A skyscraper is a very tall, building. The minimum height requirement currently to be accepted as skyscraper is 800 feet (244 meters). The word skyscraper was first known to such buildings in the late 19th century, which reflects public amazement at the tall buildings that are being built in New York City. The structural definition of the word skyscraper was later refined by architectural, historians, based on engineering developments of the 1880's that had enabled construction of tall multi-story buildings. This definition was based on the steel skeleton as opposed to constructions of load-bearing masonry, which passed their practical limit in 1891 with Chicago's Monadnock Building. Thus, this PDF deals with the construction and details of various skyscrapers along with their advantages and challenges both technically as well as in general perception. Necessary diagrams are given along with proper explanations.

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INTRODUCTION
A skyscraper is a very tall, building. The minimum height requirement currently to be
accepted as skyscraper is 800 feet (244 meters). The word skyscraper was first known to such
buildings in the late 19th century, which reflects public amazement at the tall buildings that
are being built in New York City. The structural definition of the word skyscraper was later
refined by architectural, historians, based on engineering developments of the 1880s that had
enabled construction of tall multi-story buildings. This definition was based on the steel
skeleton as opposed to constructions of load-bearing masonry, which passed their practical
limit in 1891 with Chicago's Monadnock Building. The steel frame developed in stages of
increasing self-sufficiency, with several buildings in New York and Chicago advancing the
technology that allowed the steel frame to carry a building on its own. Today, however, many
of the tallest skyscrapers are built more or less entirely with reinforced concrete. In the United
States today, it is a loose convention to draw the lower limit on what is a skyscraper at 153
metres (500 feet). Thus, calling a building a skyscraper will usually, but not always, imply
pride and achievement. Though never made famous, the Incans made a feeble attempt to build
the first skyscraper. This skyscraper, was to be called "UtzaInti" which can be translated to
"road to the sun god Inti." In 1440 the Incan emperor Bhutilishus II commissioned 2,000
slaves from the nearby province of Uhrhythrah to begin a 1000 foot tower. The tower was to
have one room called a LintzaTianu. Construction began in approximately 1442 under the
royal architect, whom priests called Tahmihpohn Puhpuhsi or, "builder of our empire."
Construction on the building occurred for three years until an earthquake destroyed the base of
the structure. All efforts to rebuild the tower were ignored.
A skyscraper taller than 305 metres (1,000 feet) may sometimes be referred to as a supertall.
The crucial developments for skyscrapers were steel, reinforced concrete, water pumps, and
elevators. Until the 19th century, buildings of over six stories were rare. So many flights of
stairs were impractical for inhabitants, and water pressure was usually insufficient to supply
running water above about 15 metres (50 feet). [2]

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ABSTRACT
Skyscrapers are known to be super tall building either residential, work place or of mix use.
They are now tends to coincide with major downturns in the economy. Today the number of
skyscrapers that are being built all around the world are increasing where the land is highly
expensive (as in big / metropolitan cities) as they provide high ratio of floor space to be used
to per unit area of available land. They are not built just for the economy of space, they are
considered to be symbol of city’s economic power. They do not only define the skyline but
also defines the city’s identity. In many places exceptionally tall skyscrapers have been built
not just because of necessity of space but to define the city’s identity and presence of power as
a city. The first skyscrapers would have been typically an office building of more than 10
storeys. The concept was undoubtedly originated in the USA, in Chicago and in New York,
where space was limited and where the best option was to increase the height of the buildings.
The crucial developments for skyscrapers were steel, reinforced concrete, water pumps, and
elevators. Until the 19th century, buildings of over six stories were rare. So many flights of
stairs were impractical for inhabitants, and water pressure was usually insufficient to supply
running water above about 15 metres (50 feet). The weight-bearing components of skyscrapers
differ substantially from those of other buildings. Buildings up to about four stories can be
supported by their walls, while skyscrapers are larger buildings that must be supported by a
skeletal frame.

