Local conditions
What the coast does to a window
Visakhapatnam sits on the Bay of Bengal, and within two to three kilometres of the coast the air carries enough salt to attack metal directly. Aluminium frames in that band typically show pitting and rust within three to five years. uPVC has no metal exposed to the air, so corrosion is not a failure mode here.
The same coastline is cyclone-prone, which changes what a window has to be specified for. Frame reinforcement and glass specification matter more here than they do inland, and upper floors need heavier configurations than ground floors. Visakhapatnam also takes over 1,000mm of rain a year, much of it driven sideways by wind — EPDM gasket seals and multi-point locking are what keep that water out, and they are exactly what fails on older wooden and aluminium frames.
Year-round humidity is the fourth condition. It warps and swells wooden frames until they bind in the opening; uPVC is dimensionally stable and does not absorb moisture. Sea-facing apartments in Rushikonda, Yendada and Bheemunipatnam meet all four at once — salt, wind, rain and humidity — which is why replacement demand is highest in those developments. Replacing old aluminium windows? Here's how to tell if yours are past saving.
