Replacement windows at Grade II listed community building/library

The main feature is 40 long windows around a circular structure, which are rapidly deteriorating. Some of the windows are cracked and the frames corroded resulting in loss of heat and poor ventilation. We wish to replace all the windows to save energy bills and ultimately make the Library more sustainable.Funding will pay for the purchase and fitting of two new window units, one of each of the two sizes and designs represented in the library. We want to do this as a pilot project to ensure the plans are viable.We will then start fundraising to replace all the other windows over a two year period.. We will install Crittall Windows, galvanised and polyester powder coated in standard RAL colour; double glazed using 16mm 4-8-4 krypton gas filled, toughened units.