Glass, Reframed!
Glass façades, quintessential aesthetic building envelopes globally, have been widely adopted in India as well. But when the focus is high-performance building systems that deliver energy efficiency, comfort and architectural identity, glass isn’t the only preference.
Combination solutions, involving glass and some other material, improve façade outcomes. Some combinations come at comparable prices, some at a higher price. Here is a selection of performance-oriented solutions.
Louvre-glazing-texture paint mashup
For the 20,708 sq ft office of Pioneer, Sapna Aggarwal, Founder, ANSA Architecture & Interiors, opted to use aluminium louvres, texture paint and glass selectively, based on performance rather than simply aesthetics.
“The building has a fairly large glazed surface, so our primary concern was heat gain from the significant solar radiation exposure, glare and long-term energy consumption,” she explains. “We specified a high-performance low-e/solar-control glazing for the curtainwall areas, while keeping the more solid portions of the facade in a thermally better-performing cladding system. We used the vertical solid elements, recessed glazing and architectural fins as part of the performance strategy as well as the design language. So, the architectural expression and environmental performance work together rather than competing with each other.”
The idea was to allow daylight and the visual openness of glass without turning the building into a heat trap.
If aesthetics alone had been the priority, Aggarwal says she would probably have pushed the façade much further towards a larger uninterrupted glass envelope, with a more uniform glass treatment, either through clear, highly reflective or purely decorative glass. It would have looked lighter, sleeker and more contemporary, but it would also have increased solar gain and placed a greater load on the air-conditioning system.
In terms of cost, a standard clear/architectural glass solution might typically be in the range of `450-650/sq ft, whereas a good-quality solar-control low-e double-glazed system can be approximately `900-1,400+/sq ft, depending on specification, thickness, coating, framing and performance requirements. Thus, the initial façade cost can be substantially higher. Aluminium louvres cost around `450/sq ft while the texture paint (Sirca) was `150/sq ft.
But Agarwal emphasises that the differential shouldn’t be seen only as an additional façade cost. “Calculating the lifecycle cost – reduced cooling load, improved occupant comfort, lower glare and potentially lower energy consumption over the life of the building – is far more important,” she reasons.
“The best facade is not the one that looks the most expensive,” says Aggarwal. “It is the one where the material is doing more than one job: creating the architecture, controlling the climate and contributing to the building’s efficiency.”
External louvres improve performance
The 1,80,000 sq ft Fybros office-cum-warehouse in Noida combines a curtainwall with a full filtering external louvered screen.
With the west-facing front façade opening into the reception presenting direct exposure to the harshest part of the day, and a low-angle evening sun difficult to shade with a simple overhang, the façade had to perform before it could impress.
“A fully transparent glass façade here would have looked striking, but it would have compromised the very space it was meant to enhance,” points out Vinod Singhi, Founder & Principal Architect, BASICS Architects.
In his solution, “the glazed curtain wall using triple-glazed windows preserves the visual connection to the park in front, while the external louvres sit in front of it as a filtering layer, cutting direct solar heat gain and glare while breaking up the low sun angle before it reaches the glass.” Paired with heat-reflective paint on adjoining surfaces, the curtainwall keeps indoor temperatures 4-5°C cooler than outside and reduces the air-conditioning load by 20-25 per cent.
Shifting patterns of light and shadow through the reception across the day, a secondary benefit cast by the louvres, have become a defining architectural feature that emerged directly from a performance decision.
The base structural glazing for the curtain wall costs approximately `2,200/sq ft while the external louvres added on top add roughly `2,000/sq ft extra. A purely glazed structural façade without the louvered shading layer would have come in closer to the `2,200/sq ft mark, a straightforward saving of nearly 50 per cent upfront. But that saving would have been offset through the building’s life by the extra cooling load.
Contemporary jaali-inspired perforation shaded glazing
“We designed the façade of the Lohia Worldspace Experience Centre in New Moradabad to deliver both architectural character and environmental performance,” says Kulveer Bhati, Architect, TOD Design Innovations. “While the building’s sculptural, parametric identity creates a strong first impression, we selected every component of the envelope with efficiency in mind.”
He adopted a layered system comprising CNC-cut aluminium and composite panels with jaali-inspired perforations, complemented by high-performance floor-to-ceiling glazing. The perforated outer skin acts as a passive shading element, filtering harsh sunlight, reducing solar heat gain and allowing diffused natural daylight into the interiors. Strategically positioning the glazing maintains visual openness and transparency while supporting thermal comfort.
The design draws inspiration from Moradabad’s brass craftsmanship, reinterpreted through a contemporary parametric jaali.
“If visual expression alone had driven the design, we would have opted for a predominantly glazed façade to create a more transparent and minimalist appearance,” continues Bhati.
However, in North India’s climatic conditions, such an approach would have increased solar heat gain, glare and dependence on air-conditioning while also resulting in higher maintenance requirements.
The customised parametric façade required precision fabrication and cost Rs.475/sq ft as against a similar cost for a conventional aluminium cladding system and Rs.743/sq ft for a premium fully glazed curtainwall façade.
Calibrated jaali-design blend
At the Central Court Residence, a multi-generational four-storey home in Alipore, Kolkata, a façade composed of a carefully calibrated combination of terracotta jaalis, deep overhangs, and selectively placed glazing regulates solar exposure, reduces glare, encourages cross ventilation, and creates comfortable interiors throughout the year.
This decision was driven by three key considerations,
according to Kaushik Mukherjee, Principal Architect, Kaushik Mukherjee Architects: “Thermal performance, energy efficiency and long-term durability.”
Also, terracotta carries cultural significance for the family, drawing inspiration from the temples of Bishnupur, while marble references the stone havelis of Fatehpur.
“If we had prioritised visual impact as the key characteristic of the facade, it would have featured larger glazed surfaces to create uninterrupted views and a stronger sense of transparency,” explains Mukherjee.
The selected approach instead balances openness with climate responsiveness, privacy, and everyday comfort, at a similar cost – approximately `15,000/sq ft – to extensive high-performance double glazing.
Curtail [AM1.1] glazing for a high-performing envelope
The owner of The Arch Essence, a residence in Jaipur, wanted a home that felt open, naturally lit and visually contemporary. However, the city’s intense solar exposure demanded a façade that could moderate heat gain without compromising spatial quality, explains Rajkumar Kumawat, Founder & Principal Architect, Rajkumar Architects.
“So, instead of pursuing transparency through extensive glazing, we focused on passive design strategies that work with the climate rather than against it. While visually striking, a glass-intensive facade would have increased heat ingress, dependency on mechanical cooling and long-term operational costs.
Using high-performance glazing only where necessary limited the overall cost impact to approximately `250/sq ft of covered area, compared with approximately `900/sq ft of covered area for a glass-intensive façade.
The façade was articulated through layered balconies, recessed openings and carefully proportioned projections that cast shadows across the building throughout the day, making the envelope a climatic device rather than merely an external skin. Natural stone cladding lent the façade durability, thermal stability and minimised maintenance over its lifecycle.
The discussion around façade design often centres on aesthetics but performance deserves equal attention, says Kumawat. “A well-designed façade should reduce energy demand, improve thermal comfort, require minimal upkeep and continue performing long after the project is completed. When these fundamentals are embedded into the design process, aesthetics naturally follow.”