A latticed roof rains dappled light into House Under Shadows by ZED Lab

Built for the families of two brothers in the city of Karnal in Haryana, India, House Under Shadows by Zero Energy Design Lab (ZED Lab) combines two residential units into a stately abode settled underneath a latticed roof inspired by the tessellated patterns seen in Voronoi diagrams. The dappled shadows that the roof casts during the day evoke the image of evergreen canopies in tropical rainforests. The residential architecture by the Delhi-based firm, headed by architect Sachin Rastogi, marries elements of passive vernacular architecture and parametric design, funnelled through the lens of sustainability. The idea was to create a structure that responds to its context, both in its functional efficiency and spatial experience.

Inspired by the architecture of Noor Mahal - a palatial hotel in proximity to the site - ZED Lab’s design lays emphasis on horizontality and bilateral symmetry, with a free-flowing geometric layout. The spatial organisation of both units also draws from chowks(courts) found in Indian havelis (traditional manor houses) to combat the temperate climate of North India and its effects on the south-facing residence, with a net-zero energy design approach. A grand entryway marks the point of ingress to the structure, flanked by the external walls of two mirrored residential units dry clad in Gwalior mint stone. The units serve as separate yet connected dwellings for the two siblings' families, united under the common pergola roof.

Spaces within both the units are laid about a double-height court with a rectangular pool at its centre. This water feature also takes up the function of a heat sink. While creating visual links between floors, the court at the heart of the residential design secures ample natural light while facilitating cross-ventilation throughout other spaces. Large stone-clad walls enclose the zone, some adorned with vertical greening, allowing them to benefit from the presence of the water body in their vicinity through evapotranspiration.

The master bedroom and kids’ room on the ground floor have glazed openings that face the north-western section of the site to mitigate glare and heat gain while offering serene views of the landscaped garden outside. Alternatively, the main living areas are screened against harsh incoming sunlight from the south-west by the courtyard. These spaces include a combined lounge and dining area, a kitchen, bar, powder room, and a formal living room. Panelled ceilings finished in natural Indian wood maintain continuity throughout the various zones. Lattice screens serving as partitions in the style of traditional jaalis echo the motifs of the roof canopy while subtly segregating zones in the living areas and washrooms. A staircase opposite the central court in each unit connects these spaces to the upper floor.

On the first floor, a bedroom, a lounge, powder room, pantry, store, and a multipurpose hall constitute the main program areas. With a hexagonal footprint, the design of the multipurpose hall is inspired by traditional chhatris, which are elevated, dome-shaped pavilions prominently featured in medieval Indian architecture. The rest of the upper level functions as a partially-covered terrace for residents to take in the surrounding scenery of the neighbourhood as well as the landscaped gardens below.

As the design’s crowning feature, the expansive roof canopy with its intricately crafted perforations enables drops of sunlight to rain into the space, creating an ephemeral play of shadows that varies both diurnally and in accordance with seasonal changes. Devised with the aid of parametric digital modelling, the canopy emulates Voronoi diagrams, which are often used in the fields of ecology and hydrology to study forest canopies and rainfall patterns, respectively. The lattice was fabricated using a Fibre Reinforced Polymer (FRP) and mounted onto a mild steel frame linked to the structural grid. Extending along the length and breadth of the house while cantilevering over its sides, the structure is held up by slender steel columns.

According to ZED Lab, the inclusion of the double roof system reduces both direct and diffused solar radiation by nearly half their expected value, which also greatly diminishes cooling loads within the residence by over 20 per cent. Besides this, the use of locally sourced materials with low embodied energies and carbon footprints also contribute to the home’s eco-friendly design.

Floor-to-ceiling windows set within aluminium glazing provide sufficient natural light while the home’s doors were assembled on site using pre-polished Indian veneer. Neutral tones, earthy textures, and colours alongside splashes of green and leathered stone finishes define the atmosphere of the interior design.

House Under Shadows cohesively reinterprets the notion of 'Modern Indian Living' in a sustainable vein, combining tradition and technology into a design scheme executed with impeccable finesse.

Project Details

Name: House Under Shadows
Location: Karnal, Haryana, India
Built-Up Area: 1672 sq.m
Client: Sahil Gandhi 
Principal Architect: Zero Energy Design Lab (ZED Lab)
Design Team: Lead: Sachin and Payal Rastogi
Contractor: Supreme 
Plumbing: One Design Consultants
Completion Year: 2021