The average cost to replace windows in a typical unit varies from $15,000 to $25,000. Our technology achieves the same result at 10% or replacement cost. The average life span of aluminum windows is 15 to 20 years. Our retro-fit technology restores them to original, thus providing a further 15-20 years of utility. To prove our technology, we will retro-fit one unit free of charge to prospective landlords.