green building

Green Building Calculator

Self-assess your CO2 footprint and energy costs

Self-assess your CO2 footprint and energy costs

Our green building calculator benchmarks your building against sustainability targets: When will your building cross the Carbon Risk Real Estate Monitor (CRREM) decarbonisation pathway and become a Stranded Asset? What energy costs will you have to pay in the future? Which actions can you take and what are their impacts on your energy consumption?

For instructions on using the calculator, watch the tutorial.


  • How it works?

    Carbon Risk Real Estate Monitor

    The Carbon Risk Real Estate Monitor (CRREM) is an EU-funded research project that develops sustainability goals for the European Real Estate industry. The CRREM goals are not (yet) legally binding but are already widely used as a benchmark in the Real Estate industry. CRREM uses the term decarbonisation path to describe the annual maximum permissible CO2 emissions to limit global warming to 1.5°C by 2050. According to CRREM, the term Stranded Asset describes a property that exceeds this decarbonisation path.

    CO2 emissions

    The calculation only approximates the actual CO2 emissions of your building. The CO2 calculation factors reflect national average values assuming 201 gCO2e/kWh for natural gas, 280 gCO2e/kWh for district heating and 36 gCO2e/kWh for biomass (pellets). For electricity, a year dependent factor (526 gCO2/kWh for 2022) is used to reflect changes in the energy mix, as defined in CRREM. Regional and temporary peculiarities such as the different district heating mix of regional suppliers cannot be taken into account in the calculation. For a more accurate calculation, consult your local utility.

    Energy costs

    The calculation only approximates the actual energy costs of your building. Energy prices per kWh of €0.30 for electricity, €0.10 for natural gas, €0.15 for district heating and €0.10 for biomass are assumed in the calculation. Regional and temporary price deviations cannot be taken into account. Check the prices with your local energy supplier for a more accurate calculation.

    Key performance indicators (KPI) for sustainability

    • The Stranded Asset KPI highlights the year when your property is expected to become a Stranded Asset.
    • The CO2 emissions KPI highlights the area-related CO2 emissions of your building for the reference year
    • The energy cost KPI shows the area-related energy costs of your building for the reference year 

    Option for actions

    There are three options for action to choose from, the effects of which you can simulate. For simplicity, an immediate effect of the selected actions is assumed. Use the sliders to set the scope of each action, showing the associated percentage of energy savings. The savings that can actually be achieved can deviate from this, as it depends, among other things, on the age, state of renovation and the characteristics of your property and its technical equipment.

    • Energy-oriented refurbishment slider simulates the impact of renovation measures (e.g. replacing the façade) and the replacement of your technical building equipment (e.g. installing a combined heat and power plant) on your energy consumption. The percentages shown (20%, 40% or 60%) refer to the energy sources: natural gas, district heating and biomass. Energy-oriented refurbishment has only a minor impact on electricity consumption, which is why savings of 2%, 5% and 10% are assumed for this. 

    • HVAC performance optimisation slider simulates the impact of optimising the operation of your HVAC systems on your energy consumption. HVAC systems are rarely operated with ideal settings. Therefore, it has an energy saving potential of up to 30%. Depending on the condition of your current systems and their configuration, the savings that can actually be achieved may differ.

    • Self-produced renewable electricity slider simulates the influence of an expansion of your capacity of self-generated regenerative electricity, assuming that the electricity consumption is unchanged. Self-generated electricity can come for example from a PV system or a combined heat and power plant.


    Annual energy price increase slider allows you to simulate the impact of different energy price inflation scenarios. The selected percentage represents the compounded annual growth rate of the assumed energy prices projected over the subsequent years.  


    Do you have questions about the Green Building Calculator or would you like to share your feedback with us? We look forward to receiving your email at [email protected]


  • 🟢 Differentiate your building with a Green Building Certificate by TÜV SÜD

    Corporations strive to comply with increasingly ambitious ESG goals. Real Estate plays an important role due to its large environmental impact. A Green Building Certificate assessed and issued by TÜV SÜD makes your sustainability efforts visible and allows you to differentiate your building. We benchmark against green building standards such as BREEAM. DGNB and LEED. Get a Green Building Certificate issued by TÜV SÜD in 3 simple steps:

    Your benefits

    • Learn how sustainable your building is at present
    • Increase the visibility of your sustainability achievements
    • Identify actions that will help you improve the sustainability of your building
  • 🟠 Revitalise your HVAC performance with TÜV SÜD Technical Monitoring

    Heating, ventilation and air conditioning systems (HVAC) account for more than two thirds of our buildings' energy consumption. Misconfigurations in these systems often lead to substantial energy wastage. TÜV SÜD Technical Monitoring helps you discover energy losses in your HVAC system by comparing projected system targets with actual system performance. Enable TÜV SÜD Technical Monitoring at your property in just 3 steps:


    Your benefits

    • Create transparency over your HVAC performance through an independent expert
    • Reduce your energy consumption while keeping your current systems in place
    • Lower your recurring energy costs with a minimal investment
    • Reduce wear and tear of your HVAC systems
    • Reduce user complaints and increase comfort level
  • 🔴 Navigate your energy-oriented refurbishment with TÜV SÜD Climate Action Plan

    Energy-oriented refurbishment can vastly reduce your energy consumption. Possible actions differ greatly in their impacts and required investment. TÜV SÜD 3-steps Climate Action Plan helps you select the right investments that deliver the best return.


    Your benefits 

    • Optimise your CO2 footprint and reach your sustainability targets
    • Reduce your building´s energy consumption and costs
    • Identify the refurbishment actions that generate the best ROI
    • Save money by avoiding ineffective but expensive investments

Next Steps

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