One of the main threats to the conservation of the lesser kestrel (Falco naumanni) is the loss of its traditional nesting sites, which consists mainly of old rural buildings. This has been alleviated by the construction of new infrastructures (known as ‘primillares’) using bricks and concrete blocks. The objective of the project has been to develop and validate the use of precast concrete pieces for the construction of these new primillares. These constructions are completely removable (except the base) and can be transferred to another location if the kestrels decide not use them. These aspects have been demonstrated through the construction of 5 primillares since 2016 (3 in 2016, one of which was moved in 2017, and 2 others in 2018). Their design has been improved over time, which has helped to reduce the weight of the pieces by 50%. As a result of the project, and to increase its replicability, we have defined 3 technical solutions for creating primillares in a great variety of sites. These technical projects have been made available on the MInisterio website to all those interested in this type of action (https://www.miteco.gob.es/es/biodiversidad/planes-y-estrategias/primilla...).