Facade Systems for Indian Conditions

A façade in India has to survive 45°C surface temperatures, a monsoon that drives rain horizontally, dust that coats everything within a week, and a maintenance regime that in practice may consist of nothing at all for a decade.

Most façade failures here are not material failures. They are detail failures, and they are predictable.

Glass and curtain walling

Where it works: commercial buildings where the internal environment is fully conditioned and the envelope performance has been specified properly.

Where it fails: as a default aesthetic. A high proportion of glazing on an east or west face in North India is a thermal liability that the mechanical system pays for every day of the building's life.

The specification that matters: the glass unit's solar heat gain coefficient, not just its visible tint. A great deal of Indian curtain walling uses glass selected for appearance, with the performance discovered afterwards.

The details that fail: thermal movement joints, the sealant at frame junctions, and drainage within the frame. A curtain wall is not a watertight barrier, it is a drained and pressure-equalised system, and it works only if the drainage paths are actually built as drawn. They frequently are not.

Stone

Where it works: almost everywhere in this region. Stone ages well, resists UV completely, and handles heat without dimensional drama.

The decisions: dry cladding on a stainless steel support system versus wet fixing. Dry cladding is more expensive, permits movement, allows a drained cavity and is far more repairable. Wet fixing is cheaper and more likely to fail by delamination, particularly on large formats and on the sun-facing side.

The details that fail: corrosion of fixings where a lower grade of steel was substituted, inadequate movement allowance, and open joints without a proper backing so that water reaches the substrate.

The advantage nobody prices: a stone façade at twenty years, cleaned, looks like a stone façade. Very few systems can say that.

ACP and metal composite

Where it works: signage-scale elements, soffits, fascias, and buildings where a sharp planar finish is wanted at a controlled cost.

Where it fails: as a whole-building envelope on a project without maintenance. ACP panels oil-can, visibly ripple, when the substructure is not flat or when thermal movement was not allowed for. Colour fade is real, and it is uneven, so a partially replaced panel never matches.

The safety point that must not be skipped: the core specification. Fire performance of the core material is a life-safety question and it is one where substitution during procurement has caused catastrophic failures internationally. Specify it, and verify what actually arrived on site.

Plaster and paint

Where it works: most residential building in India, and there is no shame in it. It is economical, repairable, and adaptable to any geometry.

Where it fails: at the details. Cracking at junctions between dissimilar materials, water staining below every unshaded projection, and algae on the shaded southern and western faces after two monsoons.

The details that decide it: a drip groove under every projecting element. Every one. This single detail, costing almost nothing, is the difference between a façade that streaks within one monsoon and one that does not. Then: proper movement joints, correct mesh at material junctions, and an elastomeric exterior coating rather than the cheapest option.

Terracotta and screens

Baguettes, louvres and jaalis do genuinely well here, shading, permitting air movement, and ageing gracefully because the material's colour is its own rather than applied.

The design consideration is cleaning access. A screen is a dust trap in Delhi. If it cannot be reached, it will not be cleaned, and a screen thick with dust is a different building from the one that was drawn.

The four rules

1. Drip grooves everywhere. Under every projection, without exception.
2. Design for movement. Every material moves; the difference between systems is only whether the movement was allowed for.
3. Assume the drained cavity is doing the work. Sealant is a first line, not the barrier. Anything relying on a bead of silicone for watertightness will fail within five years.
4. Design for how it will actually be maintained, which in most Indian buildings means rarely and without specialist access. Choose the system that looks acceptable when neglected, not the one that looks best when new.