Heat loss through the roof can be up to 30% of the total heat loss throughout the dwelling. This is due to the fact that heat rises. The insulation can be laid out along the ceiling if the attic space is not being used or else the insulation can be placed on the slope of the roof. This is the easiest and probably the most beneficial improvement that can be made to the thermal performance of the dwelling.
Rolls of insulation laid between the joists are the most common method for insulating attics. This not only reduces the heat loss through the ceiling but it also complies with the current building regulation requirements. Rigid insulation may also be placed between the joists to provide a walkway through the attic.
Energy Supplies are registered with the SEI to install attic insulation under the Home Energy Saving scheme.
The pay back period for attic insulation is typically 2 - 3 years.
Attic spaces which are used as a living space must be insulated on the slope of the roof. Typically rigid insulation is placed between the rafters. However, insulation may also be placed on the internal side of the rafters to eliminate any thermal bridges.