Tough goals yield results in the fight against global warming

In the Focus area: The Planet (the environment and the climate), the overall goal is net-zero carbon emissions by 2030 at the latest. Preventing global warming is among the highest priorities for both Castellum’s operation and the world in general. The Earth’s population continues to increase, and resources must be sufficient for more and more people. That is why this area is completely fundamental to Castellum’s sustainability efforts.

Focus area: The Planet


Castellum will responsibly and efficiently reduce resource use and carbon emissions that cause global warming.


  • 15% in energy savings per square metre in 2025, compared with the 2015 index.
  • Energy savings of >1.5% yearly in the like-for-like portfolio (properties under administration for two years).
  • Net-zero carbon emissions and 100% non-fossil fuel energy by 2030.
  • 100% of all vehicles to be non-fossil fuel powered by 2020.
  • 1% water conservation per year in the like-for-like portfolio.


  • 15% savings (8) cf. 2015 and 12% savings (saving: 8) in the like-for-like portfolio.
  • 85% (77) less CO2 emissions from property management. (Scope 1 and 2) since 2007. For monitoring of Scope 3, see Environmental and climate data.
  • 95% (96) renewable energy.
  • 100% (86) non-fossil fuel powered vehicles.
  • 13% (3) water conservation in the like-for-like portfolio.

More efficient energy use

Castellum works continuously to reduce energy use by optimising operations and investing in energy-efficient technologies. Over the past year, 93 developments comprising MSEK 82 were implemented for the purpose of enhancing efficiency. Energy use within the Group is systematically monitored and then analysed. The measures implemented are prioritised in order of greatest potential for enhancing efficiency.

Expansion is under way for Castellum’s own portal for online property monitoring, enabling values relating to operation, alarms, elevators and entries to be tracked. This project saves energy and time, and creates customer benefits in the form of better services through preventive measures. At present, 385 properties representing 2,852,000 square metres are connected to the portal.

In 2020, the normalised energy consumption for heating and property electricity in the like-for-like portfolio decreased 12% year-on-year. The efficiency enhancements are due in part to active work to reduce energy use in Castellum’s buildings, in part owing to the pandemic – which has entailed lower capacity utilisation in our premises, and thus less need for energy – and in part to milder weather in 2020 compared to the preceding year. Heating use decreased 10% in 2020, while electricity use decreased 5%. Since 2007, energy consumption has decreased by a total of 37% per square metre.

The goal of 100% non-fossil fuel powered vehicles has been fulfilled and thus all vehicles – service cars, carpool vehicles and company cars – used by Castellum are either electric or run on biofuel.

Castellum’s heating consumption of 50 kWh per square metre can be compared with the industry average, which uses the Swedish Energy Agency’s reference value for heating premises of 117 kWh per square metre. This means Castellum’s buildings are 57% more energy efficient than the Swedish average for these premises.

Target and outcome, energy consumption per sq. m.

The actual change in the like-for-like portfolio was 11%, non-degree day adjusted. Castellum began systematically measuring energy consumption and heating in 2007,
which is why it is utilised as a comparison year.

Carbon emissions, property management

(Scope 1 & 2 market based)

The actual change in the like-for-like portfolio was 11%, non-degree day adjusted. Castellum began systematically measuring energy consumption and heating in 2007,
which is why it is utilised as a comparison year.

Solar cells on the roof generate added value for AFRY

Castellum’s “100 on Solar” initiative is one of the Nordic region’s largest investments in solar cells, which means that nearly one hundred solar cell installations will be constructed on Castellum properties through 2025.

One of the initiatives is the AFRY office in Solna, where a 255-kilowatt installation covering 2,500 square metres of roof went into operation in 2020.

“As consultants in sustainability and sustainable solutions in buildings, we want to practice what we preach. That is why it is a great pleasure to be able to have this exchange with Castellum, contributing our knowledge as regards solar cell installations,” says Kaia Eichler, Sustainability Manager Business Area Buildings at AFRY.

AFRY is a major societal stakeholder that advocates for legislation concerning the imposition of requirements in projects that promote more sustainable energy supply.

“The issue of sustainable entrepreneurship has increased markedly over the last several years, and especially in 2020. For us at Castellum, it is a tremendous feeling to really have worked out a project that is sustainable and good for AFRY, the environment and the economy. We are looking forward to more exciting customer projects that will push us into new challenges and solutions concerning sustainable property management and project development in the near future,” says Hanna Björklund, Account Manager for AFRY at Castellum.

100 on Solar

Castellum started the Nordic region’s largest solar cell installation in 2019. Since then, the company has constructed 39 out of its target of 100 large solar cell installations.

Distribution of carbon dioxide emissions
Distribution of total energy consumption

Increased share of renewable fuels

Of Castellum’s total carbon emissions, 6% can be directly influenced by oil, gas, and vehicles (service, company cars and carpool vehicles) (Scope 1); the remaining 94% – purchased energy such as district heating and electricity – can only be influenced indirectly (Scope 2).

To reduce emissions, work is under way to phase out fossil fuels; currently four oil furnaces are still in operation.

Approximately 13% of Castellum’s customers are responsible for their own heating and 23% for electricity on the property. A total of 6,181 kW of solar cells have been installed on Castellum’s properties, equivalent to a total of approximately 43,267 square metres of solar cells. Thirteen large solar cell installations were built in 2020.

Castellum’s use of district heating means that its carbon emissions are dependent on the fuel mix used by the district heating facilities. At present, Castellum purchases from 29 district-heating facilities, which represent 93% of the Group’s total emissions under scopes 1 and 2. Castellum is in dialogue with the district heating suppliers with the highest carbon emissions per kWh in order to influence these suppliers to reduce emissions. The transfer to green district heating with renewable fuels is ongoing and currently amounts to 48% of district heating suppliers.

During 2020, scope 1 and 2 carbon emissions decreased by 34% per square metre; since 2007 they have decreased by 85% per square metre. The increase is largely due to an increase in emissions from district heating suppliers during the year. Of Castellum’s total energy use, 95% is non-fossil fuel.

Since 2001, only green electricity has been used in the Group.

Reduced amount of waste

Castellum has long worked actively to reduce the amount of waste that goes to landfill by offering household waste sorting facilities. Monitoring the work is complicated by several sanitation companies being hired, only a few of which can report follow-up in terms of weights. In addition, tenant operations differ, which means their needs for waste management differ as well. Statistics are currently obtainable from 41% (27) of the sanitation companies and Castellum is working actively to increase the amount of available data. The statistics include waste from buildings managed by Castellum, but not waste from projects or construction contracts.

Water consumption

Castellum utilises water from the municipal water system, monitors consumption and takes measures to reduce it.

In 2017, Castellum adopted a target of reducing water use per square metre in the like-for-like portfolio by 1% per year up until 2030. Conservation in the like-for-like portfolio was 13% year-on-year.