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Review of Literature
DEVELOPMENT OF MODERN SKYSCRAPERS
In the late 19th century, the first skyscrapers would have been typically an office building of
more than 10 storeys. The concept was undoubtedly originated in the USA, in Chicago and in
New York, where space was limited and where the best option was to increase the height of the
buildings. The Home Insurance Building in Chicago was perhaps the first skyscraper in the
world. Built in 1884-1885 its height was 42 m/10 storeys. Designed by Major William Le Baron
Jenney, a graduate of l’EcoleCentrale des Arts et Manufactures de Paris, the structural skeleton
was a bolted steel frame without bracing supporting the loads coming from the walls and the
slabs, founded on a raft. This led to what is known as the “Chicago Skeleton”. [1]
.

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Methodology
STRUCTURE, MATERIAL AND BUILDING TECHNIQUE
Foundations and the Excavation Pit
Skyscraper foundations are considerably more complex than those for normal buildings. The
complexity brought is just because of their height and weight and can be further depend on the
certain specific factors such as nature of soil, exposure to wind , earthquake and their location in
relation to surrounding property. Depending on the nature of the structure, the type of foundation
and the characteristics of the ground, the value of the foundation / excavation can be as much as
the 7.5% of the total project value.
The foundation is the supporting layer of a structure. The main purpose of the foundation is to
transfer the various loads (wind, seismic, dead and live) from the structure into the ground.
Different factors can influence the type and dimension of the foundations; soil type and
stiffness, water content, void ratio, bulk density, angle of repose, cohesion, porosity to name but
a few. Characteristics of the ground can also experience change due to the geological history or
previous construction activities. [8]
There are many different types of retaining walls:
• Interlocking sheet piles; these can be temporary or permanent
• Contiguous, secant piled walls, the latter more likely to be used in soft/wet soils
• Diaphragm walls; particularly used in soft ground with high groundwater and/or adjacent
to other structures
• Crosswalls; often used in addition to one of the above where is a particularly high
exposure to adjacent properties
Typically in the case of coverage for skyscrapers clauses should be considered which address the
following specific areas:
• Piling
• Dewatering
• Vibration, weakening or removal of support

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• Dilapidation
Figure 1: Shanghai, China :
Possible failure of the
foundation
Figure 2: Moscow, Russia:
Excavation / cantilevered
walls

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Structure of the Main Skeleton, Design and Material
Of the 100 tallest buildings the number using steel has reduced by at least 15% each decade since
1970, and in 2010 only 22% of the tallest building is steel.
The key issues with high performance concrete (high performance concrete is reinforced
concrete with a compressive strength at 28 days in excess of 50 MPa) relate to the quality of the
material and the expertise of the contractors. Only a few of whom are familiar with these
concretes. The controls on site must be quite strict and without compromise. The columns of The
Coeur Defense towers in the business district of Paris have a diameter of 1,10m and used a high
performance concrete of 80 MPa.
When it comes to steel, the quality of the material is with the suppliers. On site the main concern
will be on the various assemblies. This is like giant meccano, however as often these projects
take place in a confined urban environment, logistics and third party exposures are an important
consideration.[8]
In respect of structural systems, it is possible to define 6 categories:
1. The framed tube: system of rigid frames (flatiron building in 1903)
2. The bundled tube: combination of framed tubes (Sears towers, 1974)
3. Tube in tube: central and peripheral tubes (World Trade Centre in NY, 1972)
4. Diagonalised: stressed tubes, diagrids/braced frames (Alcoa bld. in Chicago)
5. Core plus outrigger: central lateral system linked to the perimeter system through
outriggers (PETRONAS Tower, 1999 –Taipei 101, 2003 )
It is however important for a construction underwriter to look at the problems emerging from
these loads (earthquake or wind) during the various construction stages. The wind analysis is
very often conducted with a view to understanding how the building will behave when it is
completed. However for example the cladding of the building may require further tests to make
sure that during the construction stages, the wind load distribution will not generate unexpected
problems.[8]

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Various types of skeleton structures:
Superframe Steel frame Vertical
Truss
Tube in Tube Bundled tube
Exterior braced
frame tube
Steel tube Steel Frame/Belts Tuned Mass Damper

