The interactive CO2 calculator for buildings provides climate and energy-relevant information for all Swiss residential buildings. It is possible to estimate for all buildings how much CO2 is emitted under standard conditions. This creates transparency around climate and energy policy in the buildings sector and contributes to achieving Swiss climate targets. Under Switzerland's long-term climate strategy, the country's building stock should have net-zero CO2 emissions by 2050.
In Switzerland, the building stock accounts for around a third of the country's CO2 emissions. Reductions in this area are key to achieving climate targets.
Under «CO2 emissions for buildings (SIA 380/1)» on the federal geoportal, you can obtain an estimate of the CO2 emissions for every residential building in Switzerland. These are calculated for standard heating and hot water demand.
Federal geoportal:
The calculation is based on the previous day's input data from the Swiss Federal Statistical Office's Federal Register of Buildings and Dwellings (RBD, see below). These data are not up-to-date everywhere and do not contain sufficient information on building renovations.
The interactive CO2 calculator allows users to find out for each building how a change of energy source – for example from natural gas to a heat pump – or a building refurbishment can reduce CO2 emissions. Any data entered are not saved. It is important to know that the standard values shown here (SIA standard 380/1; 2016) for CO2 emissions do not necessarily reflect the actual consumption values and also do not replace a building energy certificate from the cantons (GEAK). A building's actual CO2 emissions can deviate from the calculated value depending on user behaviour, effective occupancy, the weather and any refurbishment work carried out. The information provides an estimate for standard conditions and does not constitute official or binding information.
How can CO2 emissions be reduced?
Heating with renewable energy: The most effective way to reduce CO2 emissions is to heat a building using renewable energy, for example a heat pump, solar heat, wood or district heating. The Swiss building stock has overall high CO2 emissions because the majority of buildings are still heated using oil and natural gas.
Building energy refurbishments: Refurbishing the façade, roof, cellar or windows helps to reduce CO2 emissions and energy consumption. The cantonal building energy GEAK certificate provides a standard for specialists to assess the quality of the building envelope and overall energy efficiency of the building's utilities, and to calculate its CO2 emissions. GEAK is a standardised national certificate for assessing the energy status of buildings and planning refurbishments.
Improving climate and energy data
The Federal Statistical Office FSO maintains the Federal Register of Buildings and Dwellings (RBD), which serves as the authoritative national information system for buildings. Some new RBD data have been publicly available since April 2022, including climate and energy data for buildings. There is unrestricted access to the RBD for statistical, research and planning purposes in the climate and energy sector.
The RBD was originally set up using data from the 2000 census. It is kept updated on the basis of information recorded by the building authorities for all construction projects requiring a permit, such as new buildings, conversions or demolitions. However, changes in heating systems or energy source are not systematically recorded as there are considerable differences in this area among the cantons and communes; changes are not always reported to the competent authority. As a result the RBD data on heating systems is not entirely up to date in all areas.
The communes and cantons are required to provide up-to-date data for the RBD (Art. 5 RBD). The FSO also strives to continuously improve the quality of climate and energy data by means of secondary data, for example from combustion installation controls, energy certificates (GEAK, Minergie) and subsidy programmes (Building Programme). Going forward, it is crucial that the RBD data remain up-to-date and give an accurate picture of the heating systems used in buildings.
Role of building owners
The CO2 calculator and the building data maps on the federal geoportal help to make the climate and energy data in the RBD more accurate. Building owners are called on to ensure their local authority has the latest data on their property. The map on building emissions helps the responsible authorities at communal, cantonal and federal level meeting the requirement to update the data.
Have your own building data updated
As a building owner, you can help to keep the climate and energy data in the Federal Register of Buildings and Dwellings up to date.
If you renewed your heating system more than half a year ago, the information on which the CO2 calculator is based may no longer be up to date. In which case, please contact the building office in your local authority with the relevant documents (invoices and photos). If you renewed your heating system less than six months ago, please give the authorities time to update the information. They must provide this data in accordance with the Ordinance on the Register of Buildings and Dwellings (RBDO).
