The new National and University Library of Ljubljana building (NUKII) will be a symbol of knowledge and culture as well as an archive for historical and national heritage that constitutes a precious legacy in Slovenia. It will be a historical building setting a new course in the "books" of the nation. The project for the new library claims for an architectural proposal to present a unique building. The new library will become a reference in Ljubljana’s urban fabric of international architectural relevance linked to other unique libraries throughout the world.

The building is to be constructed above roman ruins which have to be preserved. Therefore the proposal consists in constructing a transparent shell which both protects and reveals the roman ruins.
A large dome of crossed metal beams is constructed over the ruins and completely frees the space of any vertical structural elements. At the same time it creates a transparent platform (podium) that allows continuous, direct views into the ruins from the surrounding streets as well as from the ground level of the library.
Further, a structural facade is proposed to eliminate the need for any central vertical elements (pillars) and creating by these means, large open areas in the centre of the building. The structural facade rests on the dome podium in a natural flow of load bearing forces that are oriented towards the periphery. The design of the facade is inspired by the V shape of a standing book and is directly linked to the type of programs that are behind it. The concept is the creation of a gradient façade that reacts to the privacy degree of what it conceals. The NE and SW corners of the building are more dense (larger number and smaller scale of diamond / double V shapes) responding to the more private areas (working, storage and technical areas) while the central area on the SE corner is more open relating to the main public areas of the building (free access library areas, multi-purpose hall, and other library public areas). This proposal is also based on a bioclimatic planning strategy that directly connects design and energy efficiency. The facade is a natural sun-shading system maximizing energy gains in the Fall-Winter period and minimizing energy gains in Spring-Summer period, by simply working with density and depth variations. The gradient facade can be considered as a 3-in-1 element that naturally combines the programmatic, structural and bioclimatic concerns.

The plan geometry of the building responds directly to the urban condition of the site plot layout. The core of this basic plan geometry is marked by a central void inhabited by the system of wide public stairs that connects the different levels and lead us to the winter garden like terrace on the last floor, which offers an overwhelming view of the castle and the city.