What is plot ratio and how to determine that the development is high or low density through plot ratio?

What does plot ratio means?

In simplified terms for explanation, a plot ratio is how much space you can build up on a particular piece of land, for example, for a piece of 10,000sqft land, if it has a plot ratio of 1:2, that means a building of 20,000sqft can be built on it.
This ratio is determined by the state authority.
But, on top of plot ratio, there are other considerations like set back area, height restrictions.......
There is not fixed definition on high and low density development, it is a relative comparisons between the number of units to the land size of a development

its counted as nett floor area or gross floor area?

Thanks @vince2602

gross floor area, the common area, service area, traffic circulation...included

Is there any plot ratio for a residential bungalow land? Can the owner tear down his old 1 story bungalow and built a 3 storey bungalow? What kind of approval he needs to get and from who?

plot ratio the lower the better?

Good input, follow this thread

Good input. However it's more relevant to property developers :)

Ya, great input by Vince. Correct me if I'm wrong. Plot ratio for the high rise dev is higher compared to the landed ones. Which means the landed that we own is lower compared to the specific high rise as its build upwards and all...

@JohnL 

Do you know what is the formula to calculate plot ratio? 

What ratio is considered low or high? Thanks

Plot ratio in every area is varies and all depending on the local authority planning,  zoning, category of land as well as purpose of use. 

@jordanchen1981 good sharing