Itaúna House in Brazil adds a green annexe to modernist Oscar Niemeyer residence

Nestled between a rare pocket of tropical landscape and a vibrant (albeit metropolitan) urban fabric in Rio de Janeiro, Brazil, Itaúna House emerges as an edifice of modernist nostalgia. Originally designed as a compact residence by Brazilian stalwart Oscar Niemeyer, the home and its original ethos have now been reimagined by Siqueira+Azul Arquitetura, evolving into a layered composition of spaces that toe the threshold between structure and nature.

Founded in 1986 by the Brazilian architect Lia Siqueira, Siqueira+Azul Arquitetura has been a defining force in the landscape of contemporary Brazilian Architecture, operating between Rio de Janeiro and São Paulo. The firm specialises in residential architecture, commercial projects, interior design and furniture design, weaving a philosophy that integrates built environments with their natural landscape. With Itaúna House, they have expanded on this approach, crafting a residence that embodies both spatial dynamism and material harmony.

The intervention unfolds as an architectural choreography—three independent volumes connected by fluid pathways, staircases and subtle transitions that seek to upend how one would conventionally traverse these spaces on the outside. The heart of the transformation lies in the interplay of levels, wherein each space is thoughtfully crafted to evoke a sense of discovery. A suspended leisure annexe extends above the pool and garden, appearing to hover over the concrete masses, while the existing structure is redefined by vertical and horizontal thresholds that frame both internal experiences and external vistas.

As one moves through the house, a dynamic sequence of interior spaces unfolds. The original main blocks, once confined, now breathe through large pivoting panels supported by an intricate iron mesh framework, allowing light and air to weave through effortlessly. A long, continuous bench lines the threshold where the slabs meet, reinforcing the already blurred transition between the interior and exterior spaces of the house. Above, an oculus punctuates the upper courtyard, drawing natural light deep into the spaces below while offering a moment of pause—an aperture to the sky.

The architectural dialogue continues through a striking spiral staircase, leading upward into a tower-esque element enclosed by expansive sliding glass panels. Here, the elevation of space creates a literal, heightened sensory experience. Immersed in light and surrounded by lush greenery, the transition between these levels becomes a journey rather than a circulation path dotted with built masses.

Materiality plays a crucial role in amplifying this fluidity. The project juxtaposes raw and refined textures—like stone and concrete—forming the primary surfaces; their weight offset by the openness of glass. Brass and teakwood details lend warmth to the structural clarity. The dialogue between materials is subtle yet intentional, each plane shifting to complement the next, ensuring a seamless continuity in both form and function.

The Itaúna House is not merely an expansion of a residence; it is an expansion of thought, a testament to how minimalist architecture can enhance the way we inhabit space. Through its rather masterful play of levels, thresholds and material textures, the house acquires an additional, living dimension—one that allows it to breathe with its environment, guiding movement with light, shadow and open-air spaces. It stands as a contemporary reflection on Niemeyer’s principles, a space that invites nature in while celebrating the raw beauty and functionalism of the structure itself.

Project Details

Name: Itaúna House
Location: Rio de Janeiro, Brazil
Area: 800 sq.m.
Lead Architect: Lia Siqueira
Project Architect: Felipe Siqueira
Structural Design: Abilitá
Engineering: Stewart Engenharia
Lighting Design: Maneco Quinderé
Facade Consultant: RFR Building Design Consulting (Shanghai) Co., Ltd
Landscape Design: Isabel Duprat, Arquitetura Paisagística

(Text by Aditya Kumar, Intern at STIR)