raw concrete and steel anchor stripped-back 1960’s apartment in zagreb

simple architecture approaches the renovation through subtraction rather than addition, stripping the apartment back to its raw state.

Simple edited by christina vergopoulou November 8, 2026 3 min

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SIMPLE ARCHITECTURE STRIPS 1960S APARTMENT TO RAW CONCRETE SHELL

Sited in the western district of New Zagreb near the Sava River, Raw Apartment by Simple Architecture is an interior renovation executed within a 1960s experimental residential block. The original building was constructed using the JU61 prefabricated system, a modular assembly of load-bearing reinforced concrete walls that double as internal partitions, wrapped in an exterior envelope of corrugated steel sheet panels. The renovation adopts a subtractive methodology, stripping away accumulated surface finishes from the walls, floors, and ceilings to lay bare the prefabricated concrete substrate.

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all images ©Simple Architecture

Exposed structural steel columns support concrete envelope

The floor plan, reconfigured by Simple Architecture Studio, comprises a combined living and dining area, kitchen, bathroom, and single bedroom. To expand the primary living zone, two compartmentalized rooms were merged into a single open-plan volume. Because all interior walls in the JU61 system are structurally load-bearing, the removal of the dividing concrete wall required the insertion of structural steel columns and transfer beams, which are left exposed as visual records of the structural intervention.

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exposed concrete defines the living and dining space, with steel and aluminium elements continuing the apartment’s industrial language

GLASS AND TEXTILE DRAPERY OFFSET METALLIC JOINERY AND JU61 PANELS

The interior palette reflects the building’s Brutalist lineage and industrial cladding. Built-in and freestanding furniture pieces are fabricated primarily from steel and aluminum, while full-height mirrors and glass panels replace conventional partition doors to direct light through the floor plate. In the bathroom, replacing a solid concrete partition with translucent glass channels daylight from the bedroom into the previously dark core, concurrently backlighting an open wardrobe system. Floor-to-ceiling textile drapery acts as an operable partition system, offering solar modulation and adjustable spatial division against the exposed concrete shell.

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the orange poster is a memento of the 1976/1977 concert season, when major classical musical stars came to Zagreb

zagreb-raw-apartment-simple-architecture-interior-renovation-designboom-1800-3 — the former two-room layout was opened into a single, generous living space, supported by exposed steel beams and columns

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mirrored surfaces replace conventional doors, reflecting the raw concrete structure and extending the perception of space

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curtains create flexible divisions between spaces, allowing the apartment to open up or close down as needed

zagreb-raw-apartment-simple-architecture-interior-renovation-designboom-1800-1 — the raw, unpainted concrete surfaces retain original construction markings and cast textures

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existing concrete surfaces remain exposed and raw, revealing the original structure and layers of the building

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reading area with a lounge chair, echoing the building’s original modernist language

zagreb-raw-apartment-simple-architecture-interior-renovation-designboom-1800-2 — rough masonry and rough concrete cutouts around doorways document the physical layers of the building envelope

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the bedroom retains the apartment’s raw materiality, with exposed concrete balanced by soft textile elements

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an open wardrobe system is set against translucent glass, which brings natural light deeper into the apartment

the open layout prioritizes cross-ventilation and unhindered light distribution across the living spaces textural contrasts balance cold steel and concrete finishes with woven textile partitions minimalist kitchen joinery incorporates stainless steel countertops and industrial-grade aluminum panels a compact kitchen in steel and aluminum, continuing the apartment’s raw material palette the illuminated glass partition creates depth while visually extending the compact bathroom translucent glass replaces the solid wall between the bathroom and bedroom, bringing natural light into the otherwise dark space floor plan

the open layout prioritizes cross-ventilation and unhindered light distribution across the living spaces textural contrasts balance cold steel and concrete finishes with woven textile partitions minimalist kitchen joinery incorporates stainless steel countertops and industrial-grade aluminum panels a compact kitchen in steel and aluminum, continuing the apartment’s raw material palette the illuminated glass partition creates depth while visually extending the compact bathroom translucent glass replaces the solid wall between the bathroom and bedroom, bringing natural light into the otherwise dark space floor plan

project info:

name: Raw Apartment
architect: Simple Architecture | @smplarchitecture

location: Zagreb, Croatia

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