London office Studio Mills has transformed an apartment at an old Kraków monastery into a light-filled family residence.

Studio Mills, founded by twin sisters Jayne and Kirsty Mills, used pale colours, simple furnishings and bespoke joinery to create the minimalist interior for the Polish home.

The designers opted for Douglas fir flooring and white-washed walls to make the space feel bright and airy. They also kept the layout as open-plan as possible.

"The client wanted a modern home you could simply turn the key and walk into," the studio told Dezeen.

"We based the design on the architecture of the apartment; glazing to both sides – plus as the penthouse, it is the highest apartment in the building, so is flooded with light."

In the living area, a full-height library wall made from white lacquered plywood – complete with a rolling ladder – spans one wall.

Here, the designers also introduced some bold colours through furniture and decorations.

A grey sofa contrasts with a mustard yellow arm chair and a circular green sidetable, while a monochrome rug stands out against the light-coloured wooden floor.

"We wanted to maximise the short daylight in winter so we created a palette to reflect the light as much as possible," added the designers.

A kitchen is located at the rear of this space, separated by a small dining table that features chairs in different shades.

In the kitchen, bespoke cabinets are coloured in pale green tones – a shade that is echoed on feature walls in the lounge and dining space.

White marble is used in both the kitchen and the bathroom to create what the designers call a "holistic environment".

There are also brass details throughout the property, including light switches, plug sockets, bathroom taps and radiators.

Studio Mills is based in southeast London. The studio was also behind the Manhattan store for watch brand Larsson & Jennings, which features a cantilevered display counter and a bar serving typical Swedish refreshments.

Photography is by Edmund Dabney.