Canadian architects Office OU have been announced as winners of South Korea's international competition to masterplan a National Museum Complex (NMC) in the new Administrative City Sejong.

Choongjae Lee, the city’s administrator, has vowed to build “the world's most beautiful and liveable city” through investment in architecture, technology, urban planning and design and environmental sustainability.

The design contest was held to select a vision for a complex containing five museums: a National Design Museum, National Architecture and City Museum, National Archives Museum, National Digital Heritage Museum and National Children Museum. A number of smaller cultural institutions, which have yet to be decided, will be spread throughout the complex at a later date.

Office OU were selected to design the project ahead of 80 rival entries – four of which joined them on the shortlist – from 26 countries around the world. Their concept, called ‘Sejong Museum Gardens', was developed in collaboration with Junglim Architecture as the local architect of record.

The masterplan for the 190,000sq m (2 million sq ft) site uses the palace architecture of Korea’s Joeseon Dynasty as a template, merging this with a diverse natural landscape of rice paddies, wetlands, forests and riverbanks. The museums will be differentiated using changes of scale and varied responses to the natural topography.

In a statement, the studio said: “The architecture does not strive to be iconic in itself, but instead acts as a frame or vessel for landscape, drawing it into a set of courtyards and forecourts. Each museum's identity is reinforced by thematic links to an associated landscape.

“For example, the productive orchard landscape that characterises the Children's Museum invites kids to play and explore the space. The Archives Museum will be set within a mountainous topography, fostering an appropriate sense of seclusion and security. The Architecture Museum is defined by hard landscaping with a distinctly urban feel, relating to the city’s developing retail and arts district across the Che Creek.

“In naming the project Sejong Museum Gardens, the garden is recognised as a vital link between culture and nature. Our hope is that the project can give the people of Sejong – and South Korea – a place to understand and nurture this relationship.”

The competition jury – which included a number of acclaimed Korean architects and academics, and Christopher Sharples of US studio SHoP Architects – praised the project’s “exquisite control of space,” as well as “the spatial relationship between nature and built form, which is successfully anchored in human scale.”

The organisers of the competition hailed the masterplan as “a world-class cultural complex that will be on par with Berlin's Museuminsel, Vienna's Museumsquartier and Washington D.C's Smithsonian museums.” A budget and timescale for the project has yet to be revealed.

The NMC is intended to reflect Sejong City's growing political and administrative importance. The municipality was established in 2007 and opened in 2012 in a bid to create more balanced national development away from the capital Seoul. It is now home to 36 government agencies and over 300,000 residents.

Office OU will now develop more detailed designs for The National Children's Museum, the Museum Complex's Central Storehouse and Central Operations Centre. The first phase of the project, comprised of the five museums, is set to be completed by 2023.