Vertical ground-source heat pumps to a depth of 250 meters, heat pumps for ventilation, recycled aluminum, and the DGNB certifications Gold, Heart, and Diamond. These are some of the initiatives being implemented to strengthen sustainability in the construction of the Water Culture House on Papirøen. In August 2022, the Nordea Foundation contributed DKK 25 million earmarked for investigating and implementing sustainability measures in the project, which is already well underway in the construction phase and therefore subject to a wide range of constraints.
The Nordea Foundation’s Work on Sustainability
All applicants to the Nordea Foundation are required to address how their projects contribute to sustainable development.
Read more about the Nordea Foundation’s work on sustainability (in Danish) on their website:
Mini Guide to Sustainability | Nordea Foundation
You can also download the Nordea Foundation’s mini guide (in Danish) here:
Reality Overtakes the Project
In the spring of 2017, the City of Copenhagen launched the international architectural competition for the Water Culture House. The competition program included requirements related to environmental and climate impact, based on the municipality’s standard regulations Miljø i Byggeri og Anlæg (MBA 2016). Since then, focus on and demands concerning the construction sector’s climate footprint have steadily increased. In January 2023, new legislation came into force requiring all new buildings to document their climate impact through a life cycle assessment. The legislation also introduces progressively stricter limits on CO2 emissions from construction towards 2030, and in view of other initiatives, the requirements are expected to be tightened further.
The Vandkulturhuset Papirøen Property Foundation, which is responsible for constructing the Water Culture House, has therefore—since late 2021 and in dialogue with the Nordea Foundation and the City of Copenhagen—been working to further strengthen sustainability initiatives, both environmental and social. In March 2022, the Nordea Foundation was formally applied to for support of this effort, and in August 2022 the project was awarded DKK 25 million.
DGNB Certifications, Biogas, and Recycled Aluminum
The project focuses on measures that will make both the construction phase and the future energy consumption of the Water Culture House more climate- and environmentally friendly. An initial feasibility study was carried out to screen all conceivable initiatives. In this process, the following stakeholders contributed proposals: Søren Jensen Engineers, Kengo Kuma and Associates, Vilhelm Lauritzen Architects, MT Højgaard, COWI, the City of Copenhagen, the Nordea Foundation, Transsolar, HOFOR, and the Vandkulturhuset Papirøen Property Foundation. Based on this, a number of initiatives were concretized and each proposal’s cost and effect were assessed.
This process has now been concluded, and decisions have been made as to which initiatives can be realized.
DGNB Certifications
The building will be certified with DGNB Gold. This certification is achieved by assessing the construction across six main categories: environmental quality, economic quality, social quality, technical quality, process quality, and site quality, followed by improvements to ensure the project reaches a required score.
The certification demonstrates that the project raises its level of ambition beyond the legal minimum requirements. In addition, supplementary recognitions will be achieved: DGNB Heart, focusing on well-being and indoor climate, and DGNB Diamond, recognizing architectural quality. As of November 2023, no swimming facility has yet obtained a DGNB certification.
The CO2 Footprint of Materials
As part of the DGNB work, a screening of all materials used in the Water Culture House has been conducted to identify where the greatest potential for improvements could be found. The materials used in the largest quantities – and therefore having the greatest impact on the CO2 balance – are brick, aluminum, concrete, and steel. All other materials are also being improved as much as possible within the financial framework, partly by obtaining EPDs (Environmental Product Declarations), and partly by identifying alternatives where reductions in environmental impact are possible. Below is an overview of the changes made to the four most extensively used materials in the project:
Brick. The building’s façade and much of the interior cladding consist of brick. Biogas and green electricity equivalent to the energy consumption from the production of the building’s bricks are being purchased. This results in an additional financial cost of DKK 712,000 and a CO2 saving of -346 t CO₂e (-1.3 kg CO₂e/m²/year).
In addition, brick is a highly durable building material that can last for centuries or be dismantled and reused 1:1 in new construction. The Water Culture House’s handmade, custom-produced bricks are supplied by Petersen Tegl.
Aluminum. In addition to brick, the roof and façade consist of prefabricated roof and façade modules made of aluminum. These are produced using recycled aluminum. Recycled aluminum constitutes 75–80% of the aluminum used in the building. This entails an additional financial cost of DKK 1,270,000 and a CO2 saving of -1,517 t CO₂e (-5.3 kg CO₂e/m²/year).
Recycled aluminum is previously used aluminum that has been remelted and reused. Aluminum does not lose its properties after recycling, and the remelting process saves up to 95% of the energy compared to producing new aluminum. The aluminum is supplied by the Norwegian company Norsk Hydro, whose production is powered by renewable hydropower.
