Heat loss in a single-family home is not always visible at first glance. Sometimes you only notice the symptoms: one room is cooler, you can feel a clear draught near the window, the panes fog up more often, and heating bills exceed the household budget. Before you decide on a costly energy audit, check where your money is most likely escaping. In most cases, heat escape is not the fault of an outdated architectural design, but of workmanship details: broken insulation, worn seals, poorly fitted joinery, or simply insufficient parameters of an old window. Where to start? Simple diagnostics Start with a basic inspection. Walk through the house and carefully check the joints between different building elements. Focus on roof windows, external doors and the area around the entrance to the unheated attic. Cold zones and draughts: If you feel a clear chill near the window frame or in a corner of the room, it may indicate an insulation problem. Condensing water vapour: Of course, vapour on a window is often the result of cooking and lack of ventilation. However, if water regularly condenses in a specific spot around the roof window frame, it indicates a thermal bridge – the wall surface at that point is much colder than the rest of the room. Mechanical condition: Check whether the sashes close with slight resistance, whether the handle works smoothly, and whether the seals are not hard or cracked. Critical points – where heat escapes 1. Leaky windows and doors (installation is the foundation!) Even a window with the best parameters on the market will not do its job if it is not correctly connected to the wall or roof. For vertical joinery and doors, so-called three-layer installation is recommended (tighter inside than outside). It reduces the risk of heat escape and dampening of the thermal insulation layer. The lack of a specialised flashing and insulation around the frame can ruin the parameters of even the most expensive window. 2. The roof and roof windows Physics is merciless – warm air rises, hitting the roof directly. Roof windows work in extreme conditions (rain, snow, wind, scorching sun). That is why their construction is crucial. The FAKRO windows in our range are equipped with advanced glazing units, e.g. U41 and P50. The U41 unit brilliantly reduces heat loss, while P50 additionally enhances safety, acoustics and features a coating that makes cleaning easier. These solutions are combined with thermoPro technology, which supports thermal comfort at every time of year. Remember, however, the Uw parameter (heat transfer coefficient for the whole window). The FAKRO FTU-V U41 window achieves a fantastic result of Uw = 1.1 W/m²K, but if we use the dedicated Thermo sealing flashing during installation, we lower this parameter to just 1.0 W/m²K! 3. Uninsulated attic entrance This is an often forgotten detail. If the loft ladder hatch is thin and leaky, heat from the corridor will easily "escape" into the unheated attic. When designing an energy-efficient home, you should choose a ladder for special tasks. Our range includes the FAKRO LWT Super Thermo models, which have a thermally insulating hatch as thick as 80 mm (U = 0.48 W/m²K) with a triple seal system. For the most demanding, we recommend the version certified by the Passive House Institute. "A good window is the foundation, but it does not work in isolation from the roof. It is a system of connected vessels – the final success consists of the glass, insulation around the frame, the Thermo flashing and the quality of the installation itself." Everyday protection – habits matter Reducing energy loss is not only about replacing building materials. It is also about daily habits during the heating season: Short and intensive airing: Instead of tilting the window open for two hours (which deeply chills the walls in the recess), open it wide for a few minutes. The air will be exchanged and the walls will stay warm. Temperature management: A bedroom needs a much lower temperature than a bathroom. Overheating the house does not increase comfort, but drastically raises bills. Automatic ventilation: To avoid fogging of the panes, the house must "breathe". FAKRO windows are equipped with automatic air vents that dose fresh air and automatically limit its flow during strong gales. Summary – how can we help you? If your home loses heat faster than you can warm it up, it is time to act. Instead of replacing individual elements "blindly", choose proven systems. At VENA DACH we have a full range of reliable FAKRO roof windows, flat-roof windows and loft ladders. We will help you choose glazing units and flashings with the best parameters, deliver them to your site and carry out professional installation while maintaining the continuity of thermal insulation.
