Why the USSR had an odd number of steps between floors: an interesting explanation

Artifacts from the Soviet era that still surround us sometimes surprise us with unexpected patterns. For example, no matter what city you find yourself in, you might have noticed that the staircases always have an odd number of steps.

As OBOZ.UA found out, there was a very logical reason for this. It was hidden in the construction standards that were introduced in the Soviet Union in the 1960s.

The thing is that after coming to power, the CPSU General Secretary Nikita Khrushchev set out to provide the population with housing. And in order to build houses quickly, he needed clear standards by which construction teams would work. Of course, these standards were the same throughout the USSR.

They covered all the nuances. From the height of the ceilings, which was the minimum suitable for living quarters, to the number of steps in the entrances. An odd number was approved for safety reasons. There were no elevators in the Khrushchev buildings, so the staircases had to be safe enough to move around. And, as international experience has shown, it is the odd number of steps that minimizes the chance of stumbling.

The thing is that it's easier for our brain to control the movement up the stairs if it starts and ends on the same foot. And this is exactly what happens if the stairs have an odd number of steps.

Most often, staircases in Khrushchev buildings had spans of 9 steps. In this case, their height was successfully correlated with the height of the ceilings of 2.7 meters. The optimal step height is 15 cm, and to go from floor to floor, you need to overcome two flights of stairs with 9 steps each. With this ratio, the calculations converged.

An exception was made only for the first floor. To climb it, you need to overcome an even number of stairs - eight.

Subscribe to the OBOZ.UA channels in Telegram and Viber to keep up with the latest events.