Keeping Your Home Warm in a Gujarat Winter: Myths vs Facts

Ten to twelve degrees. That is roughly where January nights settle in Ahmedabad and Rajkot in a normal winter, with Surat a few degrees warmer and parts of Kutch and north Gujarat dropping into single digits during cold spells. By the standards of a hill station it is mild. But Gujarat homes are built for heat — marble and vitrified floors, large sliding windows, high ceilings, ventilators that never close — and a house designed to shed heat for eight months does exactly the same thing for the other four. The result is a living room that feels colder than the street at 7 a.m., and a family debating whether to buy a second heater.

Much of what people do about it is based on half-truths: that the floor is the problem, that every window should stay shut, that a heater is the only answer, or that insulation is a summer topic. This article takes eight of the most common beliefs, checks each against the physics of the building and the numbers, and turns each into something practical to do. The fixes are mostly cheap; the few that cost money are the ones that also cut summer bills.

Myth: Gujarat winters are too short and mild to design for

Fact: the cold period is short, but the discomfort is real because the house cannot hold heat. Indoor comfort depends not only on air temperature but on the temperature of the surfaces around a person — floors, walls, glass and the ceiling. A top-floor bedroom under a bare RCC slab, a wall of single glass and an uncarpeted stone floor can all sit several degrees below the air, and the body loses heat to them by radiation. That is why a room at 18 °C can feel colder than the 18 °C terrace in the afternoon sun. The good news is that the same measures that keep a home cool in May — a shaded, insulated roof, well-sealed windows and sensible glass — keep it warmer in January. Designing for winter in Gujarat is mostly designing well for summer, then adding a few habits.

Myth: Marble and tile floors make the room cold, so carpet the whole house

Fact: a stone floor is not colder than the air above it; it feels colder because it draws heat from bare feet faster than wood or fabric does. Wall-to-wall carpet fixes the feel but brings dust, mites and cleaning trouble that most Indian households do not want for twelve months. The better answer is targeted: a dense rug under the sofa and the coffee table, runners beside beds, and slippers. Stone floors also have an advantage in winter. Their thermal mass stores heat from any sunlight that reaches them in the day and gives it back slowly after sunset. A sunlit patch of floor near a south window can be the warmest surface in the house by evening, so it should be left bare, not hidden under a rug.

Myth: Keep every window shut all day to keep the warmth in

Fact: shutting out the winter sun throws away free heat. Gujarat lies at roughly 21–24° north, so at noon around the winter solstice the sun stands only about 43–46° above the southern horizon, low enough to shine deep into rooms through south-facing glass. East windows catch the morning sun, west windows the afternoon. The rule is to open curtains on sunny glass during the day, close them at sunset, and still air the house for 10–15 minutes around midday, when outside air is warmest. Some ventilation is essential in winter too, to clear moisture from cooking and bathing and stale air from closed bedrooms, and especially where any fuel is burned.

Myth: A room heater running all night is the only real fix

Fact: a heater is a supplement, and running one all night is expensive and, used badly, dangerous. A 2,000 W fan or quartz heater on for eight hours uses 16 units; at an illustrative tariff of ₹6–9 per unit that is ₹96–144 a night, or roughly ₹2,900–4,300 for a month. An oil-filled radiator of 1,500 W with its thermostat cycling about half the time uses around 6 units a night, about ₹36–54. Better still, warm the room for an hour before bed, close the door and curtains, and switch off or let a timer do it. Safety comes first: plug heaters directly into a 16 A socket on a properly rated circuit, never into an extension board or a 6 A socket, keep them a metre from curtains and bedding, and never use a charcoal angithi, a gas heater or a kerosene stove in a closed bedroom. Burning fuel in a sealed room can produce carbon monoxide, which has no smell and can kill in sleep.

Myth: Roof insulation is only a summer topic

Fact: the bare RCC roof that bakes a top-floor flat in May is also the surface that drains its warmth on a clear January night. An uninsulated slab has a U-value of roughly 2.5–3.5 W/m²·K; 50 mm of XPS over the slab brings it down to about 0.5, cutting heat flow through the roof by around 80 per cent in both directions. A full over-deck system with screed and tiles costs about ₹150–350 per sq ft, and under-deck insulation above a false ceiling about ₹60–150 per sq ft (indicative October 2026, as in this site's insulation guide). Because the payback comes from both seasons, top-floor homes are where insulation pays fastest.

Myth: Curtains are decoration, and glass does not lose much heat

Fact: glass is the weakest part of the envelope. Single glazing has a U-value of roughly 5.7 W/m²·K, many times that of a brick or AAC wall; a typical double-glazed unit with an air gap brings it to roughly 2.7–3.0. In a Gujarat home with large sliding windows, the glass can lose more heat at night than all the walls together. Replacing glazing is a renovation decision, but curtains are an immediate fix: heavy, lined curtains that run from ceiling to floor and past the sides of the window, closed at sunset, trap a layer of still air against the glass and noticeably reduce the cold radiating from it. A pelmet or ceiling track stops warm air leaking over the top.

Myth: Small gaps under doors and around windows do not matter

Fact: in many homes, draughts cause more discomfort than any other single factor, because moving cold air at ankle and shoulder height cools people faster than still air at the same temperature. Common gaps are the 10–20 mm under bedroom doors, worn rubber in aluminium sliding tracks, unused kitchen and bathroom ventilators, and openings around AC pipes. Brush or rubber door-bottom seals, self-adhesive weather strips on shutters and well-fitting sliding-window brushes cost little — typically a few hundred rupees a door or window in material — and can be fitted in an afternoon. Ventilators in kitchens and bathrooms should stay open or fitted with exhaust fans, because winter condensation and fumes still need to escape; seal the gaps nobody planned, not the ones that do a job.

Myth: The air-conditioner is useless in winter

Fact: many inverter split ACs sold in India are reverse-cycle, or "hot and cold", models — heat pumps that move heat from the outdoor air into the room. In Gujarat's mild winters, where outdoor temperatures rarely approach freezing, a heat pump delivers several units of heat for each unit of electricity, far more efficient than any resistive heater that turns one unit of electricity into one unit of heat. Families buying a new AC for a bedroom or living room should check whether a heating mode is offered; for an existing cooling-only unit, the answer is a heater on a timer. Either way, the room should be closed, curtained and draught-sealed first, so the equipment is heating the room rather than the street.

Myths and facts at a glance

Frequently asked questions

Is it safe to sleep with a room heater on?

An electric oil-filled radiator with a thermostat, plugged directly into a suitable socket and kept clear of bedding and curtains, is the safest type for a bedroom, but it is better to pre-warm the room and switch off or use a timer. Fuel-burning heaters, angithis and stoves should never be used in a closed room because of the carbon monoxide risk.

Which room heater is best for Gujarat winters?

For bedrooms, an oil-filled radiator with a thermostat gives steady, quiet heat; for short bursts in a bathroom or before bed, a fan heater works quickly. Where a new AC is being bought anyway, a reverse-cycle inverter model can heat far more efficiently than either. Check the wattage against the socket and circuit before buying.