In November we visited Skanska’s development project in Stockholm as part of the Nordic Circularity Piloting Program. The site, a former hospital now being transformed into new housing and offices, is being used as a circular testbed for reusing technical installations.
On the site, two pilot teams are exploring both ends of reuse: The first pilot, with Swegon, Lindab, Demontera and Skanska, examines what it takes to dismantle HVAC products for take-back instead of scrapping them – from inventory and selective disassembly to skills and costs of preparing products for reuse.The second pilot, led by nolla_E together with Skanska, tests how existing HVAC units can be relocated and reused, including moving a unit from this hospital to a project in Uppsala.
The pilot site, a decommissioned hospital building, has stood empty since 2020, after healthcare activities moved out. The city’s plan is to demolish the current building and replace it with homes and offices on the same site. Skanska will build a new, smaller building on the site using climate-enhanced concrete, reuse structural elements where possible and focus strongly on circularity in the demolition phase. This “in-between” phase – with the old building still standing but already planned for demolition – offers an opportunity to test what it takes to reuse technical installations in practice.
Progress at the site
When we visited the site, both pilots had moved beyond ideas into hands-on execution.
On the roof level, the group gathered around an air-handling unit to hear about the progress on nolla_E’s and Skanska’s pilot:
nolla_E had used its optimisation software to model thousands of potential HVAC upgrade combinations for Skanska’s a new city block project in Uppsala, including the option to reuse an existing unit from the Stockholm hospital.
A relatively new (2011) air-handling unit on the hospital roof was identified as a good technical match.
Because nolla_E’s model knows the fan, heat recovery and other key specs, it can calculate whether the reused unit can replace a planned new one without compromising energy efficiency. In this case, the software shows that the reused unit can deliver essentially the same performance as a new product.
The wider Uppsala retrofit is already designed to deliver an unusually strong ~20% return on investment in energy efficiency, well above the ~7% typically seen in such projects. In this context, the reused unit is one element in a broader, high-performing energy concept.
Excited about the concrete show-case of the circular test-bed, the site visit group continued the tour in the building to lower floors to see Swegon’s and Lindab’s products that will be dismantled for take-back. In this pilot:
Skanska had completed both a general reuse inventory and a more detailed inventory on installations, with help from a specialist “reuse inventory” consultant.
Recently renovated rooms containing suitable Swegon and Lindab components (ducts, commissioning boxes, diffusers) had been identified for dismantling and take-back.
Contracts with dismantling company Demontera had been prepared, including instructions on how products should be dismantled, packed on pallets, labelled and handled safely in a former hospital environment.
Dismantling of selected products was scheduled for early December, followed by transport to Swegon and Lindab for quality checks and refurbishment.
One visible enabler on site was Skanska’s use of 3D scanning. The entire building has been scanned, allowing teams to “walk” digitally through corridors and rooms, measure ducts and components and compile lists before going on site – a significant support in large and complex buildings like this hospital.
Learnings and next steps
While the Stockholm pilots are already showing clear potential, the site visit also surfaced several important learnings. One is the importance of starting early enough. Even though the pilots engaged well before demolition, from a building-lifecycle perspective it was still late: many design and permitting decisions were already locked in, making reuse harder to integrate.
Another learning is how demanding selective dismantling can be in practice. In a hospital environment, health and safety and environmental risks require extra precautions. For Demontera, this means additional time on safe access, careful unscrewing, cutting, sorting and packing – all of which is being recorded carefully to understand the real process cost.
Next, the teams will complete dismantling and transport of the selected products to Swegon and Lindab, where the components will be refurbished and tested for air-tightness and current standards. In parallel, nolla_E and Skanska will finalise the business case for reusing the 2011 air-handling unit in Uppsala, comparing it with a new unit once all dismantling, logistics and refurbishment costs are known.
Three key takeaways so far
When asked to summarise their main learnings so far, the Stockholm pilot teams and partners highlighted three themes:
1 - Make circularity part of business as usual
Circular HVAC will only scale if it is embedded in everyday project processes—targets, cost tracking and procurement—not treated as a one-off pilot driven by goodwill.
2 - The coordinator / orchestrator role is missing but essential
Coordinating several manufacturers, demolition firms and logistics is too complex and time consuming for a single person to manage alone. The pilots emphasized the need for dedicated actors that can take ownership of materials and manage the full take-back chain on behalf of property owners.
3 - Legal and responsibility issues are the real bottlenecks
Technically, many products can be reused. The difficult questions are legal and organisational: who guarantees performance after refurbishment, what happens to CE-marking when components are changed, and how do contracts reflect this? Clear answers on responsibility and performance after refurbishment are as critical as the technical feasibility.
Advice for anyone launching a circular technical systems pilot
Lastly, we asked the pilot team what advice they would offer to peers considering their own circular technical installation pilot:
Put ownership and roles on paper early
Decide from the outset who owns the products, who will sell or donate them, who takes responsibility for CE, warranty and insurance, and how demolition and take-back are contracted. Writing this down at the start – even if it later evolves – saves time and avoids confusion when the first ducts are coming down.Use the pilot as an internal training ground
Treat the pilot as a hands-on learning environment. Involve project managers, site teams, procurement and legal teams early to test new ways of working and spark practical discussions on contracts, storage and future reuse models that rarely emerge from theory alone.
Thank you to Skanska, NollaE, Swegon, Lindab and Demontera for the insightful site visit and for pushing circular HVAC from concept into practice in Stockholm.