The most prominent feature of the Harappan era architecture is the drainage system. It shows how important cleanliness was for them, and it was achieved through having a series of drains running along the streets that connected to larger sewers in the main streets.
Smaller drains from household latrines and bathing areas connected to these larger drains, which had corbelled roofs so they could be buried underneath the main streets when required without caving in.
Some sections had removable brick paving or dressed stones on top to allow cleaning when required. Drains exiting the city even had wooden doors that were probably closed at night to prevent vagrants or negative elements from entering the city through that access.
Sump pits were found at intervals along the drains which allowed heavier solid waste to collect at the bottom. These were regularly cleaned to avoid blockages.
Varying types of houses and buildings are found in both large and small settlements. Rural areas tend to have exclusively mud brick buildings whereas urban areas have buildings partially or wholly made of baked bricks. Small and large houses and public buildings are the main categories.
Houses range from 1-2 stories in height, with a central courtyard around which the rooms are arranged. The interior is not visible from the street, shut off using corridors or walls on the inside.
Openings are also restricted to side streets to maintain privacy on the inside of the houses. Stairs led to the upper stories through a side room or the courtyard and the size of foundations has shown that a third floor might also have existed at one point.
The average thickness of walls was 70cm and the average ceiling height about 3 meters. Doors were made of wood with wooden frames and the pivot was a brick socket set in the threshold.
Door frames were possibly painted and simply ornamented and also had holes at the base and two at the top of the door to secure and hang curtains respectively. The windows had both shutters and grills, which were embedded into the building itself.
Grills might have been of reed or matting but alabaster and marble latticework has also been found suggesting that although it was a common feature of houses, the more refined ones were obviously kept for the more affluent homes.
This element continued to be used through the historical era into modern times as well.
Larger houses had smaller dwellings connected to them and evidence of repeated rebuilding in the interior shows that the internal spaces were constantly reorganized. Whether the adjoining dwellings were for extended family or servants cannot be accurately ascertained at this time.
Large public buildings are the third major category and include both public spaces such as markets, squares and courtyards, and administrative buildings including granaries. The great hall or great bath structures are also a part of this serving possibly a religious as well as a social function.
Groups or clusters of houses are also in evidence, which probably housed several families together and had their own facilities such as latrines and bathing areas as opposed to using the communal facilities.
Wells & Sanitation
Drinking water or water, in general, was made available in abundance to the people of Harappa to the very close proximity of the city to the pre-Indus Gaggar/Hakra River which allowed fewer water wells to serve the people as the majority could attain their water from the river itself.
There is also found in Harappa a central depression that might have been a public pool for drinking and washing which allowed wider access to the resource. As a result, there are a few wells at Harappa totaling perhaps a total of only 30 wells as compared to 700 or more at Mohenjo-daro.
There are more private than public wells, which points to the fact that the public wells probably got polluted or run out due to heavy use and affluent citizens then dug their own.
Bathing rooms in these houses were situated next to the well which itself was raised above ground level. Bathing rooms had tightly fitted brick floors which made them more or less waterproof.
Drains from these rooms led separately to the main drains on the outside from the latrine drains, and care was taken to separate the water and sewage drains.
The drains were tapered out into the street. Almost every house in Harappa has been found to contain a latrine which was a large terracotta jar sunk into the ground and sometimes connected to the external drains.
There was a granary, lying on a massive mud brick foundation with a rectangular plan of 50m x 40m, with the length corresponding to the North-South axis.
The foundations point to a total of 12 rooms in two rows (6 rooms per row) divided by a central passageway that is 7m wide and partially paved with baked bricks.
Each room measures approx. 15m x 6m and has three walls at the long ends with air between them pointing to hollow floors. The main structure would probably have been of wood built on these foundations with stairs leading up from the central path.
There have also been found triangular openings in the floor which might have been air ducts to remove moisture from the inside. The evidence for this being a granary has not been found during excavations and is mostly based on comparisons with Roman building techniques and does not coincide with local traditions.
It can be said that this “granary” was probably a public or state building for rulers or administrators or for other purposes related to the everyday workings.
The main materials used were sun-dried and burnt bricks, which were made in molds of 1:2:4 ratios. Easy availability of wood for burning meant baked bricks were used in abundance in Harappa and Mohenjo-daro.
Mud mortar and gypsum cement are also in evidence, and mud plaster and gypsum plaster are also found to have been used. Mud mortar is most evident at Harappa. Wooden frames were probably used for the doors and windows which have since rotted away.