Paul Smith's flagship store in the South Korean capital is housed in a softly curved white shell punctuated by small circular windows and a bright yellow entrance (+ slideshow).

Architecture studio System Lab designed the fashion designer Paul Smith's first South Korean store for a site in Seoul's densely built Gangnam-gu district, a popular shopping destination filled with luxury brands.

The irregular shape of the building was informed by a number of planning restrictions – building constraints limited the ground-floor plan to 330 square metres, but the client wanted to accommodate larger floors within the upper levels of the building.

"We had to create a concrete shell with maximised floor area ratio within the legal regulations by rounding, cutting or connecting all the edges," principle architect Chanjoong Kim told Dezeen.

"It was very challenging meeting all the requests of Paul Smith when we considered the restricted area, as well as the high-density commercial district surrounding the area."

The voluminous white building expands outwards from the base to accommodate three shop floors and two office levels, which vary in size, shape and proportion. It also includes one basement level, which is the only storey with a rectangular plan.

"The shape of the building needed to be inflated as much as it could be," Kim said.

The curved white facade, made from white reinforced concrete, was cast in carved styrofoam blocks and finished with a semi-gloss paint that covers the joins in the structure.

An arched glazed opening with a luminous yellow surround forms a small display area and entrance in an otherwise windowless facade.

"It was constructed to provide an aggressive gesture towards the road," said the architect.

Signage for the store is displayed on a curved white signpost that emerges like a submarine telescope from a grassy strip to one side of the doorway.

On the other side of the entrance, a garage door opens into an underground car park where up to 14 vehicles can be stacked vertically beneath the shop floor.

A smattering of circular windows run along the ridge of the sloping roof, lighting upper floor office spaces, and the wooden and concrete stairwell that connects the levels.

The studio also designed the interior for the second and third floor offices, while the shop floors were designed by the Paul Smith design team.

Wooden stairs lead from a main office with green stripy carpet, typical of Smith's designs, to a meeting area under the apex of the roof structure.

The space is furnished with a collection of upholstered chairs and has access to an outdoor terrace at the rear.

Photography is by Yongkwan Kim.

Project credits:

Architect: Chanjoong Kim (Kyung Hee University) + Taek Hong (System Lab)
Exterior finishing: Exterior wall - Painting on a sphere, Floor - Stone [THK30]
Contractor: Geo Hyun Construction
Interior: Paul Smith + Core Design
Design Team: Kyunam Song, Hyunsoo Park, Younghwan Kim, Youngjin Cho, Chulmin Ahn