A staircase doubles up as a bookcase inside this renovated apartment in Barcelona by Croatian architect Eva Cotman (+ slideshow).

Eva Cotman, who is based in Barcelona, re-planned the interior to accommodate a young couple, who requested a more open-plan layout.

"The project objective is to try to maximise the functionality of the space," said Cotman, "but at the same time to not lose the identity of the neighbourhood and materiality of the existing building."

The architect began by removing all non-loadbearing walls to create a large living and dining room along one side of the space, then added a new bedroom, bathroom and walk-in wardrobe at the back.

An old suspended ceiling was removed and then every surface was painted white - including the exposed brick walls and timber ceiling joists - to create a blank canvas for the new occupants.

The combined staircase and bookshelf is at the centre of the plan and leads up a new mezzanine guest room and storage area. This staircase also functions as an informal seating area.

For lighting, the architect used bright red cables to string bulbs around the ceiling joists.

We've featured several apartment renovations in Barcelona, including one with mosaic floors and one with furniture that folds out of the walls. See more architecture and interiors in Bacelona »

Photography is by Eva Cotman and Maria Ceballos.

Here's a project description from Eva Cotman:

Raval Hideout

This project sets out to alter and improve an apartment situated in Raval, the Ciutat Vella district of Barcelona. An area used to be known for its nightlife as well as the insecurity, El Raval has changed significantly in recent years, and has become one of the touristic attractions in the centre of the city. Today it is home to many bars, restaurants, museums and art galleries, making it a popular neighbourhood among young professionals and students alike.

The clients are a young couple with a very active social life, enjoying fully all the cultural activities that Raval offers. In defining the new use of space, in accordance with the client's needs, much attention has been given to maximise the entering of daylight and the visual interrelationships between the different parts of the house, each with its own identity. The aim was to give the occupant various possibilities to move from one space to another, to create diversity inside the apartment as well as to enable the clients to enjoy the diversity of the neighbourhood where they live.

The project objective is to try to maximise the functionality of the space for the new and contemporary use by the owner, but at the same time not to lose the identity of the neighbourhood and materiality of the existing building. The economic aspect was an important part of the project – it had to be a low-cost project done in a relatively short-time execution.

The apartment was previously 'cleaned': the walls were cleaned from cast, the cast ceiling was removed and all non-loadbearing walls were removed. The apartment wooden ceilings, as well as brick walls, are painted white to be a blank base for the activities of its future occupants.

The heart of the house is around the library, which separates the dining room from the built-in closet and, at the same time, joins the kitchen, dining room and the living room; it is an all-in-one element: staircase, bookshelf, closet and bench. The staircase leads to the small gallery located on the top of the closet, and is a space with a guest bed. This gallery also helps to access the storage, which is located above the kitchen and the entrance area. It is a compact apartment with multifunctional elements to provide flexibility and adaptability to different needs, in other words, a 'mini-space' with a 'maxi-functionality'.

Architect: Eva Cotman
Location: Barcelona, Spain
Project area: 40sqm
Project year: 2013
Constructor: Dolmen Reformes