to reduce the embodied carbon in materials and resulting from construction processes even further, and ultimately to design and construct buildings that bind more CO₂than they emit.