Concrete. The possibility of using green concrete was carefully examined. However, no green concrete has been used in the project, as such concrete is not available in the structural classes required for a swimming facility exposed to aggressive salt and chlorine environments.
Steel. The last material with major potential is the large quantity of steel used in the construction, which forms the structural frame of the building. Steel is the only material capable of fulfilling the architectural vision of the winning competition proposal, with its free-floating truncated pyramids that must also support the heavy weight of the brick cladding, both inside and out. Moreover, agreements to purchase the steel were already in place when the opportunity arose to make improvements.
The steel has a lifespan of more than 100 years.
Images of a mock-up of the building’s façade made of handmade, custom-produced bricks.
Drone images from January 2024 showing the building’s steel framework and the prefabricated roof and façade modules in aluminum.
Process Energy
In parallel with the DGNB certifications, sustainability measures are also being implemented within process energy. Process energy refers to the energy used to operate the entire water treatment system of the Water Culture House, the ventilation of the swimming pool areas, and the heating of pool water. Below is an overview of the measures that have been decided and are therefore being carried out in the project.
Process energy measures being implemented
Heating of outdoor pools. The building’s ventilation system has been upgraded to a ventilation system with a heat pump that utilizes surplus heat from exhaust air. The surplus heat from the heat pumps will be used to heat the water in one of the building’s two heated outdoor pools, Onsen. The water in Onsen is heated to 36°C and is located beneath an open roof structure on the first floor of the building.
Vertical geothermal system. Permission has been sought to establish a vertical geothermal system. This includes 11 boreholes approximately 250 meters deep. Heat from the heat pump will be used to heat the water in the second of the building’s two heated outdoor pools, Dalbassinet. The water in Dalbassinet will be 27°C and located under the open sky between the roof structures on the first floor.
In addition, the potential use of cooling energy from the geothermal heat pump is being investigated. By utilizing the cooling energy, the efficiency of the released heat energy is improved. Moreover, soil cooling can be reduced or even avoided entirely. The specific cooling measures being considered include cooling the cold-water pool on the wellness floor, cooling rooms with electrical panels, and providing supplementary comfort cooling in the association tower and the foyer.
Intelligent heat consumption control. With intelligent control of heat consumption, energy providers have been granted permission to reduce the building’s energy use when needed, preventing the activation of emergency power plants that run on less climate-friendly energy than regular power stations.
Solar panels. It has been decided to establish solar panels on another building to provide solar power—that is, green electricity—for the heat pumps. It has not been possible to implement solar panels directly on the Water Culture House due to architectural requirements for the building’s design. Project development is ongoing.
Process energy measures not being implemented
The following initiatives have been studied and could potentially be implemented, but are not prioritized within the current financial framework:
Reuse of backwash water. It has been investigated whether backwash water can be reused, which would result in significant water savings. However, there are certain risks of adverse consequences when using soft water.
Heat from gray wastewater I. The possibility of extracting heat from gray wastewater using a heat pump has been examined. The measure was deemed too operationally demanding and therefore not pursued.
Heat from gray wastewater II. Another possibility of extracting heat from gray wastewater through a simple “pipe-in-pipe” system, as seen in other Copenhagen swimming pools, was considered. This was assessed as not environmentally or economically feasible.
Heat recovery from harbor water. The option of recovering heat from harbor water has been studied but was evaluated as neither environmentally nor economically viable.
Solar heating pipes beneath the brick façade. The potential of installing solar heating pipes beneath the brick façade has also been investigated but was found to be neither environmentally nor economically viable.
Biodiversity and Social Sustainability
The first step towards reducing the climate and environmental impact of the construction has been the material and process energy initiatives described above. The next step is to further strengthen the project’s social sustainability and explore initiatives that can enhance biodiversity.
There are different definitions of social sustainability. In the DGNB framework, for example, the criteria focus heavily on technical building elements such as indoor climate—including acoustics, noise, air, and light—as well as functional criteria such as meeting places. Others argue that social sustainability relates to quality of life and well-being, while some connect it to equal access, opportunities, and social justice (Stender, M. (2018). Social Sustainability and DGNB).
In the physical design of the Water Culture House, inclusive solutions have already been incorporated to make the facility more accessible and welcoming to a wider audience—for example, through the establishment of flexible changing rooms and pool lifts at all swimming pools. These are isolated examples, as the work on social sustainability initiatives has only just begun. In the coming process, it will therefore be necessary to define and develop the concept further in dialogue with future staff and user groups. The goal is to specify concrete measures unique to the Water Culture House, thereby ensuring an even higher level of social sustainability than the current baseline.
In addition, initiatives related to biodiversity will be considered in the upcoming design and planning of the harbor bath, which will be located along the quay in front of the Water Culture House.
Information on additional initiatives will be published on the Vandkulturhuset Papirøen Property Foundation’s project website as the work progresses.