Circular economy in practice: nolla_E’s pilots promote thereuse of HVAC systems across the Nordics

Image: Kotka Concert Hall / Kotka

Buildings are responsible for about 40% of global carbon dioxide emissions. In office and commercial buildings, technical building systems are typically the second-largest source of material-related lifecycle emissions after the structural frame (Talteka 2025). Because of this, buildings and their technical systems play an important role in reducing climate impact.

nolla_E is part of the Nordic Circularity Piloting Program, which tests circular economy solutions in real buildings. The program includes several pilot projects, and nolla_E is involved in two of them: one in Kotka, Finland, and one in Uppsala, Sweden.

Kotka: improving energy efficiency with existing systems

At Kotka Concert Hall, owned by Kotkan Julkiset Kiinteistöt Oy, nolla_E has used its

software platform to analyse and re-engineer the building’s energy flows. The software identified a set of practical measures that improve energy efficiency without major renovations or new materials.

The ventilation system is currently being refurbished. One existing air handling unit will be dismantled and recycled, while another will be relocated and modified for reuse. Its energy performance will also be materially improved. This project shows how existing technical equipment can be reused to save both finances and emissions.

nolla_E’s method looks at the building as a whole. Instead of focusing on a single solution, it combines several complementary measures that deliver both economic and environmental benefits.

Sweden: reusing equipment from a demolished building

In Sweden, nolla_E works together with Skanska Sweden and and a property owner in Uppsala. Air handling units from a hospital being demolished in Stockholm will be reused in a new multi-purpose building in Uppsala. The goal is to demonstrate that technical systems can be safely dismantled, transported, and installed in another building in a cost-effective way.

One important finding from the project is related to cost estimation. At the moment, the costs of demolition and reuse must be calculated manually. nolla_E is developing a new feature for its software that will enable automatic cost calculation in circular projects. This will make future reuse initiatives faster, easier, and more efficient to plan.

Toward more resource-efficient construction

Both pilot projects support nolla_E’s mission to reduce the carbon footprint of buildings and to promote solutions that are both climate-friendly and economically viable.

Building energy systems hold significant untapped potential. When energy flows are re-engineered and existing equipment is reused wisely, emissions can be reduced substantially, and investments often pay back within only a few years.

Projects like the Nordic Circularity Program demonstrate that circular economy practices in building services are both feasible and profitable. They also support nolla_E’s commitment to Finland’s Green Deal for the Circular Economy in Construction, which aims to increase the reuse and recycling of building systems as part of low-carbon construction.

nolla_E continues to work with its clients and partners to develop data-driven, resource-efficient solutions that make low-carbon building a reality.