Describing the renovation as "sophisticated old-fashioned elegance meets modern design", the studio preserved original wooden floors and plaster ceiling mouldings, contrasting them with colourful pieces of furniture dotted about the space.
Visitors to the 114-square-metre Strauss Apartment – which is situated at the corner of the building – enter into a spacious hallway patterned with mosaics, along with a circular hanging mirror and bright red side table.
The hallway provides access to two adjacent living rooms, a kitchen and dining area, a double bedroom and a bathroom.
Although no major adjustments were made to the apartment, YCL installed a doorway with a mirrored framework to connect the formerly separate living rooms and "highlight the sense of space" between the two. Both living areas feature original chandeliers and herringbone floors, and YCL has added grey sofas and a yellow side table.
In the dining area, which is situated next to the living space, the studio designed a custom metal bar that spans three metres and sits opposite the all-white kitchen fittings.
"We strived to design a piece of furniture that would become part of the new design, but also blend with the general area with its long regular lines and create an image of a lightweight, expressive structure," YCL said in a statement.
The red side table in the hallway is echoed by a single dining chair in the same colour, which sits alongside five other white chairs at the bar.
The bathroom features white fittings and a tiled floor that repeats the pattern found in the hallway, and is contrasted by another red wooden chair.
"We wanted to turn the new bathroom into an actual room with lots of light, a big luxurious bathtub, and a place to sit down with a balcony perfect for cooling down after a hot bath," the studio said.
The bedroom contains a built-in closet, parquet floors, and grey walls that repeat the colour found in the rest of the apartment.
"Designing functionally comfortable and aesthetic residential environment preserving the authentic elements of the interior of the apartment, and interpreting classics in a modern light was important to us, as architects," YCL said.
"We managed to form a neat composition of something old and something new," the studio added.
Archiplan Studio also blended old and new elements in its renovation of a villa in northern Italy, while Atheorem used a similarly restrained approach while refurbishing a Berlin apartment that dated back to the 1800s.
Photography is by Andrius Stepankevičius.