grat studio’s rural biaix house in barcelona reintroduces traditional catalan lime mortar

Casa Biaix reconstructs farmhouse along the Aubareda Path

GRAT Studio reconstructs Casa Biaix along the Aubareda Path in Barcelona, integrating traditional Catalan architectural elements with contemporary design. Positioned on a small hill within a pine forest and an olive grove, the structure is in close proximity to one of the city’s oldest oak trees. The design preserves the historical exterior shape of the farmhouse while introducing a new formal and material language inside. It frames views of the regenerating landscape, partially transformed by a recent wildfire. An austere materiality of lime mortar is applied throughout the project, reintroducing a material traditionally used in rural houses. The local limestone, characteristic of the interiors in Catalonia, defines the color palette of the project.

all images by Simone Marcolin

GRAT Studio utilizes traditional lime mortar and local limestone

GRAT Studio’s architectural team organizes the daytime program on the ground floor to enhance visual connections with a landscape that changes throughout the seasons. On the upper floor of Casa Biaix, the rooms are arranged along a diagonal hallway that shapes the distinctive interior geometry. That oblique form is used to optimize service spaces and accommodate an additional room for the family. The adjacent annex becomes a new living space, connected to the main house by a new spiral staircase. The rear facade opens up, making the house completely accessible and exposed to the elements.

Casa Biaix integrates traditional Catalan elements with contemporary design

lime mortar, traditionally used in rural houses, defines the materiality

a new formal and material language is introduced within the interior

a newly designed spiral staircase connects the annex to the house

the metallic white staircase subtly contrasts the interior’s rustic textures

a diagonal hallway on the upper floor organizes the interior layout

large openings establish strong visual connections with the natural surroundings

interior spaces balance tradition and modern functionality

the project’s color palette is influenced by Catalonia’s characteristic limestone

GRAT Studio emphasizes material continuity with local construction techniques

the oblique geometry optimizes service spaces and incorporates an extra room

Casa Biaix harmonizes past and present through thoughtful design choices

project info:

name: Casa Biaix
architect: GRAT Studio | @grat.works

location: Aubareda Path, Barcelona, Catalonia, Spain

lead architect: Guillem Elvira

photographer: Simone Marcolin | @simoneemarcolin

designboom has received this project from our DIY submissions feature, where we welcome our readers to submit their own work for publication. see more project submissions from our readers here.

edited by: christina vergopoulou | designboom