Alex and his partner Dan supplied approximately 14 custom made energy efficient HEAT-Gate replacement windows for our townhouse. the build quality of the windows is excellent, the energy savings over the past year has been noticeable. an additional important consideration for choosing By Installer Windows was the necessity to match the appearance and style of the existing windows, which they did perfectly. now one year after having the windows installed, they look great, are easy to clean, and have proven to be very energy efficient.