From heatwaves to high bills: How to stay cool for less

From tackling roof radiation to smart usage of ACs, below is a bunch of actions to dealing with the scorching heat and going easy on the costs.

Delhi hit a brutal 40.5°C on March 26, making it the hottest day of 2025 and a shocking 6 degrees above normal for this time of year. While there’s been some respite due to air wind patterns, the IMD is clear that climate change is real, and the brief respite will soon be over. The met department’s predictions point to a scorching 45°C by mid-April, with the heat index potentially hitting a dangerous 50°C. Imagine becoming the world's hottest capital in 2025 and the world’s most polluted. Summer is not just coming; it's arriving with a vengeance.

In her column "Let's Get Real," Manisha Natarajan suggests a bunch of actions to deal with the scorching heat and going easy on the costs.

Let’s get real. Cribbing won’t make us deal with heatwaves or lessen our cooling bills. There are tiny to small steps that will do so. I’ve used my own 1,500 sq. ft. apartment in a four-floor building as a reference to break down the most practical solutions to making your home, whether it’s an apartment or an independent house, more heat-resistant.

Roof Rescue: Your First Line of Defence

If you live on the top floor, you know how brutal the heat can get. Good news is that the roof is where you can make one of the biggest differences. There are two solid options here: Reflective Roof Paints or Reflective Roof Tiles.

If you're looking for the most budget-friendly option, reflective roof paints are the way to go. For a 1500 sq. ft. roof, a mid-range reflective paint job costs around ₹24,000 for materials and ₹15,000 for labour. That is under ₹40,000 in total.

This simple step can slash surface temperatures by 15-20°C and lead to AC cost savings of 10-15%. Plus, your roof radiates less heat into the atmosphere, and we should prevent that as much as possible for everyone’s sake.

If you're not keen on paint and want an aesthetically better option, you can consider reflective tiles. While more expensive, costing around ₹1.5 to ₹2 lakh for a similar-sized roof, they are more durable. They can reduce heat absorption by ~30%, potentially lowering indoor temperatures by 2-5°C and cutting air conditioning costs by 15-20%. Check the tiles you pick for their Solar Reflectance Index (SRI). The higher the SRI, the more effective is the cooling. White or light colours work best.

Glass Warfare: Taming Those Sunny Windows

Big windows are great for light, not so much for heat. My east-facing bay window was a prime culprit in my home.

A surprisingly effective and budget-friendly solution I found was using desi bamboo chicks on the outside of the bay window. These bamboo chiks stop sun rays from hitting the glass. They also add a nice traditional touch. Two 3x6 ft chicks cost me around ₹10,000. I roll them up when I need a view of the expanse of the wonderful DDA park in front and bring them down to block direct sunlight, very effectively.

For homes with large glass facades exposed to direct sunlight, there are more advanced options. Multi-layer glazing, like double or triple panes, provide excellent insulation by using gas-filled gaps between the glass layers to block heat and sound (added advantage). This option is more expensive but totally worth it.

A double pane will add an extra ₹200- ₹400 per sq. ft (plus installation) and triple pane is a significant ₹800- ₹1200 per sq. ft. extra. The change from your regular glass facades to double or triple pane glass will also require some level of civil work. It’s unfortunate that even as large sliding glass doors are becoming a norm in most apartments, builders simply don’t give you double or triple-glazed panes. Unless you push. Please do.

A more budget-friendly alternative for almost all glass doors and even smaller sun facing windows, are solar control films. These adhesive films can make a reasonable difference in reducing heat gain, glare, and UV radiation. The costs for these films range from ₹60 to ₹100 per sq. ft. And you have a choice of shades as well.

Air Conditioners: Cool Smarter, Not Costlier

When it's time to replace your old AC, seriously consider investing in a 5-Star rated one. The Bureau of Energy Efficiency (BEE) in India gives star ratings to appliances like ACs to show their energy efficiency. More stars mean less energy consumption. While a 1.5-ton 3-star AC might cost around ₹38,000, the 5-star version from the same brand could be about ₹10,000 more, at ₹48,000. That extra ₹10,000 today, buys you serious energy savings, as a 5-star AC can use around 25% less energy to deliver the same amount of cooling. That 25% energy saving directly translates to lower electricity bills and based on my own usage during our long summers last year, I could recover that initial extra cost within one year.

Beyond just owning an AC, how you use it makes all the difference. The BEE recommends setting it at 24°C. I know, many of you are probably thinking, “That’s not even air conditioning!” But remember, every degree lower can hike up energy consumption by 5-10%.

Luckily, in India, most of us have ceiling fans, which help circulate the cool air, so you don’t feel the need to set the AC below 23°C. I’ve had my own battles at home. My kids used to set it to 20°C, only to then snuggle under thick blankets. Sounds familiar?

And then there are the owners of those swanky homes, who refuse to install a fan because it doesn’t look ‘posh.’ Well, we can only say, being sustainable is the most fashionable choice you can make for your own sake.

We all know the basics of effective AC cooling; keeping doors and windows tightly shut, using curtains or blinds to block out direct sunlight, and cleaning air filters every alternate month for better airflow. But let’s be honest, we tend to slip up.

Let’s not.

Every small change cuts cooling costs reduces reliance on coal-generated energy (a major greenhouse gas emitter) and shrinks our carbon footprint. It all adds up.