The architecture of Indus Valley Civilization can be witnessed from the structures of Mohenjo-Daro. This city of Mohenjo-Daro was found by the archaeologist. These structures came into existence at the time of the Harappan city.
Even at such a premature age, the architecture of Indus Valley was well improved equipped with almost all the modern amenities. The architectural remains of the Indus Valley Civilization have also well been a witness of the sharp acumen of the architects belonging to such an early age.
The Architecture Like During Indus Civilization
Archaeological evidence from Mehrgarh in 7000 BCE shows the construction of mud-brick houses and granaries. Irrigation was very well developed in the Indus Valley Civilization around 4500 BCE. The size and prosperity of the Indus civilization grew as a result of this innovation. This innovation eventually led to more planned settlements which further made use of drainage and sewers.

By 2800 BCE, private bathrooms could be found in almost all the houses of the Indus Valley Civilization. These private bathrooms were located on the ground floor. The pottery pipes in walls allowed drainage of water. At some places, the provision of a crib for sitting was also made. The Indus Valley Civilization had some of the most advanced private lavatories in the world.
Irrigation System
“Western-style” toilets were made from bricks using toilet seats made of coal on top. The waste was then transmitted to drainage systems. Sophisticated irrigation and storage systems were developed by the Indus Valley Civilization.

These included the artificial reservoirs at Girnar in 3000 BCE which had an early canal irrigation system around 2600 BCE.
Sewer Systems
Additionally, large-scale sanitary sewer systems were in place in the Indus Valley by 2700 BCE. The drains were 7-10 feet wide and 2 feet which are 0.61 meters below ground level. The sewage was then led into cesspools. These cesspools were built at the intersection of two drains. Additionally, it also had stairs leading to them for periodic cleaning. The plumbing was done using earthenware plumbing pipes with broad flanges.
This was done for easy joining with asphalt to stop leaks was in place by 2700 BCE. The cities of Indus valley appear to have been carried out with some kind of systematic planning. In Mohenjodaro, the streets ran in straight lines. They were crossed by others exactly at right angles.
This bears a testimony to the level of planning. Also, the existence of some authority controlling the development of the city cannot be refuted. Town-planning was also accompanied with strict enforcement of building regulations. This was the greatest care was taken to prevent any structure from encroaching upon the streets.

The people seemed to have been extremely wealthy. This can be judged from the excellent masonry and carefully built houses. In the Indus Valley-Architecture, throughout the area, civic planning was based on a rectangular grid. This grid was orientated to the cardinal points and standardized brick was the main building material. A high proportion of the population lived in substantial, well-drained courtyard houses.
Wide streets and thoroughfares were common. The buildings were made of burnt bricks which were devoid of decoration. There were no windows and the entrances were placed in narrow by-ways. There was a police system as the cities with the area were divided into wards for protection. There was two or more story in the buildings.
The pottery jars were used as cupboards. Probably there were wooden shelves also. Beds, stools, and boxes were used. Most of the cooking was done in the courtyards though there were small kitchens. Buildings in many street corners suggest hotels or eating houses. These were probably the places where merchants and others would have met to arrange business deals. Further, they also combined gossip with eating and drinking. Stone was used in frontier towns.
Drainage System
The streets were all aligned from east to west or from north to south. This was done as a north or south wind sweeps down a broad thoroughfare. This would suck the stagnant air out of the smaller streets and lanes running at right angles. Thus, this helped in amply ventilating them. Sanitation and cleanliness as bathrooms were used and proper drainage system was found in all buildings.
The spill-way of many of the channels used for drainage was stepped at varying angles. This was done to ensure that the water pouring down should not splash the passer-by in the street. Each and every street had its brick-lined drainage channel and small lanes. Through these ran smaller tributary drains from the houses on either side. The wastewater and sewage from the various houses first passed into a sump or cess-pit in which the solid matter was deposited.

When the sump was three-quarters full, the water flowed into the larger drains. By this method overflowing was prevented. Large brick culverts were constructed on the outskirts of the city. These culverts carried away stormwater. Excellent sanitary engineering was followed at that time. Excellent water-supply was maintained as wells were used.
The great public bath was made of burnt brick. This public bath measured thirty-nine feet three inches in length and twenty-three feet two inches in width. One could enter it by either end with the help of a staircase. A paved walk surrounded the top of the bath. The openings in the wall gave access to a cloistered walk continuing right around the bath.
There was a vertical manhole at the western end. This manhole made it possible to inspect and clear the passage. The water passed out through a culvert. To the east of the bath, there is a large well which is accessible to the main street outside.
Hypocaust System
There was an annex to the Great Bath as well. This annex suggested arrangements for hot air bathing with a hypocaust system of heating. To the north of the Great Bath, there were the group of bathrooms with staircases for the upper story. No door exactly faced the other. This made it impossible for anyone to see into the room from outside. Bathing was probably considered as an essential ritual of people of Indus valley.
The Indus valley civilization was deeply influenced by Mesopotamian ways. As a result, it was evident that every feature of Indus Valley will have a Mesopotamian influence including architecture.

Various features of Mohenjo-Daro include a wide range of ceramic and bronze objects. These resembled the ones from Sumerian sites. Even today many of the architectural features of Indus Valley are carried on and is seen in many of the Hindu shrines. These are truly some of the architectural marvels.
The Indus Valley civilization possessed a flourishing urban architecture. This is clear from the excavated remains. The major cities of this civilization, notably Mohenjodaro, Harappa, and Kalibangan, were laid out on a grid pattern. Further, it had provisions for an advanced drainage system. The residential buildings, which were serviceable enough, were mainly brick and consisted of an open patio flanked by rooms.
For monumental architecture, the most important evidence was the “sacred” tank. This tank was believed to be for ritual ablution and associated structures. Corbel vaulting which was arches supported by brackets projecting from the wall was known. To a limited extent, timber was used together with a brick. Whatever architectural ornamentation existed which must have either been brick or plaster.