ABC Flats By Isso Architects: Concrete Curves And Communal Living In South Jakarta

Project Info

Project Name: ABC Flats

Location: Jakarta, Indonesia

Architect: Isso Architects

Lead Architects: Wibisono Soegih, Stephanie Tatimu

Lead Team: Arini Zairina Putri

Design Team: Rangga Cakra Birawa

General Contractor: PT. HAGE Primadi Konstruksi

Interior Contractor: Silla Home

In one of South Jakarta’s densest neighborhoods, Isso Architects reimagines compact living through ABC Flats - a co-housing project that transforms just 175 square meters into a layered, light-filled community. Rising quietly within the Cilandak district, the three-story concrete building houses eleven ensuite rooms across three room types, balancing private comfort with shared experience.

Concrete cylinders stack rhythmically, giving the structure its distinct urban presence

Compact living, elevated

Built with an overall footprint of 423 square meters, ABC Flats demonstrates how thoughtful planning can turn spatial limitation into architectural opportunity. The project’s rooftop pantry and communal terrace extend the concept of shared living upward, offering residents a collective open-air retreat amid the tight urban fabric of Jakarta.

A view from above: the terrace doubles as both social hub and skyward retreat

The rooftop pantry extends communal life upward into open air

A rhythm of curves and concrete

From the street, ABC Flats stands apart through its striking facade - a stack of cylindrical forms that introduce rhythm, softness, and motion to the raw concrete surface. Isso Architects uses repetition and curvature not as decoration, but as a design language that humanizes density. The interplay of light and shadow across the curved surfaces changes throughout the day, giving the compact structure a sculptural, almost kinetic presence within the neighborhood.

Curved concrete volumes lend movement and lightness to the compact co-housing block

Inside the stack

The interior organization is efficient yet refined, following three longitudinal bands: stairs, aisles, and rooms. This layout ensures clarity of movement and easy maintenance, with all mechanical and electrical systems neatly consolidated in a central shaft. Curved walls and partially detached railings continue the fluidity of the exterior, allowing natural light to spill softly through the space.

Materially, the design balances the honesty of exposed concrete with the warmth of wood and a muted color palette. These subtle contrasts foster a sense of calm, offering residents both privacy and connection.

Inside, clean lines and warm wood tones balance the texture of exposed concrete

Minimalist interiors offer calm and connection within the dense urban fabric

A vertical courtyard experience

Entry unfolds beneath a triple-height staircase, where wooden flooring, a reflective pond, and a large skylight converge. Natural light filters down through the vertical void, shifting throughout the day to animate the surfaces below. This careful orchestration of light, air, and water gives the small-scale building a sense of generosity - an urban microcosm where the architecture itself becomes a form of community.

A triple-height staircase anchors the interior, illuminated by a dramatic skylight above

Every curve, every shadow is part of a language of restraint and rhythm

Redefining urban co-housing

With ABC Flats, Isso Architects shows how architecture can negotiate density without compromise - turning constraint into creativity, and compactness into a catalyst for shared life. In the evolving landscape of Jakarta, the project stands as both a sculptural landmark and a prototype for the city’s new generation of communal living.

Photo Credit: Ernest Theofilus