Located in Ho Chi Minh City, the studio looked to the traditional architectural forms of village housing to inform the design of Red Cave, a private residence dedicated to fitness and wellness.
The form of the structure mimics the typical profile of a detached home – a largely rectangular form with a pitched roof.
The exterior walls, roof and windows of Red Cave feature a completely flush finish that allows all of these surfaces to merge into one.
The front of the home is marked by a trapezoid-shaped windowless volume, host to a plant-filled terrace on its roof that is cut into the main volume of the home.
Where not windowless, rectangular, square and circular windows of different sizes cover the adjoining walls of the red-hued exterior across its three storeys.
On the ground level and surrounded by a moat of water, a series of pillars encircle an open-plan, indoor-outdoor area that is dedicated to fitness and exercise while supporting the rest of the structure above.
"The space is built with a specific function but can be used for many different functions, a frame of scene neutral, activated by the user," said the studio. "Mirrors increase the stimulation of activities and exercise in an endless, a continuous, fluid manner."
Geometric openings in the walls, and concrete stepping-stone-like platforms inserted into the ground floor's shallow moat, hint at Red Cave's geometric theme.
A yoga suite occupies the first floor within the windowless volume. Light is instead funnelled in via a large skylight, illuminating the space while retaining privacy.
"We focused more on harnessing the light at the main seat, a terrazzo circle-slab, surrounded by the structurally sloped roof, creating a dark space to absorb the focused light," said 23o5studio.
At the rear of the yoga suite, a large circular opening stretches across the back wall. It also cuts away part of the exterior wall above, forming a sheltered semi-circular balcony for the yoga and wellness area.
The second floor houses the living areas, which are centred around an angular glazed recess and the roof terrace.
Slicing into the pitched roof, the cut-out area is lined with floor-to-ceiling windows that look out to the terrace and beyond to the nearby Saigon River.
"The terrace [is] set up for the host's enjoyment, and relaxation, where they can party, or relax after hours of practice with the other members."
A mezzanine level, which is accessed via a ladder, forms the sleeping area. Meanwhile, an open-plan kitchen and seating area are organised around the angular glass walls.
23o5studio is a Vietnamese practice that works across residential architecture.
Elsewhere in Vietnam, Vo Trong Nghia Architects designed a five-storey home to represent the pottery and ceramic heritage of its location in Bat Trang, while ODDO Architects built a family residence on a backland plot that measures just four metres wide and six metres deep.
The photography is by Hiroyuki Oki.