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In common US usage, the heights of tall things are sometimes converted to a "number of stories". The thinking is that people can better compare heights to similar tall buildings that they might have seen.

The US conversion is usually: $$\text{Number of stories} = \text{Round}\Big(\frac{\text{height in feet}}{10}\Big)$$

I assume that something similar is used in metric countries like: $$\text{Number of storeys} = \text{Round}\Big(\frac{\text{height in meters}}{3}\Big)$$

I am assuming that like most things that are common usage, this conversion is not correct in practice.

What is a more accurate height of a building story?
How does this cause confusion when comparing the height of a building in "stories" to the actually number of stories?

hazzey
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1 Answers1

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There's a handy-dandy table here:

                                           Office      | Residential/hotel | Function Unknown 
                                                                             or Mixed-Use 
floor-to-floor height (f)                  3.9m        | 3.1m              | 3.5m 
Entrance lobby level floor-to-floor height 2.0f = 7.8m | 1.5f = 4.65m      | 1.75f = 6.125m 
Number of mechanical floors above ground   s/20        | s/30              | 2/25
(excluding those on the roof)

Height of mechanical floors                2.0f = 7.8m | 1.5f = 4.65m      | 1.75f = 6.125m 
Height of roof-level mechanical            2.0f = 7.8m | 2.0f = 6.2m       | 2.0f = 7.0m 
areas / parapets / screen walls

H = Building height
f = Typical occupied floor-to-floor height
s = Total number of stories

m = meters

These numbers are just averages.

Using this, it is possible to derive the height of an office building: $$H_{\text{office}}=3.9s+11.7+3.9(s/20)$$ The same can be done for a residential building: $$H_{\text{residential}}=3.1s+7.75+1.55(s/30)$$ The page then gives some comparisons of real buildings and the variation from the formula. However, while the "aggregate" variation for residential buildings (for example) comes out to 0.36%, a better indicator of accuracy would be to take the absolute value of the variation.

So, in summary: The average height depends on the function of the building (i.e. office vs. residential). But there are, of course, deviations from these figures.

HDE 226868
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