Description
The IB VL 33 Bat built-in box is the updated version of the IB VL 12 and is divided into three compartments with a 20 mm spacing. The compartments are accessible via the entrance slit and through the openings in the internal walls. This built-in box is ideal for bats as a summer roost, mating site, and—during mild winters—even as a winter roost. The species that use the box depend on the local area and which bats are already present there.
When only one box is installed per location, it typically serves as a summer or mating roost. The box is also suitable as a maternity roost, but in that case, at least three units should be connected to create a larger interior space. This connection can be made using multiple IB VL 33 units or in combination with one or more IB VL 34 Bat Built-in boxes. This reduces the number of visible entrance slits in the facade.
Suitable as summer, mating, and maternity roost (when at least 3 units are connected) for:
During mild winters potentially usable by:
For bats, the more space available, the better!
The IB VL 33 Bat built-in box can be installed in both new construction and renovation projects. It is suitable for masonry facades as well as ventilated facade systems. The front side of the unit (with the slit) should be flush with the outer surface of the wall. Alternatively, it can be recessed slightly to allow for finishing with brick slips—only the entrance slit will then remain visible. The box can be installed on any facade orientation.
Installation tips:
-
Position the box as high as possible on the wall (aim for optimal height).
-
Keep the flight path to the box clear—avoid planting trees or shrubs in front of the wall, and do not install sunshades or similar elements above the box.
-
Do not place the box directly above doors, windows, or balconies due to possible bat droppings.
-
Avoid placing lights near or on the box—the area must remain unlit.
When multiple boxes are used per location (especially when combined with the Bat built-in Box IB VL 34), they can serve as summer or mating roosts, and potentially as small maternity roosts.
Built-in bat boxes are often hard to reach. Still, it is important to check over time whether the box remains clean inside. Contamination often occurs due to moths or other insects. A long, flexible brush can be used to remove such debris.
Important: Always check carefully that no bats are present before cleaning!
