Varmistavasta

Varmistavasta is a Finnish term that refers to a method of window and door installation where a narrow gap is left between the frame and the surrounding construction. This gap is typically filled with sealant, such as silicone, to ensure a tight seal and prevent air leaks.

In the context of passive house construction, varmistavasta is a key component in achieving high levels of energy efficiency. By leaving this narrow gap, the installer can ensure that the sealant can be applied correctly, and the resulting seal is strong and durable. The use of varmistavasta also allows for better humidification and ventilation control within the building.

The process of varmistavasta typically involves:

- Installing the window or door frame in a concrete or brick surround

- Applying a continuous bead of sealant to the gap between the frame and the surround

- Ensuring that the sealant is set and has cured before proceeding with further construction

- Inspecting the gap to ensure a good seal and making any necessary adjustments

While the terms and the specific details about this process and the requirements for its execution may vary slightly in different regions that build according to the Passivhaus standards, the core principle remains the same: leaving a thin gap for an uninterrupted seal to prevent heat exchange between interior and exterior spaces of a house.

The efficiency of passive buildings, achieving near 100% of their insulation efficiency, would not be possible within the current technological constrains, without precise control over air tight seals and their resulting properties maintained within very high standards throughout a structure.