Research into the acoustic transmission of open and closed windows.

This report presents the findings from a set of laboratory measurements undertakenas part of a contract let by the Department for Environment, Food and Rural Affairs toinvestigate the performance of residential windows in their open and closedconditions and to provide additional guidance on other factors affecting the level ofinsulation.The overall aim of the study is to provide rigorous guidance on the acousticalproperties of residential facades allowing for the requirements of natural ventilation,through either open windows or background ventilators. The guidance is intended tobe of particular use at the planning stage for residential developments; where it canbe combined with appropriate acoustic criteria to indicate the scope, wherenecessary, of noise mitigation works.The insulation of an open window has been generally accepted as being 10-15 dBAalthough the precision and dependence on associated factors, such as opening style,open area and window size, are not readily available. A programme of laboratorymeasurements have been undertaken by the Building Performance Centre at NapierUniversity on behalf of the Department for Environment, Food and Rural Affairs, inorder to quantify the sound insulation provided by a variety of window types, openingstyles, areas of opening and ventilator device