Facts about energy efficiency in relation to lofts

  • Emissions from buildings are a major contributor to climate change
  • Loft insulation is one of the most cost-effective and easy ways to make a building more energy efficient
  • Compressing loft insulation at least halves its effectiveness, doubling the heat lost
  • 82% of householders squash their insulation, because they use their loft for storage
  • The only solution to maintain the savings for the insulation is to protect it with a deck that prevents compression.


Governments across the world encourage energy efficiency in buildings, both to help the occupiers reduce their heating and cooling bills, and also to reduce overall carbon emissions. In the UK, this need is particularly acute as Britain has the highest level of fuel poverty in Europe (despite the cheapest energy prices) and 25% of the country’s total carbon emissions arise from buildings. The UK has also set legislation in place to that commits the country to reducing emissions by at least 80% in 2050 from 1990 levels.

Loft insulation is one of the most cost-effective and easy ways to make a building more energy efficient, and many countries have embarked on a programme to retrofit adequate insulation into buildings. In the UK, the minimum building regulations thickness of loft insulation (using mineral or rock wool) is now 270mm, or about 11”, and many new buildings have more than this.

Yet for insulation to work properly, it must not be compressed. Research by the National Physical Laboratory in London showed that squashing insulation from 270mm to the typical joist height of 75mm or 100mm resulted in a performance reduction of 50-60%, thereby at least doubling the heat lost. But compressed insulation is widespread – according to Britain’s largest ever survey of how people use their lofts, carried out by the Carbon Trust and interviewing 6,000 people, 82% of people living in UK private and social houses use their loft for storage. Of these, 78% said their loft was “more than half full”, 65% had boarded their loft and, from the total population, 76% said that using the loft for storage was either “very important” or “essential”.

This is a major problem for Governments and regulators, as they find that their loft insulation programmes simply fall short of the expected benefits. In fact, an analysis by LoftZone of all the academic literature on the subject in the UK has concluded that 28% of the benefit of all deep loft insulation has not been realised, simply because of compression, and that five whole power stations are wasted because loft insulation is squashed and isn’t working properly. Policy makers must therefore assume that if loft insulation is not protected, its performance will be reduced by this amount.

Yet loft insulation protection is easy to achieve, by creating a deck above the insulation which can be used for storage and access purposes. The LoftZone StoreFloor product is the fastest, easiest, way to create a safe deck, and can be installed at the same time as the insulation. StoreFloor is both cost-effective and increases the desirability of the having the loft insulated, since storage space is not lost. In a trial by YES Projects for Insulate Hampshire, free loft insulation plus StoreFloor was offered to low-income households that had already refused free loft insulation alone. The result was incredible, with massive demand from these previously “hard-to-treat” customers. If householders are offered insulation in a way that does not reduce their storage space, then the insulation offering becomes much more attractive.

Watch a short video about why squashed insulation is a major problem