The law of 18 April 2013 defines the construction of a building in accordance with the functional needs of a national library of the 21st century, responding not only to the needs of conservation and valorisation of Luxembourg's intellectual heritage, but also to the renewed needs of the public and of future generations.

[1] It does so through legal deposit, as well as by completing its collections through acquisitions of documents that are published abroad by Luxembourgish citizens, authors or habitants, or which are otherwise linked to the country.

The library also manages special collections containing i.e. manuscripts, rare and valuable documents, prints, maps, photos,[12] musical texts[13] and artist's books.

[14] The BnL not only preserves but also studies these collections and regularly publishes its work, such as the 'De Litty' series, which aims to make Luxembourg's musical heritage more accessible to teachers and the younger generation.

[2] Similarly to course of action as a heritage library, the BnL also produces publications and hosts exhibitions, conferences and events in order to valorise its non-Luxembourgish collections.

The BnL must make as much of its collections as possible accessible to a maximum number of people, either through loans, on-site consultations or through the use of modern data transmission technologies.

The BnL coordinates the Luxembourg Consortium and takes care of administration, software management, access and the negotiation of licenses and subscriptions.

[17] In 2017, the government library bibgov.lu was born out of a cooperation between the BnL, the Ministry of the Civil Service and Administrative Reform and the Centre for State Information Technologies (CTIE).