The circular economy house opens up prospects for building the future

The steel-structured Pyörre House, completed for the Lohja Housing Fair, is a bold new kind of home, where efforts have been made to minimize the climate impact during the construction phase and housing. The building’s carbon footprint has been influenced by material choices.

Pyörre House, completed for the housing fair in Lohja’s Hiidensalmi, by Lake Lohjanjärvi, is delightful with its round shape, fresh atmosphere and spacious views. The target is also a model house in a circular economy, where living has the least possible impact on the environment. 

The innovative house is a testament to the fact that living comfort and climate-friendly building solutions can go hand in hand. Efforts have already been made to minimize the environmental impact during the construction phase. The Pyörre House has been built by Aulis Lundell Oy, and the main material supplier for the site is Saint-Gobain Finland. 

The Pyörre-talo project combines our 40 years of expertise and innovations in lightweight systems. We chose Saint-Gobain Finland as our partner because we have had in-depth cooperation for a long time, and I knew their product family was a pioneer in the field of low-carbon construction. 

Leena Lundell, CEO of Aulis Lundell Oy 

A detailed study has been made of the materials used in the building and the climate impact of the site. The assessment method being developed at the Ministry of the Environment has been used in the climate impact assessment. The carbon footprint of the building during its life cycle has been calculated in accordance with the decree of the Ministry of the Environment, which will enter into force in 2025 . Various European circular economy assessment methods have also been tested at the site.

The low-carbon circular economy in the building arises from concrete solutions.  

The most important factors for low carbon and the circular economy are the efficient use of space and the potential for change. These have a direct connection to the need for materials and energy, which in practice make up both the carbon footprint and recyclability.

 The architect of the building, Professor Matti Kuittinen from Aalto University. 

Recyclability and circular economy 

The choice of building materials has been guided by circular economy and recyclability. As much of the material as possible is recycled or suitable for recycling at the end of its life cycle. The most recycled materials are thermal insulation, metal parts and gypsum and concrete products. 

– More than a third of the building components of the Pyörre House are recyclable or renewable. This is the direction the world must go. Buildings need to be put on a diet, consume less of the earth’s raw materials and maximize the use of recycled material. We found that when the idea of ​​keeping a golden thread in design and procurement can really make an impact. We each have to make choices, because only in a circular economy do we promote carbon-neutral construction, Leena Lundell says.  

A total of 22 percent of the site’s building materials are recycled in origin, 15 percent of the raw materials are renewable, and 63 percent are virgin. At the end of the life cycle, as many as 82 percent of materials can be reused or recovered as material or energy. 

Carbon footprint and carbon handprint in a pound 

Material choices affect emissions throughout the building’s life cycle. 

– Materials play a key role in the building’s circular economy. They enable long service life, versatility, energy efficiency and, over time, recyclability. In architecture, material competence will be emphasized in the future, says Matti Kuittinen. 

At Pyörre House, 45 percent of life cycle emissions are caused by the manufacture of building materials. The operational climate disadvantage is about 30 percent, as the vortex’s energy efficiency is excellent. 

The carbon handprint of the Pyörre building, ie the positive environmental impact during the life cycle of the building, reaches almost the level of the carbon footprint of the house. The climate benefits of an estimated 97,200 kgCO2e are due to the recyclability of the products, the carbon stored in the structures and the carbon sinks in the garden and recycled concrete. 

Experimental floor casting in geopolymer concrete 

The vortex house’s carbon dioxide emissions have also been reduced by utilizing geopolymers and alternative binders in the concrete floor of the car room . The floor is cast from geopolymer concrete, the main binder of which is blast furnace slag. Some of the natural sand used as a filler has been replaced by recycled foundry sand. 

The casting carried out in September 2020 was the largest geopolymer casting in Finland in 30 years, and it originated from the Horizon 2020-funded WOOL2LOOP project coordinated by Saint-Gobain. 

Circulation Economy Theme is realized also in the house striking  pihalaatoituksessa , which used in the manufacture of Weber yard of concrete used in the manufacturing process flows within. In addition, biochar has been added to the tiles during the manufacturing phase. 

The share of recycled materials in the floor and yard tiling of the car room is about 40 percent. 

Circular economy building solutions will be available from July 9 to August 8, 2021 at the Lohja Housing Fair, where Pyörre House is number 7.