Xella’s BIM department not only develops structural designs for large‑format systems such as Silka Tempo and Ytong Panel, but also provides expert technical advice. The Solna 6 project proved especially challenging. Located next to the Baroque Carmelite monastery on St. Adalbert’s Hill, and an avenue of protected mature ash and oak trees, the complex had to comply with strict heritage conservation rules requiring traditional plaster finishes.
A Monolithic Wall Used as Insulation
Conventional two‑layer wall systems could not support the weight of thick cement‑lime plaster. Instead, Zieliński proposed a monolithic layer of Ytong EnergoUltra+ blocks—typically used as structural walls—as thermal insulation for a 20 cm reinforced‑concrete wall.
The resulting 60 cm‑thick façade improves energy performance, increases thermal mass, and allowed the architects to eliminate air‑conditioning from the design.
“Pleated” Façades Among Mature Trees
Rather than flat walls, JEMS designed gently curved, folded façades that blend seamlessly with the surrounding greenery. Two buildings, arranged in C‑ and U‑shaped layouts, were carefully placed between existing trees, with an underground garage designed to avoid damaging the roots. The complex includes 90 premium apartments with generous layouts and ceiling heights of 3–4 m.
Traditional Plaster on Ytong Walls
Due to the weight of the required plaster, adhesion tests were conducted using Bolix on Ytong EnergoUltra+. The positive results led to detailed design guidelines. The Ytong insulation layer forms a self‑supporting wall up to four storeys high, later supported by the floor slabs. Special connectors transfer wind loads to the concrete structure, and Ytong lintels were used above openings.
A Non‑Obvious Application That Earned Recognition
“The final result fully met the expectations of both the client, OKRE Development, and the architects,” says Zieliński.
Completed in 2024, Solna 6 received the 2025 Greater Poland Voivodeship Architectural Award – winning both the main prize in the “Multi‑family Residential Building” category and the Grand Prix.
The jury praised the project as “a new piece of metropolitan fabric with its own identity, yet appearing as though it has always belonged here.”
Fotocredit: Maria Kot, JEMS Architekci