We uncover the invisible. Systematically. The construction of large housing estates and XXL industrial halls brings many sources of error and risks. Trust our many years of expertise in leakage detection and Blower Door testing. Your advantage: You save yourself unnecessary stress with investors and builders.



Only an airtight building can ensure a pleasant and even indoor climate. As an important principle for the planning of airtightness, the principle of "a continuous dense building envelope", also called "pin rule" applies. Only what is clearly planned, can later be carried out airtight by contracting trades. We support you reliably from planning to implementation.



What is a building thermography? A method for the visualization of heat radiation. To detect leaks following the Blower Door test, we check the building envelope with a thermal camera. The modern infrared measurement technology enables us to identify weak points even in hard-to-reach places. This service is certainly included!



An airtight building envelope prevents drafts, odors, increases soundproofness and lowers energy costs. Therefore, the planning of airtightness belongs into experienced hands. With us you get a reliable quality control with the help of a XXL Blower Door test, leak detection and test report for your building. Contact us now!














Special tests

Fog test

With the Blower Door fog test we can detect even the smallest leaks during negative pressure and excess pressure. Our modern fog machines depict the various flow paths in individual areas or complete rooms. Even in hard-to-reach places, potential targeted leaks can get detected.

Door Fan test

With this room-tightness test (Door Fan test), we can check whether your rooms are suitable for the installation of a gas extinguishing system or an inerting system. These systems prevent a fire even before it is created. With these valuable findings you facilitate the fire protection planning and later commissioning of such systems.

Holding-time calculation
for gas extinguishing systems

The measured data of the Door Fan test is required to calculate the holding-time of a built-in gas extinguishing system. For this, it is not necessary to carry out a test-flooding in your building and thus disturb the construction site process. Our proven holding-time calculation according to DIN EN 15004 / ISO 14520 gives you security as an operator of gas extinguishing systems.

Window and door
measurement system

In order to determine joint permeability on components in XXL format simply and exactly, we check all connection joints according to the Window and Door Measurement System which is patented by BlowerDoor GmbH. This joint tightness test of component openings is mandatory today to meet the requirements defined in DIN 4108-2. In the calculation, the joint passage coefficient of the connection joint between two components is determined. In this way you can safely avoid the appearance of drafts near windows and doors.

Radon Rn50 test

Sometimes radon-containing air enters the building and increases the radon concentration in the interior. Some building materials and water can increase this effect. Radon increases the risk of lung cancer in humans. We measure the radon by negative pressure entry rate and determine the expected annual mean concentration. For guaranteed safety right from the start.

Bau.Tools Blower Door test

This test method, which can be used all year round, enables exact location of leaks and airflows through Blower Door and thermography. Even the slightest temperature differences can be quickly located and visualized. Thanks to the patented sequence analysis, defects in the building envelope are reliably detected.

Leak test: system floors

Uncontrolled air in lecture halls, conference or training rooms quickly causes discomfort, unwanted noise and heat loss. Even in these cases, our experts measure the air exchange rate according to DIN EN 13829 and professionally record potential leaks in the system floor.

Leak test: ventilation ducts
of HVAC systems

The energy efficiency of a ventilation system depends to a great extent on its tightness. Leakage on HVAC systems is reliably detected with the leakage test according to DIN EN 12599: 2013. It should be done as early as possible in the construction phase to prevent uncontrolled air ingress and contamination in clean rooms, laboratories and containments.

Tightness test: fire doors (DIN EN 13829)

You are planning economic renovation measures for existing fire doors? We carry out their leakage test in accordance with DIN EN 13829 or ISO 9972. The Blower Door differential pressure method with which we determine the leak rate Qd in this case is again revolutionary. Our proven system provides you with accurate values which are guaranteed not to vanish.