Passive family home in Koblenz

Building for music and nature: The house in Koblenz is a structure that does not compromise in style or energy efficiency. Energy efficiency, acoustic performance and fire safety all combine in this unique, passive standard family home.

The natural choice for a more sustainable living
Built for a nature enthusiast, focus on sustainability and close contact to the outdoors were of major importance to architect Udo Heimermann:

"The beautiful nature of the Rhine Valley, natural principles and traditional building methods were the inspiration for the house. The organic style was therefore the natural choice," the architect explains and continues: "Emphasis was put on environmental concerns. Building methods and materials such as ROCKWOOL® insulation were used wherever possible to reduce the impact of the building on nature."

To ensure high thermal efficiency and keep CO₂ emission at a minimum, ROCKWOOL insulation was chosen because it is a mostly natural and durable material that can last for generations.


A fire safe concert hall
The owner wanted to create superb acoustics in the living room to give the feeling of being in a concert hall when listening to classical music at home. This was the main reason for the organic shape of the house and became the building principle of the entire structure says the architect.

But acoustics and energy efficiency were not the only concerns. The dome of the house is made of wood so fire safety was an equally important aspect when it came to choosing mineral wool for insulation.

The performance of ROCKWOOL insulation in the presence of intense heat or fire is very important consideration for architects, builders and installers, Moroslav Smolka, Fire Safety Manager at ROCKWOOL International explains:

"When exposed to high temperatures of up to 1000° Celsius, ROCKWOOL mineral wool retains its shape and form and continues to provide thermal insulation, which is one of the vital properties needed for fire protection."


The effectiveness of a circle
The round shape of the house a very energy-efficient building form. The circle reduces the wall area by 13% compared to a square house while covering the same net floor area. This reduces the amount of building material and increases energy efficiency.

"This has a huge positive impact on the use of building materials and energy efficiency. Energy consumption is reduced to an estimated 25% of a normal house due to efficient insulation, high density and an effective waste heat recovery system," explains the architect.

The big windows and the dome roof windows let in as much daylight as possible, reducing the need for artificial heating and lightning and providing a supplement to insulation measures.


The ROCKWOOL group makes the building process easier
The organic form and the dome construction of the roof were a challenge architect Udo Heimermann says but "the high density of the ROCKWOOL insulation material made the insulation material very easy to install and shape on site. So it was the perfect material for the round shape."

Due to the special nature of stone wool, ROCKWOOL insulation can be adapted to even very challenging designs without reducing the materials' high insulation power.

Herwig Fischer from the Energy Design Centre explains:

"When ROCKWOOL insulation boards are placed side by side, the fibres' structure will interlink and prevent cold bridges between the boards. Neither temperature nor relative humidity will at normal operating temperatures have an influence on the insulation."