The roof is also a room

A dwelling room, in the Indian census, is a room with walls, a doorway and a roof, at least two metres long, one and a half metres wide and two metres high. The definition is careful and it has one consequence nobody intended: the roof itself is not a room. It has no walls and no doorway. It is the surface that makes other spaces count as rooms, and it does not count as one.

Which is a problem, because for three or four months a year it is the part of the house that gets used. Not used occasionally, or as a view. Used for sleeping, for drying, for storing, for arguing, and for the slow construction of the floor that will one day be built on it.

What the arithmetic leaves out

Thirty-seven per cent of Indian households live in one dwelling room; another thirty-two per cent have two; four per cent have no exclusive room at all, because the room is also the shop. Put differently, about seven households in ten have two rooms or fewer, and a household is not one person. A one-room house with five people in it has no internal space that can be given to anything without taking it from something else.

The roof is the only additional space that costs nothing. It cannot be bought, because it is already there; it cannot be rented, because it has no address; and it cannot be counted, which is precisely why it is available. In a country where the housing shortage is measured in millions of units, the largest uncounted room in the country is the one on top.

Why it is cool up there

The physics is not mysterious and it explains the habit exactly. A concrete slab absorbs heat all day and gives it back slowly. Outdoors, that heat leaves the surface at night by radiation to a sky that is, in effect, a very cold object: an unshaded roof loses heat upward faster than the air around it can replace it. So the roof at two in the morning is the coolest place in the building, while the room underneath it — with a slab above, walls around, and one small window — is still holding the afternoon.

This is why the roof is comfortable in April and why the room below it is unbearable in June: the slab that was an advantage at night becomes a lid in the day. And it is why the cheapest housing intervention in the country turned out to be a coat of white paint. Reflecting sunlight off the slab means less heat is stored, so less is released at ten at night, which is when the household is trying to sleep.

The roof becomes public policy

In May 2010 a heat wave in Ahmedabad killed more than a thousand people, and the city's response, three years later, was the first heat action plan in South Asia. It had the usual apparatus — colour-coded warnings, cool rooms in hospitals, water distribution, adjusted working hours — and one measure that was almost embarrassingly simple. Teams painted the roofs of low-income tin-roof houses with reflective white coating, and measured what happened indoors. The best results were around five degrees cooler.

Five degrees is not air conditioning. It is the difference between a room you cannot sleep in and a room you can, and it costs a fraction of a split unit plus the electricity to run it. The model was copied, first across Gujarat and then, under national heat guidance, across a large number of cities. Which is the interesting part: to help the roof, the state had to stop treating it as private space and start treating it as a surface — a thing with an albedo, a measurable reflectance, a place where public money can be spent.

That reclassification is not neutral. A roof that is a room belongs to a household; a roof that is a surface belongs to a programme. The same logic explains the other things that have arrived on Indian roofs in the last twenty years: the water tank, which made the roof structural; the mobile tower, which made it rentable; the hoarding, which made it a billboard; and the solar panel, which made it a power station with a meter. Every one of these pays the household or the building, and every one of them occupies the space where the family used to sleep.

The second floor is a savings account

There is another roof logic, and it is financial. In most Indian cities a house is not bought finished; it is built in stages as money arrives. The roof is where that is visible: steel bars left sticking out of the slab, a stairhead built to full height with a door that opens onto nothing, a parapet that is already the wall of a future room. The roof is a savings account that pays interest in square feet, and the family that sleeps on it is sleeping on its own next asset.

This is also why roof rights are a separate thing in Indian property practice. A barsati — the small room on the terrace — is rented separately from the flat below, sometimes to a different household, sometimes with its own entrance and its own water connection. The roof can be sold as a right even when it cannot be sold as land, which is an old arrangement and a very practical one: the poorest tenant in a building often lives on top of it.

What the lift removed

The roof as a room depends on a stair. Not a lift, not a lobby, not a fire-escaped core with a locked door at the top — a stair you can walk up in the dark carrying a bedding roll. When housing goes vertical in the way Indian cities now build, that stair usually becomes a service stair, and the roof becomes a machine room with a locked hatch.

So the practice does not disappear, it relocates. In a gated tower the equivalent of the terrace is the podium, the lawn or the clubhouse, and all three are private property with opening hours and a rule against cooking. The family that used to sleep on its own roof now sits in a park it does not own, at a time someone else decides. The room did not get better. It got administrated.

The cheapest room

The roof is the clearest case in the country of a space that exists, is used daily, and appears in no table. It is not a loophole; it is what the definition of a room leaves out. And the way it has been handled tells you how the state deals with things it cannot count: it does not measure the room, it legislates the surface. Paint it white, put a panel on it, rent it to a tower, and it becomes visible — as infrastructure, never as a room.

Which is a fair description of a great deal of ordinary life here. The important spaces are frequently the ones the forms do not have a box for, and the household's response is not to demand a box. It is to use the roof, quietly, for four months a year, and to build the stairhead a little higher each time there is money.

This is entry 9 of Everyday Life in About India. The pillar's argument — that the day is shaped by logistics, not by monuments — is set out on the pillar page.