The project contemplates the reuse of part of the old industrial warehouses of Can Casacuberta. The need to build a new building independent of the complex to house the service areas was obvious. Thus, the existing warehouses could continue to be free and diaphanous to solve, with simplicity and efficiency, the arrangement of the furniture and the library activities. A covered porch, which acts as a joint between the two buildings, solves the accessibility problems of the complex.

With the expansion, the Can Casacuberta-Espai Betúlia Library now has 4,800m2 and provides the opportunity to offer all the library services and become a cultural centre of reference in the city of Badalona, both in the promotion of reading as in encouraging creativity through words. The Library Service of the Provincial Council of Barcelona has overseen the definition of the programme and equipment until the rehabilitated set on the industrial buildings erected in 1907 is put into service. The Badalona City Council (Josep Massot of the Urban Planning Department and Habitatge-Millora Urbana and Joan Main of the Department of Culture) is the property that, with several interruptions, has contracted the works in several phases. Poch and Moliner carried out a first rehabilitation that reaches half of the buildings. In 1996, the Municipal Institute for the Promotion of Employment (IMPO) commissioned Antonio Sanmartín G. de Azcón with the project and construction management of the library equipment. In 1999, Millora Urbana hired ASZ archuts. S.L. for the completion of the works. The first public library in the city of Badalona was founded in 1929. In 1966, the Library Network of the Barcelona City Council arrived in Badalona with the inauguration of the Popular Library of Sant Anastasi. From the 1950s to the 1970s, the population of Badalona grew. The modernisation and automation of the Library Network began in 1992. Some statistics from the year 2000 indicate 260,000 library visits for a population of 210,000 inhabitants, 50,000 users, 180,000 loans and a total fund of 75,000 books. Espai Betúlia is a facility linked to the Can Casacuberta Library, its mission is to promote the dissemination of words and letters in a very broad sense and their interrelationship with the rest of artistic expressions. Espai Betúlia will have a clear cosmopolitan vocation: it must be a window open to the world that brings us closer to the literary and oral expressions of the world's cultural mosaic. The structure of cast iron pillars and lattices supported the wooden trusses. The project replaces these trusses with asymmetrical trusses supported on riveted latticework. The trusses arranged in an accordion are fixed to each other at the ends and allow the openings to the north-west and south-east to form. The glass is vertical. Light is the sum of cold and warm, and direct radiation is cut off before reaching the work surfaces. The cast pillars only support the roof. The newspaper library of the intermediate level rests on thin legs in the rhomboidal voids of the concrete slab and let in the light. They are also technical equipment (light, air, acoustic improvement, data...). All surfaces of ucume wood, spruce and galvanised sheet are perforated. The concrete roof has been form worked on reeds to avoid bounces. The soil is continuous magnesite with high surface hardness. The roof is finished in zinc. As authors of the project, we add our recognition to the excellent provision of Construccions Sabater and the industrialists who intervened. Especially to Juan López who was the tailor who flattened and sewed the library's geometric zinc mantle.