Seosaeng House sees Studio Weave’s Je Ahn return to his Korean roots

Look carefully at the red-pink concrete soffit at the front of Seosaeng House on South Korea’s eastern peninsula and you will see a recessed steel railing that stretches the length of the elevation, within the almost 1m-deep eave. It could be an expansion joint but it is, in fact, a bar on which to hang dried foodstuffs traditional to South Korean cooking, such as persimmons. The rail is positioned in front of the living room, next to the outdoor kitchen and around the corner from the utility and indoor kitchen.

The outdoor kitchen itself has power, water, a full-width drain to the back and a jet-down floor for barbecuing and fermenting. Beneath the above-ground volumes of Seosaeng House is a basement where all the homemade goods produced on the deck can be stored at a constant temperature for even longer, alongside water and oil tanks in reserve for the blackouts that can happen during the summer monsoon season and can last up to a week.

Much of the new house’s design comes down to this approach, connecting the building to its climate and reconnecting its architect, Studio Weave’s founder Je Ahn, with his South Korean roots. This includes knowing the granular detail and finding ways to accommodate the traditions of the area’s people in their relationship between indoor and outdoor, public and private, architecture and inhabitation.

Ahn effectively left South Korea when he was 14 years old. He won a scholarship to a school in Britain, carried on to university in the UK and, in his words, ‘stayed longer here than he expected’. Soesaeng House is his first project back in the country where he was born and spent his early childhood. It is a family home for his brother, who lives in Hong Kong but who wants to return to where they grew up. For his brother, it is also a kind of preparatory step to re-establishing himself in the community, putting down roots again, socially and psychologically.

The house is designed as a multigenerational home too – for Ahn, his parents and their wider family to gather. In that sense, it resembles the traditional Korean house, with bedrooms and sleeping spaces dispersed around the floor plan and a second living room. The idea is to provide communal spaces as well as spaces for separation.

‘I know the area well, but it has changed enormously,’ says Ahn. ‘The project has been both personally rewarding and anguishing – to work in a different context but somehow not. There are different boundaries. It has made me think more about what I do in the UK – seeing the correlations of why I do certain things.’

The plot is located on the side of a mountain looking out over to the East Sea (Sea of Japan), on the furthest south-eastern coast of South Korea, where the sun rises first and people come to see in the new year. It’s common for people to self-build in South Korea because, Ahn explains, the big house-builders are only interested in high-rise apartment towers in the cities, not suburban or countryside homes. In this case, the plot was owned by a land developer that had split up the site and was selling portions as partially prepared plots. The slope of the site had been removed to make it level, but this had also taken away its character.

The site is approached from the sea-facing side, with the 40m by 20m rectilinear plot rising behind. Ahn’s first objective was to re-establish the site’s connection with the landscape by restoring the slope, building it back by building over and enclosing the levelled foundation work. This lifted the house on stilts – hence all the underground storage.

Visitors by car enter at the lower level, through a garage door that looks dug into the mountain to the left of the site. Alongside is a cascading terrace of huge rounded local river boulders, planted with local species, selected for their hardiness against salty rain and high wind from the sea, including low-lying shrubs and rock plants that will soon take over. Guests arrive via the outdoor stairs in between, while there is another private stair for the homeowners through the timber garage door, leading up behind the outdoor kitchen.

At this upper level, the house rises in three volumes, merging a hillside typology with the traditional Korean courtyard house. The plan is a side-on U-shape. The 1m tiers give every room a view of the sea, either through the house or over the top. Boulders continue to cascade down the restored slope around the house, into the courtyard, which prevents the soil from being washed away in heavy rains.

From a planning perspective, there is a precise formula for countryside houses which determined the building’s footprint and volume. Other than that, the house is designed to be economical with environmental advantages. It uses concrete from a plant 10km away, whereas the timber alternative would have had to come from Canada and be embalmed so extensively with chemicals to comply with the earthquake zone regulations that its character would have changed considerably.

The internal structure is left exposed to minimise finishes and it was all designed to use Euro Form formwork, which is a module that can be bolted together and reused multiple times. Everything within the structure – internal walls, partitions, doors, joinery and kitchen units – is slotted in using timber. The project was entirely built during Covid when it was only permitted to have one trade on site at once. This approach worked well because the joinery company was able to use a 3D scan of the interior to make all the joinery off site with some tolerances. They didn’t need to visit.

Likewise, the cladding is manufactured by a local fake stone company. It had to be masonry cladding to survive the harsh -15°C winters and humid, 32-35°C summers. The design adjusted the company’s largest possible slab using a convex insert to produce a slight 15mm curvature to the panels, which captures shadow and interest. The colour is determined by the soil just beneath the topsoil so the building becomes ‘part of’ the landscape. The dark rounded pavers are sliced volcanic rock from nearby, gravel in between.

The minimal interior kept the costs down too – with it all made out of Lauran timber plywood, typical to south-east Asia. ‘We chose it for its grain, depth, variation and warmth,’ says Ahn. ‘It’s quite cheap. It was widely used in Asia in the 1960s and 1970s, so it has particular connotations. My mother couldn’t understand why we wanted to use it. But plywood is stable in humid environments. Any other option would have been imported from Russia, Finland or Canada. I’ve used enough pale plywood in my work.’

The terrazzo floor tiles, very fashionable in Europe, were another decision Ahn’s mother questioned. The factory-made slabs were also cheap and robust for underfloor heating.

Environmentally, the 980mm-deep eaves prevent solar gain while being narrow enough not to contribute to the strict volume calculations. The trees in the courtyard are persimmons which will grow to 6m tall, with a similar breadth canopy. In summer, the persimmons grow large reflective leaves that will aid shading, but they are deciduous which will be useful for solar gain in winter.

For such a small structure (162m² above ground and three bedrooms), a huge amount of detail has been squeezed into Seosaeng House. The inclusions go on and on – many of them charming. The roof is sawtooth because flat roofs don’t cope well when it rains as much as it can. The whole house is on a small concrete plinth (ie no level access between inside and outside) to prevent rainwater ingress. The heating and air conditioning vents (powered by air-source pumps) are channelled through the timber partitions. Mosquito nets are cleverly incorporated into the glazing frames, concertina-style. The wood-burning stove in the second living space was a request from Ahn’s father to roast his sweet potatoes.

The homeowner entrance is tucked into the courtyard side, whereas visitors leave their shoes on the concrete step in front of the living room, entering through the sliding doors, away from the everyday gubbins of the hallway. Every detail and thought is there to make its inhabitants and visitors feel like they’ve come home, albeit with a world of experience alongside them.