Instructions for updating your own RBD data:
Questions and answers
Where can I find the interactive CO2 calculator?
What data does the CO2 calculator use to estimate the CO2 emissions value?
Why do CO2 emissions calculated according to the standard value (SIA 380/1) differ from the actual CO2 emissions?
How is the standard value (SIA 380/1) determined?
How can energy-related refurbishment be taken into account in the CO2 standard value?
What is the difference between the CO2 calculator and the national greenhouse gas inventory?
How have CO2 emissions for the entire Swiss building stock changed in recent years?
What is the difference between the CO2 calculator and the cantonal reporting on CO2 emissions in the buildings sector?
What is GEAK?
What is the difference between GEAK and the CO2 calculator?
Can I download the data for my property or mortgage portfolio?
Is the CO2 calculator freely available?
The interactive CO2 calculator to simulate refurbishments for a specific building in Switzerland can be found under «CO2 emissions for buildings SIA 380/1)» on the federal geoportal. By clicking on a coloured point, you can bring up the information on the given building. Here you will find the link to the CO2 calculator and can simulate how the CO2 emissions value would change were the building to be refurbished or the heating system replaced.
Information on the CO2 map on the federal geoportal:
The CO2 calculator is based primarily on data from the Federal Register of Buildings and Dwellings (RBD). In addition to the heating system (type of energy/heat source), information such as the type of use, heated area, year of construction and altitude and topographical location is included. Buildings heated with renewable energy receive a value of zero for CO2 emissions because, as in Switzerland's internationally agreed greenhouse gas inventory, only direct emissions from building use are considered (so-called 'Scope 1', without electricity 'Scope 2' and grey emissions in building materials 'Scope 3'). This means buildings that are heated with district heating are also currently classed as having no emissions.
Information on the Federal Register of Buildings and Dwellings:
Informationen zur Aktualität der Heizsystemdaten im GWR je Kanton:
Standard values are not the same as the actual CO2 emissions values. A building's actual CO2 emissions can differ from the calculated value depending on user behaviour, occupancy, the weather and any refurbishment work carried out.
The CO2 emissions calculated according to the standard are an expected value for a building category of a given construction period, taking into account the energy sources for the heating and hot water with standard occupancy. These standard values are calculated according to widely recognised Swiss standard SIA 380/1. The climatic conditions at the building location are also taken into account in accordance with SIA climate data (nearest of the 29 MeteoSwiss climate stations). The calculation is also weather-adjusted, meaning that annual weather variations that can lead to strong fluctuations in energy demand (and thus CO2 emission) are not taken into account.
On the CO2 emissions map on the federal geoportal, you can click on a coloured point marking a building and so access the 'Object information', where you will find the interactive CO2 calculator for that building. This allows you to simulate refurbishments and heating system replacements and to determine potential CO2 savings. Unfortunately, in the current version of the CO2 map, information on refurbishments cannot yet be directly taken into account. However, soon in future it will be possible to enter energy-related renovations in the RBD. Reliable – i.e. detailed and standardised – data can be obtained if the refurbishments have been given the GEAK cantonal building certificate. This applies to any future refurbishments as well as those that have already taken place.
The national greenhouse gas inventory determines the actual CO2 emissions for the entire buildings sector in Switzerland and does not estimate the standard values for individual buildings, as the CO2 calculator does.
CO2 emissions for each sector are calculated using the annual total energy statistics of the Swiss Federal Office of Energy SFOE. National emissions are calculated from the use of fossil fuels to provide heating and hot water in buildings. This 'top-down' approach generates accurate values for each sector. The national greenhouse gas inventory shows emissions for the buildings sector from 1990 to the present. The greenhouse gas inventory shows that the buildings sector emitted 10.4 million tonnes of CO2 in 2020, or 24% of Switzerland's total greenhouse gas emissions.
