According to the BRE, approximately 4% of heat vents though a uninsulated loft hatch. Hardly anyone in the UK currently has a properly insulated loft hatch. This means that the average household is needlessly paying about £50 per year on their heating bills.
Modern building regulations require retrofitted loft insulation to achieve a target U-Value 0.16 W/m²K, which can be achieved with 270mm of mineral wool quilt. Yet an uninsulated or inadequately insulated loft hatch causes a disproportionate performance penalty on the entire installation. This is owed to an effect known as the “calorific boulevard”:
- The loft hatch area of the home is the second warmest part apart from the airing cupboard.
- Often situated above the hall, landing and stairs means that warm air vents “eagerly” away though the hatch, caused by the chimney stack effect drawing, like a fire chimney flue, warm air out of the house and into the cold loft.
- The air pressure can actually lift a loft hatch, causing even greater venting of warm air and an audible rattling of the hatch.
It is therefore very important to insulate homes properly, i.e. creating a complete “tea cosy” around the inhabited building envelope. Even the smallest of gaps create draughts, and even the smallest of draughts quickly become very expensive.
HatchThatch squeezes into place and is held in place by velcro strap either on the hatch itself or (for hatches with ladders) on the joists around the hatch. The skirted edge forms an effective draught seal with the surrounding insulation while the pillow itself puffs up to fill the space neatly and achieve a high insulating value.