Title: How insulation works
Headings: Insulation works by providing resistance to heat flow.
Passive Design
How insulation works
Insulation works by providing resistance to heat flow.
Where heat is lost
R-values
How bulk insulation works
Reflective insulation
Thermal bridges

Content: If a material consists of many small pockets of trapped air rather than a large, contiguous volume of air, the ability to transfer heat by convection is also reduced. An everyday example is a feather or fibre duvet. Bulk insulation
Bulk insulating materials such as wool, polyester, glass wool and foam boards work by trapping air and reducing the speed of heat transfer. Reflective insulation
The Acceptable Solution H1/AS1 no longer accepts the use of foil insulation (since 1 January 2017). Retrofitting or repairing foil insulation under suspended floors has been banned since 1 July 2016. Thermal bridges
Thermal bridges, also called ‘cold bridges’, are parts of the building envelope where heat can escape more readily because the building material connects – or bridges – both sides of the building envelope. Examples of thermal bridges include: timber or steel framing in external walls that connect to both the interior and exterior faces of the wall
aluminium window frames that do not have a thermal break
gaps in (poorly) installed insulation. One area of thermal bridging with a high impact on performance is timber framing in walls. In one research study, measurements made of 47 new houses found the average content of timber framing in exterior walls (excluding doors and windows) was 34%.