Hanoi, Vietnam

Category:            Private Homes
Year:                2025
Architects:          Inrestudio 
Lead Architect:      Kosuke Nishijima 
Design Team:         Nguyen Thi Bich Thao, Nguyen Phuong Thao, Nguyen Phuc Nguyen, and Khoa Van Trung GeneralContractor: HLC 
Client:              Private
Photographers:       Trieu Chien 

100 Windows is a multi-generational residence for two generations and three family households — the parents’ generation and the families of two sons — on a riverside site in the suburbs of Hanoi, Vietnam. The site occupies a transitional landscape approximately 30 minutes from the city centre: formerly agricultural, it is now a patchwork of residential plots and rental industrial facilities, neither fully urban nor rural, and expected to change significantly in the years ahead.

Rather than treating this uncertainty as a constraint, the design takes the indeterminate context as a long-term parameter, producing a building designed not for its current surroundings, but for whatever those surroundings may become.

The client brief reflected the dynamics of a multi-generational household. The two sons’ families and their parents had previously lived in central Hanoi but sought a quieter setting better suited to the parents’ later years. The brief required a central living and dining space for hosting guests — including large gatherings such as Lunar New Year celebrations — and a family lounge on the uppermost floor where members of all three households could gather independently.

The entrance and stairs were to connect to the upper floors without passing through the main living area, allowing household members to circulate freely regardless of activity below.

In response to the program and the site, the building wraps itself in what the architects term a “loosely defined double skin.” Unlike a conventional double-skin facade — two parallel layers with a continuous cavity — this enclosure varies in section. In some areas, it reads as a fully detached outer wall; in others, it thickens to incorporate storage and ancillary functions within its depth. Distributed across this skin are nearly one hundred apertures of varying size, depth, and position, giving the project its name.

These openings ensure consistent access to light, air, and views regardless of how the surrounding landscape evolves. Viewed from outside, the irregular placement of the apertures makes the interior layout illegible, preserving the privacy of a building with high visibility across an open site.
At ground level, interior and exterior dissolve into one another. Full-height sliding glass doors connect the living and dining areas directly to the rear garden; when fully opened, the threshold between inside and out effectively disappears.

Floors are finished in Vietnamese basalt stone, continuous with the exterior paving. The entrance and stairs are positioned at the centre of the plan — a configuration that also responds to the narrow, deep plot typical of Vietnamese residential development — allowing family members to reach the upper floors without passing through the main living areas.

The upper floors are enclosed within the double skin, maintaining distance from the surrounding landscape. Bedroom clusters on the second and third floors are organized as continuous circulation loops without dead ends, to accommodate flexible use as household needs evolve. Ceilings are left as exposed concrete; upper-floor surfaces are finished in compressed bamboo, a locally available material with inherent termite resistance. The fourth floor accommodates a dedicated family lounge shared by all three households.

The primary structure is a reinforced concrete frame. At the client’s request, ceiling soffits are left exposed with an inverted beam system, making the structural logic visible from within. Exterior surfaces are differentiated by floor: the ground-floor walls are finished in exposed aggregate concrete, chosen for durability and the visual weight it lends to the base; upper floors are rendered in stucco in a terracotta tone, echoing the red-tiled roofs of the surrounding residential buildings.

The project’s primary environmental argument is longevity. A building optimised for its current context risks obsolescence as that context changes; one designed to remain functional regardless of how its surroundings evolve carries an inherently lower lifecycle burden. The double-skin envelope also functions as a passive thermal buffer, moderating heat gain in Hanoi’s humid subtropical climate, while the distribution of openings across multiple orientations supports cross-ventilation throughout, reducing reliance on mechanical cooling.

Primary interior materials — Vietnamese basalt stone and compressed bamboo — are locally sourced.

At a social level, the project proposes a spatial model for multi-generational cohabitation relevant to conditions now common across many urban contexts: rising housing costs, ageing populations, and the need to balance shared family life with the independence of individual households.

The building demonstrates that these requirements can be met within a single architectural volume without spatial compromise, and that such an arrangement can support a more durable and sustainable pattern of living.