Hi I live near A railway like really near, the front of the house is prob 5 m away.. it’s Edwardian and currently single glazed we got a quote for soundproofing windows the 40-50pervent noise reduction was 600 per window and the 80 percent was 2000 per window.. I’m wondering if we will regret not going for most sound proofing but it seems so expensive anyone know what 50-60 percent sound decrease is equivalent to?