It seems a miracle that a house in the Örebro area, in Sweden, is still standing in all its beauty, but is almost 100 years old. To understand the story of this house, we need to look back to Sweden in the 1920s.
At that time, energy was becoming dramatically scarce because of the First World War. The government looked at a wide range of options. It tightened the regulations for insulating new buildings. Architects and chemists pondered whether there could be a building material that was as easy to work with as wood, and at the same time strong and insulating, without burning or rotting like wood.

The idea of autoclaved aerated concrete changed the world
In 1923, architect Axel Eriksson fulfilled the dream of many by inventing a new building material: autoclaved aerated concrete (AAC), a mixture of lime, cement, and sand. He hardened the new mixture under high pressure. 
This was the birth of Ytong (formerly: Yxhults ånghärdade gasbetong). And it wasn't long before the blocks became synonymous with a product category and an industry innovator, and the building material conquered the world from Sweden. AAC simplified construction for architects and craftsmen. It accelerated the urgently needed housing construction after the Second World War. Today, anyone who wants to build in a modern and sustainable way cannot ignore AAC.

Resisting moisture and fire for almost 100 years
Coming back to the house which was built in 1930. The property in Örebro was designed in 1930 by Gothenburg architect Ture Svanberg. Over the centuries, the monolithic house (200 mm Ytong) has withstood hot summers and cold winters without any major problems. It has been connected to the city's district heating network for almost 50 years. Energy costs have remained at an expected and acceptable level in comparison with similar houses with different wall construction. It has never been refurbished due to fire or moisture problems.
The exterior and interior plaster is original and has not required restoration. The blocks have stood the test of time, showing no signs of shrinkage or cracking over the years.

Scientifically validated
The durability of AAC is a result of its stable mineral structure. A key mineral component is tobermorite, which is also found in nature and is structurally a chain and band silicate. Studies have shown that the properties of AAC do not change over a very long period, more than 80 years.
In a municipal cultural inventory in 2008 of central parts of Örebro, the house was designated as having cultural-historical value. The national romantic style house was considered to have "great aesthetic and environmental qualities, and maintenance should be carried out so as not to spoil the character of the building".
The Swedish house serves as a testament to the potential of autoclaved aerated concrete for sustainable construction.