Earlier this year Slovenian firm OFIS Arhitekti transformed three baroque houses in Ljubljana into an apartment block with a secret courtyard, which is featured in this third movie from our series about the studio's work.

Located in the city's historic centre, the three buildings had most recently been used as the offices and bookshop of a publishing company, before OFIS Arhitekti were brought on to combine the spaces and create twelve new apartments.

Providing daylight for each apartment proved difficult so the architects added glass elevations around the existing courtyard, which they then converted from a storage area for air conditioning units into a small garden for residents.

"Since the court is very narrow and enclosed from all sides, the main concern was to provide as much light as possible to become a form of internal garden," said the architects.

Behind the glass, rows of arches with stone pillars provide traces of the original architecture, while the street-facing elevations are restored to their original condition.

The movie was produced by Carniolus and follows one about an Alpine holiday hut and another about a social housing block inspired by hayracks.

Other projects by OFIS Arhitekti on Dezeen include student housing inspired by wooden baskets and an apartment with staggered floors.

See all our stories about OFIS Arhitekti »

Photography is by Tomaz Gregoric and Jan Celeda.

Above: level 1 plan - click above to see larger image

Above: level 2 plan - click above to see larger image

Above: attic level 1 plan - click above to see larger image

Above: attic level 2 plan - click above to see larger image

Above: north section - click above to see larger image

Above: south section - click above to see larger image

Above: east section - click above to see larger image

Above: west section - click above to see larger image

Above: sun diagram - click above to see larger image