Duplex on Avenida da Liberdade, Lisbon, Portugal
French-speaking interior architect Elsa Sibuet, based in Lisbon since 2019, led the complete transformation of this 110 m² duplex apartment located on the prestigious Avenida da Liberdade. The project encompassed interior architecture, decoration, furnishings, and the design of the outdoor terraces.
Location: Avenida da Liberdade, Lisbon, Portugal
Type: Residential duplex apartment
Area: 110 m²
Scope: Interior architecture, decoration, furnishings, and terrace design
Avenida da Liberdade is one of Lisbon’s most sought-after addresses. Its broad tree-lined avenues, prestigious architecture, and central location make it an exceptional residential destination.
This 110 m² duplex apartment already possessed many desirable qualities: high ceilings, two terraces overlooking the city, and generous living spaces. However, it required thoughtful intervention to fully reveal its potential.
The first step was identifying what the apartment lacked. The answer was clear: light. A solid stair railing obstructed the natural flow of light through the main entrance. This observation became the starting point for the entire renovation.
The original solid stair guardrail was replaced with a custom-designed black metal balustrade featuring rounded forms designed by Elsa Sibuet. Natural light can now move freely between the two levels, visually connecting the living spaces throughout the duplex.
The two terraces overlooking the city presented a different challenge. The main terrace received intense sunlight, causing the kitchen and dining area to overheat during the day. To address this, a pergola was constructed on the south-facing terrace, creating a balance of shade and sunlight while preserving openness.
Indirectly illuminated sheer curtains were also added, providing privacy and softness to the outdoor living spaces.
The original white walls were finished with a sand-textured brush-applied paint, introducing depth and texture without adding visual heaviness.
In the living room, the ceiling was covered with straw wallpaper highlighted by indirect lighting—a bold design choice that immediately establishes a warm and authentic atmosphere.
The living room’s main wall was completely redesigned to become the focal architectural feature of the space. It incorporates:
An ethanol fireplace
The television
A rounded recessed niche with shelving
These elements are unified by a black tiled base, which also appears as the backdrop of the staircase bookcase. This subtle design thread ties together the apartment’s architectural features.
Furniture and lighting were selected with the same attention to detail. Each piece subtly references the colors and forms used throughout the architecture without directly imitating them. The result is a sophisticated, timeless apartment where even the boldest design decisions feel natural and inevitable.
In a light-filled apartment, the central challenge is not obtaining light but distributing it effectively.
Natural and artificial light can be directed, shaped, and staged. Replacing a solid guardrail with an open balustrade or introducing a pergola that softens sunlight without enclosing the space are examples of structural interventions that dramatically alter atmosphere.
In this project, the interior architect acted as a true conductor of light, orchestrating how it moves throughout the home.
This Avenida da Liberdade duplex is a distinctly Lisbon project: rooted in one of the city’s most prestigious neighborhoods and designed to unlock the potential of an exceptional property without requiring radical transformation.
The project demonstrates Astesi Blue’s ability to deliver sophisticated residential renovations in Lisbon, supported by Elsa Sibuet’s deep knowledge of the local market and the network of craftsmen she has developed since relocating to Portugal in 2019.
Do you have an apartment in Lisbon that needs renovation or interior design?