The courtyard haveli

A haveli is usually described as a house arranged around a courtyard, which is true and useless. It is like describing an engine as a metal box with holes in it. The courtyard is a working part, and the way to see that is to follow the air.

What the courtyard is doing at night

In clear desert conditions the ground loses heat to the sky after sunset faster than the air does. A courtyard is a surface pointed at that sky. Its floor cools, the air in contact with the floor cools, and because cool air is denser it settles into the bottom of the shaft and stays there. By two in the morning the courtyard holds a pool of air several degrees cooler than the street outside the door.

That pool is the building's cold store, and it is spent the next day. As the sun heats the outer walls, the air in the courtyard stays cooler than the air on the roof and in the street. Warm air rises out of the courtyard, cool air is drawn in from the shaded north rooms and from vents at the base of the walls, and a slow circulation establishes itself through the whole house. Nothing in this system needs power or moving parts. It needs a vertical shaft, a heavy floor, and shade at the right hour.

The thick walls do the rest. At 400 to 600 millimetres of stone or fired brick, the outer wall takes six to ten hours to pass heat from the outside face to the inside face. Peak indoor temperature therefore arrives in the evening, when the family is on the roof and does not care. The wall is a delay line, and the delay is the comfort.

The screens are not ornament

Jaali — the pierced stone screens on the outer walls — are usually photographed as filigree. They are a solar control device. A screen cuts direct radiation while allowing air through, which is the one combination glass cannot do: glazing admits light and stops air, and it traps heat in the gap. A jaali admits roughly a third of the light and most of the breeze, and the small openings accelerate the air as it passes, which is why a room behind one feels cooler than its thermometer suggests.

The jharokha, the projecting balcony, does a related job from a different angle. It shades the wall below it, gives the household a place to sit outside the room but inside the privacy of the facade, and — in the Jaipur version — allows women to watch the street without being watched. Hawa Mahal is the extreme case: 953 of them stacked into a screen wall, built in 1799, with no rooms behind most of it. It is a viewing instrument, not a residence, and reading it as architecture-for-its-own-sake misses the point entirely.

Where the money went

The courtyard explains the plan. It does not explain why so many havelis are covered in painting. That belongs to a different system: the Shekhawati merchants who built between roughly 1860 and 1930, made their money in Bombay and Calcutta and Burma, and came home to build a house that would state, on its street facade, exactly how well they had done.

The frescoes are therefore advertising, and they are legible as advertising once you know the grammar. A railway train and a motor car say: I have seen the new world. A steamship says: my trade crosses water. A row of English gentlemen in top hats says: I deal with them. Religious imagery sits above the door, business imagery on the street wall, and the family's own portraits at eye level where a visitor stands. It is a CV in pigment, applied to a house that was already thermally complete without it.

This matters for how you look at one. The climate logic is the structure; the painting is a claim about status. They are both worth seeing, and they answer different questions. Conflating them produces the standard error of heritage writing, in which a building is praised for being beautiful when it was built to be cool.

Why the form did not survive

The courtyard house did not lose to a better climate strategy. It lost to land economics and to the ceiling fan. Once a plot could be sold by floor area, a central void became an expensive luxury; once a fan could move air for a few watts, the passive system looked like a lot of masonry for a modest result. Add piped water, which removed the courtyard's second job as the household's washing and washing-up space, and the case closed.

What replaced it — a deep narrow plot with rooms front and back and a light-well — is the same idea reduced to its minimum. That is not necessarily worse. A light-well with a fan and a cooler is more comfortable in May than a courtyard without either, and it uses a fraction of the land. But it has no thermal mass, so it also has no delay: when the power fails at four in the afternoon, the courtyard house is still cool and the light-well house is not.

How to read one

Enter and stand still for a minute before looking at anything. If the courtyard is doing its job you will feel a direction to the air — usually from the shaded side toward the sunny side, low down. Then look at the section, not the facade: how deep is the shaft relative to its width? A deep narrow courtyard cools better and shades more of the wall; a shallow wide one is easier to build and worse in June. Then find the water — a small tank or a wet floor in the centre is not decorative, it is an evaporative cooler, and its absence tells you the household had another source.

Only then look up at the painting, and ask what the owner was claiming. In a Shekhawati house the answer is usually specific enough to date the building to within a decade.

Entry 02 of Architecture. The stepwell (entry 01) is the same argument in public scale: a climate machine that was later mistaken for a monument.