Information on Switzerland's official national greenhouse gas inventory:
Changes in greenhouse gas emissions from buildings are influenced in particular by the weather. For some years now, there has been a downward trend in building emissions, despite the fact that energy reference areas have steadily increased. Thanks to improved insulation standards, refurbishments and the fact that oil heating is increasingly being replaced by natural gas and non-fossil energy sources, the greenhouse gas intensity of building stock has decreased significantly. However, the majority of buildings in Switzerland still have oil or gas heating. To achieve the climate goals of the Paris Agreement, Switzerland needs to drastically reduce its use of fossil fuels.
Under the CO2 Act, the cantons are required iged to report to the federal government on the development of CO2 emissions from buildings on their territory. However, it is difficult to allocate national emissions in the buildings sector according to the greenhouse gas inventory to the individual cantons, as there is often insufficient energy data available for the cantons. To meet the legally required reporting, a majority of cantons have therefore developed a standard method. On the one hand, this standard method relies on available data bases such as the Federal Register of Buildings and Dwellings RBD. Moreover, it supplements missing data with a building stock model and surveys. Some cantons have good data at their disposal, especially when measured energy consumption is available. In such cases, they apply their own methodology based on this data.
Emissions for the individual cantons have been reported since 2016. Cantonal building stock emissions established in this way reflect the cantonal conditions with regard to existing construction periods, building categories, occupancy, climatic conditions, weather, refurbishment status and energy source mix.
In the medium term, the aim is to base the information for reporting on cantonal CO2 emissions from the buildings sector directly on the RBD. The cantons are required to keep the RBD up to date (RBD Ordinance, Article 5) so that it can serve as a robust source of information for climate and energy policy, in conjunction with the transparency provided by the CO2 calculator.
Information on official cantonal reporting:
The cantonal energy certificate for buildings (GEAK), which is standardised throughout Switzerland, is an energy and climate policy instrument of the cantons. It is used to assess the quality of the building envelope and the overall energy efficiency of the building services, calculates the direct CO2 emissions of a building (Scope 1) and is used to plan refurbishments. The GEAK can essentially be applied voluntarily; however, in some cantons, it is mandatory when there is a change of ownership or in order to receive a grant to improve energy efficiency. The Confederation is working towards making the GEAK label visible in the RBD and in the federal geoportal at some future date.
Information on GEAK:
GEAK looks at the specific details of an individual building, while the CO2 calculator makes an estimate using RBD input data. A GEAK certificate is only issued by a certified GEAK expert, who records all relevant data during an inspection. The building owner provides the consumption data for heating, hot water and electricity for the period of at least three years, if these data are available. Using the GEAK online tool, the expert calculates the GEAK and records this in an official four-page document, and possibly writes a report advising on refurbishment. GEAK also calculates CO2 emissions according to SIA standard 380/1 (2016). The standardisation applied is set by the Conference of Cantonal Energy Directors.
Information on GEAK standardisation:
Normierung des GEAK (PDF, 865 kB, 01.03.2023)(available in German or French)
The data on the CO2 map on the federal geoportal can be downloaded:
All RBD data that are publicly available can also be downloaded (Link) or obtained via the web service of the Federal
Statistical Office FSO.
The CO2 calculator is an open-source tool developed for the FOEN by Wüest Partner AG. It was widely used as part of the regularly conducted PACTA climate tests for the Swiss financial market in 2020 and 2022 to test the climate compatibility of property and mortgage portfolios (PACTA = Paris Agreement Capital Transition Assessment). On request, it can be obtained as an R script from the FOEN. You can find the method description under 'Documents' below. It will most likely be further developed for the next PACTA climate test in 2024, after which it will again be available.
Contact address:
Links
EnergieSchweiz: Energieeffiziente Gebäude
(in German, French or Italian)
CO2 calculator as an R script, Climate and financial markets:
Dokumente
Methodenbericht 2024 zum erweiterten CO2-Rechner für Gebäude (PDF, 1 MB, 10.12.2024)Schlussbericht. Im Auftrag des BAFU (available in German)
Last modification 07.11.2024
