Attic Insulation

House showing heat loss through walls, roof, floors and windows. What we loose without insulation: gaps around doors and windows  25%; roof 25%; walls 25%;floor 15%; windows 15%.


To ensure that an acceptable minimum level of fabric insulation has been achieved, the average U-values of individual fabric elements should not exceed those set out in the table below.

 Maximum average elemental U-values (Elemental Heat Loss Method):

Fabric Elements New Buildings & Extensions to Existing Buildings (W/m2K) Material Alterations to, or Material Changes of Use of, Existing Buildings (W/m2K)
Pitched roof, insulation horizontal at ceiling level 0.16 0.35
Pitched roof, insulation on slope 0.20 0.35
Flat roof 0.22 0.35
Walls 0.27 0.60
Ground Floors 0.25 -
Other Exposed Floors 0.25 0.60

Attic Insulation

If you are looking for a place to start improving your homes energy efficiency, attic insulation is number one. This is one of the easiest and quickest areas to make a difference in your energy costs as 25% to 30% of heat escapes through the roof and the attic is generally an easily accessible area. The energy savings would be approximately 25% over the life of your home and the insulation would have paid for itself in two to three years. The type of attic insulation required depends on a number of factors including, whether it is a new home or an existing home, is the loft a usable space, the depth of the rafters etc. These factors are then taken into consideration in our recommendation for the most appropriate insulation required.

Attic Insulation by John Farrell Insulation, Waterford Insulation
Our tip: Insulating your home properly can reduce your heating and cooling needs by up to 30%