It started in the 70's with the DIYs, click the picture to view the report

• 1970 Harak sen. - how he began
• 1980 Stoll sen. - A master tiler saves energy
• 1991 Daughter Harak - with styrostones - what else?
• 1995 Daughter Stoll - with styrostones - from experience
• 2001 Harak jun. - saves energy like his father
• 2004 Stoll jun. - IT-entrepreneur builds smart