I did extensive research prior to deciding to purchase my windows. The windows have made a significant difference in heat loss. They are low maintenance. The installers were polite and efficient and installed the windows professionally to insure there is no heat loss. As can be expected with any job this large there was a situation needing to be addressed. The company took my concern seriously and rectified the situation in a highly satisfactory manner. The windows are amazing and i would highly recommend talking with this company if you need new windows. they sell a high-end window.