'When you have 360 degrees, why stick to one,' is a favourite quote amongst most young architects. However, this obsession with curves didn’t start from Zaha Hadid and her fluidic structures and though she did explore extended possibilities of parametric architecture in curved structures, experimentations with fluidity go way back. From the theatres of Rome and the Catalan Modernism of Antonio Gaudi to the buildings of Erich Mendelsohn and Frank Gehry, to name a few. Over the course of time, this interest in curves has evolved into new spectrums of materiality, typology, and design styles. With more advanced technologies and new materials, curved forms aren’t as challenging as they used to be and therefore can be seen in a wide range of projects.

Adding to this narrative of curves in architecture, Indian architects Nitin Barchha of Studio Humus and Pooja Bihani of Spaces and Design shaped the interiors of a residence in India. Situated in Forum Atmosphere, a luxury residential superstructure in Kolkata, Cavernous is a 480 sqm apartment for a family of four. Between the ebb and flow of curves, the organic design of the residence was envisioned to resonate with the client’s need for something unconventional that shows the possibility of materials like cement and TMT bars. However, as the design process expanded, organic form transcended the potential of materiality, creating spaces that seamlessly transition between one another.

Eponymous to its name, Cavernous shapes as a cavern—one that lies storeys above the land—where voids and openings appear to be flawlessly chiselled out of a solid whole. Talking about the design, Barchha said, "We are still evolving from our predecessors who lived in caves for millions of years and associated the curvilinear forms with the safety of the caves that they lived in. Hence when one enters a curvilinear space the subconscious immediately associates it with safety and allows one to be; further promoting deep sleep while putting the cerebral cortex to rest from its perpetual state of alertness that is part of our daily lives today.”

Bringing the organic forms of caves into the contemporary world, the interior design of Cavernous follows sinuous curves which give shape to horizontal extensions and bulbous conch-like additions, which along the spatial journey of the house can be seen transitioning into functional areas and storage spaces. From the cylindrical foyer leading to the double-height large crescent shape lobby, Cavernous embarks the users in a trail that is both comforting and dramatic. The fluid forms and sculptural helical staircase of the lobby space act as abstract additions to the curvaceous exaggerations awaiting in other functional areas. Maintaining the sense of a cave, the wall and ceiling do not exist as separate elements, but rather flow to form one entity, resembling a barrel wall that is extended to the floor slab.

In the lobby space adorning double-height openings which bring in ample sunlight, a mix of different design styles can be witnessed. The screens and window shutters lean more towards contemporary design with linear lines and a wooden palette, which helps balance the sudden change from the modern architecture of the residential superstructure to the apartment's organic architectural character. On either side of the lobby are the L-shaped living room, dining room, kitchen and master suite.

"I think the highlight for me is this L-shaped double-height space. It is an absolute fascination and a wonderland. As soon as one enters, the staircase anchors the mind, but when you move beyond the staircase, that is where the larger-than-life picture of the project comes out. And the best part is when you turn around at the end of the L-shaped height of the living room, you see the shell form of two toilets—like a conch in contradiction to each other,” shares Bihani. While the living room presents itself in an avant-garde grandeur, the dining room is amoebic in nature—free-flowing and built into the wall.

The sculptural helical form of the staircase design leads to the upper floor, hosting four bedrooms. Due to the fluidity in the way that the wall, floor, and ceiling are connected, each room doesn’t adopt a separate aesthetic but appears to be a hidden enclosure inside a cave structure. Helping this continuity is the careful selection of the material palette. With the use of stucco-finished concrete walls, composite stone flooring, mosaic tiles, ferrocement, microcrete and composite stone, the architects try to create a built environment that is, simultaneously, subtle and dynamic. Talking about this approach, they state, "The mood of the entire space is very monotone, hence, these five-six elements are everywhere in the house. That is why the spaces look seamless and so expansive, following a singular, cohesive narrative.”

Even the furniture design follows similar characteristics and material palette in most places. At places, built-in furniture in ferrocement and concrete adds to the space and other times bespoke furniture by Craft Beton enhances the space. As the interior design of Cavernous has a pastel colour palette, the architects employed sculptural lighting to add an interesting contrast. All the light installations were also crafted by Craft Beton, including the wall murals customised for the project.

"Creating something as unique as Cavernous is like taking a shot in the dark on the first try. Challenges were posed almost every hour in the execution of the project in terms of the form derivation and accuracy of the geometry. The medium was very new to them, all along the way it was a challenge until they saw a form taking shape," shares Bihani.

She then adds, "The spaces were compartmentalised because of the way the structure was and also because the building is tall we really wanted the interiors to have a lightweight feel. When we did wall-to-ceiling forms, they were connected on all sides so the load was distributed evenly all over. Our main challenge was how to connect the disconnected spaces like the compartmentalised lower and upper levels of different heights and intersection of the L-shape double height ceiling.”

“We spent many hours on the physical implementation of the cross dome on site. Another challenge was to make the space look seamless with the forms, given the restrictions of the structure. Material integration at angles and curves to a seamless form on site was indeed difficult. Double height passage integration into single height bedrooms also required thought and innovation.”