Let me start with something very basic: air has to be able to enter and leave your home sensibly. Sounds obvious, but I can’t tell you how many flats I have visited where the main bedroom has one sad little window opening into a shaft, and that’s it.

On the other hand, when a room has openings on two sides, especially facing different directions, something almost magical happens on humid evenings. Even a light outside breeze turns into noticeable movement indoors.

In practice, what has worked well on my projects is:

• Making sure living rooms and bedrooms have windows or ventilators on opposite sides, not just one.
• Aligning internal doors so you can open them and get a clear path for air.
• Placing at least one outlet window or ventilator a little higher than the inlet, so warm air doesn’t just sit under the ceiling.

We once reworked an old house in Tripunithura near Kochi. No money for major air‑conditioning systems, but there was a serious damp, stale smell in most rooms. We opened a bricked‑up window, knocked out the top part of a partition and replaced it with a wooden jaali, and cut a small ventilator high on the opposite wall. Cost was modest. The owner told me after the next monsoon, “It’s the same house, but it doesn’t feel like the same house.”

That’s cross‑ventilation. It’s not glamorous, but it’s one of the most honest ways to fight humidity.

Most Indian houses are built like closed shoe boxes with a flat RCC lid. Inside, hot air collects near the roof and has no easy way to escape.

If your building has more than one level, or even just a higher central ceiling somewhere, you can make that work in your favour.

A few things I’ve used repeatedly:

• Using the stairwell as a kind of chimney and giving it a ventilated skylight or louvres on top.
• Fixing simple roof ventilators over circulation areas or service zones.
• Adding small high‑level openings, even if they are just narrow operable panes.

This is especially useful on days when there’s almost no wind outside. In such weather, cross‑ventilation alone isn’t enough. The height difference between inlet and outlet starts doing some of the work.

In our climate, the sun is not a gentle visitor. It is a laser. Once it hits bare glass or a dark wall for a few hours, the heat lingers long after sunset.

People often show me fancy glass samples with all sorts of technical data. My reaction is usually the same: “First, let’s shade the window properly. Then we’ll discuss glass.”

What I’ve found works consistently well:

• Chajjas and overhangs that actually have depth, not just cosmetic bands.
• Different strategies for different sides: south and north can often be handled with horizontal shading; east and west need vertical fins, screens, louvers or dense planting.
• Balconies as functional buffers, not just decorative ledges.
• Creepers and trees where possible.

On one small bungalow near Panaji, we had a west‑facing living room that the client absolutely refused to shift. The compromise was a deep verandah with a tiled roof and creepers on the side. You still get the sunset, but not the oven.

If you live on the top floor in a city like Chennai, you don’t need me to explain what an unprotected terrace does to the rooms below.

When you walk barefoot on such a terrace in May, the slab almost burns. That same heat travels down into your ceiling and stays there well into the night.

Some extremely simple things have helped tenants and owners over the years:

• Painting the roof surface a light colour instead of leaving dusty grey concrete.
• Using proper cool roof coatings or reflective tiles where budget allows.
• Adding insulation above the topmost ceiling, especially when a false ceiling is being added.
• Creating a ventilated double roof in independent houses.
• On tight budgets, placing modular planters or trays filled with soil or broken tiles on part of the terrace.

I’ve seen people spend more money increasing AC tonnage than what a good roof treatment would have cost them in the first place.

One thing that often gets ignored in apartment projects is the microclimate at ground level. You can’t pave everything with concrete and expect evenings to feel pleasant.

A few patterns I encourage whenever I get the chance:

• Trees, especially on the east and west sides of a plot.
• Limiting continuous hard paving and breaking it up with planting beds or permeable pavers.
• Designing verandahs, sit‑outs and shared semi‑open spaces that don’t bake in reflected heat.

At a housing project outside Mangaluru, we didn’t have the budget to alter the built masses much, but we did rework the internal roads, tree positions and walkway shading. Residents later reported that the campus “felt cooler” in the evenings, though no one measured exact temperatures. Sometimes perception is as important as numbers.

A lot of marketing these days is around “advanced” materials, but our old, simple materials still work very well if used intelligently.

From humid‑climate projects, a few things have stood out for me:

• Traditional brick or laterite walls, properly shaded, give steadier indoor temperatures.
• Light coloured external finishes reflect a lot of unwanted radiation.
• Glass should be used with awareness; where budget is tight, shading plus normal glass often beats exposed premium glass.
• Stone, vitrified tile or polished cement floors generally feel cooler underfoot than synthetic wood in a humid city.

I usually tell clients: don’t get too carried away by the “green” label on a single product. Think of how that wall, that window, that roof behaves as a whole system over the course of a year.

Fans Are Not Old‑Fashioned

We have started to treat the ceiling fan as a poor cousin of the air‑conditioner. In coastal cities, it’s actually the hero.

Cooling your body is not just about reducing the air temperature, especially when the air is moist. Moving air across the skin makes a huge difference to comfort, even if the thermometer hasn’t dropped much.

The arrangement that repeatedly works is:

• Rooms designed for cross‑ventilation.
• Well‑placed ceiling fans.
• AC used for certain hours or certain rooms, not as the only line of defense.

In several homes I’ve designed in Kochi and Chennai, owners eventually discovered they could run the AC for a shorter time at night and then switch back to fans, instead of leaving the AC on till morning. The building itself and the air movement were doing more of the job.

Imagine a standard 2BHK flat in Kochi or Navi Mumbai, say around the 4th floor, slab roof above, with the long sides facing east and west.

You may not be able to move walls or change structure, but you can still:

• Add decent‑depth chajjas or external shading to the more exposed windows.
• Lighten the exterior paint colour, if your housing society allows it.
• Keep windows on opposite sides open whenever weather permits and keep internal doors open in the daytime.
• Put proper ceiling fans in each room instead of only relying on stand fans or AC.
• If you are on the top floor, request or negotiate a simple cool roof finish or partial planters above your flat.
• Use balcony plants and a simple trellis to cut harsh sun while still allowing breeze.

None of this will turn your flat into a hill station. But it can easily trim a few degrees off the feel of the space and reduce the number of hours you feel forced to use the AC.

When I was a young architect in the late nineties, my seniors rarely used the term “sustainable architecture”. They simply talked about “correct orientation”, “good ventilation”, “proper shading”, and “sense of place”. The planet‑saving terminology came later.

The basics, however, remain the same.

In a humid Indian city, a good house is one that can breathe, that knows how to protect itself from the harshest sun, and that doesn’t collapse into discomfort the moment the AC is switched off.

If you are planning to build or renovate near the coast, one question is worth asking very early:

“If all the machines went off for a day in May, would this house still be liveable?”

If your honest answer is “yes, at least to a degree”, then you are probably designing in the right direction – for your comfort, your electricity bill, and the city’s climate, all at once.