IB GZ 07 Swift Built-in nest box (suits UK Brick Sizes)

The Swift built-in box is ideal for both new builds and renovation projects. It is specifically designed to be installed within a wall that has a narrow cavity. The box spans halfway through the outer wall, with approximately 120 mm extending into the cavity. It is important to provide adequate support at the rear of the unit.

If the cavity is 150 mm or more, insulation can be placed directly behind the Swift built-in box, particularly if a heated space lies behind. This allows for uninterrupted insulation coverage and avoids thermal bridging. For cavities around 100 mm, the insulation should be carefully cut around the full outline of the box.

For best results, install the Swift built-in box in the gable end, preferably on the north or east-facing wall, about three courses down from the roofline. This position provides the ideal height and minimizes human disturbance. Keep the flight path unobstructed—avoid placing trees or shrubs directly in front of the wall.

Swifts are colonial breeders, so it is highly recommended to install multiple Swift built-in boxes together. Maintain at least 40 cm spacing between units. No nesting material needs to be added. It is advised to install a minimum of one box per new dwelling—for example, in a 30-home development, 30 Swift built-in boxes should be included.