I used Internorm windows, supplied by NeuFenster for my new house. The windows are fine, but the service I have received from Imre and his team is awful. One of my doors arrived with broken parts. They refused to honour the problem as a warranty claim, even though their own technicians proved it was a manufacturer's defect. It has remained broken and inoperable for 6 months, and I have yet to have it resolved. I am an architect in Toronto who specializes in sustainable homes. I have dealt with bad suppliers before, but this is a new low. If you are considering using Neu Fenster or Internorm, message me directly and I will share my story and refer you to other, superior window suppliers. You don't buy the window, you buy the supplier. Don't be fooled by the attractive product. These windows are paperweights without proper service.