Delivering sustainable systems
Andy Swift, sales and operations manager for Iso-Chemie, says that the sealing of windows and doors using sustainable foam tapes is a viable solution to secure energy efficient buildings.
Changes to Part L of the Building Regulations, which came into effect in 2023, place the emphasis on stricter standards and compliance procedures around energy and ventilation performance, contributing towards a roadmap to a net zero carbon future and properties designed and built in-line with stricter carbon emissions targets.
Specifically, to ensure continuity of the air barrier, window and door units have to connect to the primary air barrier and the frames need to be taped to surrounding structural openings using air sealing tape.
Part L has been welcomed, seeing requirements for improvements in air tightness, forcing it from 10 air changes per hour down to eight air changes per hour and also U values on windows shifting from 1.6 to 1.2wm2 k/H. This places an onus on using energy efficient sealant solutions and the requirement that the window frame should be linked back to the wall with an air-tight tape.
Undoubtedly, building regulation changes are moving the fenestration industry closer to the requirements of the Future Homes Standard for dwellings. This standard, which comes into force in 2025, is designed to deliver buildings which are zero-carbon ready and achieve world-leading levels of energy efficiency.
The uplift in Part L of the regulations includes a requirement for new homes to produce around 31% less CO2 than current standards and a 27% reduction of emissions from other new buildings, including offices and shops. By 2025, when all aspects of the Future Homes and Buildings Standards come into force, the Building Regulations will inevitably become even more strict, requiring new homes to produce almost three-quarters less CO2 when compared to current standards.
This all comes against a landscape where evidence points to doors and windows as the main source of energy inefficient properties. Heat will always find the fastest exit as it comes up against the ‘A’ or ‘A+’ rated window, and invariably this emanates from the 10mm or so expansion gap left around the window following fitment. This is normally left empty, but some amount of spray foam can be injected to fill the void before a silicone trim is applied for a smart looking finish.
Doors and windows account for almost a quarter (21%) of the total air loss in the average house, and when the joints between walls, floors and ceilings are added, the figure can be up to 50%. In most homes, heat losses are overwhelmingly replaced by artificial heating rather than through solar energy or internal warmth, which means reducing domestic heat losses is paramount in the battle to reduce energy consumption.
One way to achieve this is the use of expanding foam sealant tapes such as Iso-Bloco One, which sit between the window or door frame and the wall structure. This one tape fulfils three applications: providing defence against driving rain from the outside, offering thermal and acoustic insulation and creating an air-tight seal internally.
A big advantage of these tape solutions is in the application process. Products like Iso-Bloco One are applied to the window before installation, meaning that windows can be easily installed from inside the building, avoiding the need to use time consuming and costly external access systems like scaffolding and ladders. What’s more, the expanding foam contours to any shape or material to form a seal, creating a neat joint between the door/window and the fabric of the building, keeping your homebuyers warm and happy.
As sustainability remains key to current and future building projects, we will see energy-saving foam tapes grow in importance as effective solutions for sealing window and door frame expansion joints and gaps in houses in pursuit of attaining the Future Homes Standard among other objectives. It’s simply a matter of taking a fresh look at better ways to seal in energy and designing in these products.
