Grundtvigs Hus

Grundtvigs Hus

Built in 1908, Copenhagen’s historic Grundtvigs Hus was the first building in Denmark to be made with concrete floors. Today, the property is slated to become a first-of-its-kind lighthouse project for green energy systems.

Energy Consumption Reduction
CO2 reductions
Capital Expenditure
Savings on operating expenses
Payback period

Expected project completion: 2025

Copenhagen’s Grundtvigs Hus and the adjacent corner building on Vester Voldgade and Studiesstræde is on its way to becoming a high-performance energy machine. The property will generate, store, and reuse its own energy as a fully electric geothermal-based integrated system, with no connection to district energy providers.

Designed with our own design modules, the integrated energy system will have a total capacity of 430 kW. The system will be comprised of:

  • Geothermal energy storage (36 x 240m boreholes, drilled sustainably by LKAB Wassara AB and HP Borrningar AB)
  • Energy Machines' integrated heat-pump-chillers
  • ClimateMachines high-efficiency air handling units (90% temperature efficiency)
  • Rooftop PV solar panels
  • Energy Machines Control software and cloud-based SCADA platform

The comprehensive energy transformation will enable renewable thermal energy from the subsurface of the earth to be captured and stored in the ground along with surplus energy from inside the building. The stored energy will be distributed via Energy Machines’ integrated ground source heat pump-chiller as heating, comfort cooling, and hot water for the 10.000m2 property. Our unique air handling units enable the recovery of 90% of surplus heat that would otherwise be wasted – with no cross-contamination or mixing between air streams. Rooftop PV solar panels will supply locally generated electricity to power the system.

This energy machine is projected to achieve:

  • 100% net CO₂-free operations  
  • 84% energy reduction
  • 97% reduction in operating expenses  
  • DGNB Platinum certification (on track for completion in 2025)  

To enhance the system's environmental impact, specialists from HP Borrningar AB employed an electric LKAB Wassara AB drilling rig for the efficient drilling of 36 boreholes using a water-powered method. This approach, utilizing Wassara's water-powered drill, presents several advantages. The ground undergoes a less impactful pressurization compared to air, reducing the risk of affecting nearby formations and properties. Moreover, the work environment is significantly improved, as there is no airborne dust. In situations like drilling in residential property basements, where noise levels are critical, water-powered drilling holds an advantage with its lower noise levels.

The project will become a live public showcase for geothermal-based integrated energy systems. The building, built in 1908, is on track to achieve DGNB Platinum certification (Refurbishment), establishing a new benchmark for what is achievable within standing assets. It will be the only refurbishment project outside of Germany and only the 6th total to achieve such a score.  

Along with the building owner, we look forward to welcoming you into the space upon completion to explore firsthand what it means to be an energy machine.  

(1/2) Grundvigs Hus, Vester Voldgade, Copenhagen
(2/2) The corner building at Vester Voldgade and Studiesstræde, Copenhagen

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Technologies used

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