Independent Network (I.N), G.G.F and the Glazing Industry work to a prescribed acceptable visual quality standard method for inspecting double glazed sealed units. IN uses these visual quality suitability guides to determine a tolerable level of glass appearance in the home.
Based on IN standards and the industry standards (GGF) there are various publications concerning the visual acceptable quality of glass, there are basic rules that need to be understood and accepted to avoid a difference of opinion between our members and the home owner.
A common sense approach needs to be taken and an understanding that modern processed glass is NOT going to be completely flawless.