HIGH RISE BUILDINGS-1

The interesting question is why does man want to build to the sky. What is there about the desire for domination, or to reach God, or for private pride — the Pyramids are an example of that, but the tall building is certainly another.

— Skyscrapers Introductory Interview with Philip Johnson

Before entering the world of high-rise security and fire life safety, it is important to define what constitutes a high-rise building and to review the development and utilization of these unique structures.

What Is a High-Rise Building?

A building is an enclosed structure that has walls, floors, a roof, and usually windows. “ A ‘ tall building ’is a multi-story structure in which most occupants depend on elevators [lifts] to reach their destinations. The most prominent tall buildings are called ‘ high-rise buildings ’in most countries and ‘ tower blocks ’in Britain and some European countries. The terms do not have internationally agreed definitions.

A high-rise building as defined in IBC as a “building with an occupied floor located more than 75 feet (22 860 mm) above the lowest level of fire department vehicle access.”

Unlike the standard building height dimension regulated by the IBC, the height for determining a high-rise building is determined by two different points of measurement:

1. The lowest level of fire vehicle access and

2. The highest occupied floor

National Building Code (NBC) defines a high-rise as "all buildings 15 m or above in height

NFPA defines - High-rise as a building 75 feet (23 m) or greater than measured from the lowest level of fire department vehicle access to the floor of the highest occupiable story.

ASHRAE Technical committee for Tall Building TC 9.12 has defined -"A Tall Building as one whose height is greater than 91m (300 feet)"

Tall Buildings as defined by Council On Tall Buildings And Urban Habitat

Buildings higher than 50m is termed as Tall Building.

Buildings higher than 100m is termed as skyscraper.

Buildings 300m or higher is termed as super tall.

Buildings 600m or taller is termed as mega-tall.

WHY TALL BUILDINGS?

Demand for high-rise Building

Scarcity of land in urban areas

Increasing the demand for business and residential space

Economic growth

Technological advancements

Innovations in structural systems

Desire for aesthetics in urban settings

Concept of city skyline

Cultural significance and prestige

Human aspiration to building higher

Today, most of the 50 tallest skyscrapers in the world are located in Asia. China is the fastest growing country in terms of skyscrapers. Dubai is ahead of any other city in Asia; there are more than 70 skyscrapers whose height exceeds 200 m

In 2010 Dubai unveiled the world's tallest building Burj Khalifa' 828 meters

The world's tallest is set to change yet again with the completion of the Kingdom Tower.

Mumbai the commercial and financial capital has most of the high-rise buildings in India

Hundreds of high-rises are already completed and several super tall buildings are under construction in Mumbai

Mumbai Skyline during Daytime Mumbai Skyline at Night

Mumbai would soon pride itself on being a "Mini-Manhattan" because of its emerging High-Rises.

CTBUH

The Council on Tall Buildings and Urban Habitat (CTBUH) developed the international standards for measuring and defining tall buildings, as outlined below, and is recognized as the arbiter for bestowing designations such as the “World’s Tallest Building.”

Tall Buildings There is no absolute definition of what constitutes a “tall building;” the definition is subjective, considered against one or more of the following categories:

1.Height Relative to Context

2.Proportion

3.Embracing Technologies Relevant

1.Height Relative to Context:

A 14-story building may not be considered a tall building in a high-rise city such as Chicago or Hong Kong, but in a provincial European city or a suburb this may be distinctly taller than the urban norm.

2. Proportion:

There are numerous buildings that are not particularly high, but are slender enough to give the appearance of a tall building. Conversely, there are numerous big/large-footprint buildings that are quite high, but their size/floor area rules them out of being classed as a tall building.

3. Embracing Technologies Relevant to Tall Buildings :

A building containing technologies which may be attributed as being a product of “tall” (e.g., specific vertical transport technologies, structural wind bracing as a product of height, etc.)

If a building can be considered as subjectively relevant to one or more of the above categories, then it can be considered a tall building. Although number of floors is a poor indicator of defining a tall building due to the changing floor to floor height between differing buildings and functions (e.g., office versus residential usage), a building of 14 or more stories – or more than 50 meters (165 feet) in height – could typically be used as a threshold for a “tall building.”

Measuring Tall Building Height

Three height categories are recognized. All categories measure the building from:

1. Height to Architectural Top

2. Height to Highest Occupied Floor

3. Height to Tip

1. Height to Architectural Top:

The architectural top of the building, including spires, but not including antennae, signage, flagpoles or other functional-technical equipment.5 This measurement is the most widely utilized and is employed to define the CTBUH rankings of the “World’s Tallest Buildings.”