8. 
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System
The façade / cladding systems comprise the external building envelope or the outer finish. These
have evolved over time to reflect the ambitions of the developers and the creative and innovative
talents of the modern architects.
Key factors which will affect the characteristics of the cladding / façade systems include;
climatic conditions, support and anchorage systems, owner’s “taste”, maintenance services,
ventilation or air-circulation system. The dimensions of the individual external wall elements,
forming part of the external building envelope, are designed to fit between two respective
structural floors, the main objectives being:
• Water-tightness, Aesthetics, Wind, Privacy
• Thermal protection (including control of sunlight entry),
• Reduction in noise-level, and Strength / durability.
There are four different groups and their sub-groups of Façade systems / Cladding systems
existing. They are (though not an exhaustive list):
• Traditional
- Brick façade (e.g. Empire State building, Chrysler building, etc.)
- Marble panel system
• Ventilated Façade
- Aluminum, stone, ceramics, fibre reinforced concrete
• (Non-load bearing) Curtain wall
• Glass
Material Weights
Flat glass used for window panels – the weight depends on the glass thickness:
 ¼ of an inch thick glass weighs about 3lbs/ft²
 ½ of an inch thick glass weighs about 6.4lbs/ft²

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Adding coatings to the glass in order to protect it and tint, would also increase the weight of the
glass panel.[8]
Building Material
• Aluminum – has become the material-of-choice for the outer frames.
• Window Panes – made of high-grade glass filled with noble gases and a surface coating
in order to reflect infrared light.
• Laminated Glass
• “Sandwich” Panels – one of the primary materials used in façade systems of a building
are so called “sandwich” panels or also known as “composite” panels.
- Sandwich or Composite panels are thermal insulating material. These panels
consist of two thin metal facings/sheets (i.e. outer “skin”), usually steel or
aluminum, bonded to an inner core of thermal insulating material of varying
thickness. This system includes joints and supports. The combustible panels
include:Expanded Polystyrene (EPS), Extruded Polystyrene (XPS), Polyurethane
(PUR), Polyisocyanurate (PIR), Phenolic Foam (PF)
- The non-combustible panels include: Mineral Wool, Rock Fibre (MWRF), Glass
fibre (MWGF), Foamed Glass (Cellular Glass)
• There is great interest in the combustible-type panels because they are the most widely
used in buildings like apartment/residential, hotels, office/commercial, hospitals.
• The combustible panels are widely used / installed in countries situated in the Middle
East and the Arabian Gulf peninsula due to the harsh climatic conditions, characterized
by high temperature all year-long especially between June and September. The most
widely used panels are the polystyrene and the polyurethane panels for many reasons, to
name a few (a) low installation cost, (b) easy in handling and installation, and (c)
strength/durability. [8]
WIND LOADS
Wind engineering analyzes effects of wind in the natural and the built environment and studies
the possible damage, inconvenience or benefits which may result from wind. In the field of
structural engineering it includes strong winds, which may cause discomfort, as well as extreme

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winds, such as in a tornado, hurricane or heavy storm, which may cause widespread destruction.
In the fields of wind energy and air pollution it also includes low and moderate winds as these
are relevant to electricity production resp. dispersion of contaminants.
Wind engineering draws upon meteorology, fluid dynamics, mechanics, geographic information
systems and a number of specialist engineering disciplines including aerodynamics,
and structural dynamics.
Wind engineering involves, among other topics:
• Wind impact on structures (buildings, bridges, towers).
• Wind comfort near buildings.
• Effects of wind on the ventilation system in a building.
• Wind climate for wind energy.
• Air pollution near buildings.
Wind engineering may be considered by structural engineers to be closely related to earthquake
engineering and explosion protection.[8]
SEISMIC LOADING
Seismic loading is one of the basic concepts of earthquake engineering which means application
of an earthquake-generated agitation to a structure. It happens at contact surfaces of a
structure either with the ground, or with adjacent structures, or with gravity waves from tsunami.
Seismic loading depends, primarily, on:
• Anticipated earthquake's parameters at the site - known as seismic hazard
• Geotechnical parameters of the site
• Structure's parameters
• Characteristics of the anticipated gravity waves from tsunami (if applicable).

11. 
Sometimes, seismic load exceeds ability of a
or completely. Due to their mutual
astructure are intimately related.
SE
IS
MI
C
PE
RF
OR
M
AN
CE
Earthquake or seismic performance
such as its safety and serviceability
normally, considered safe if it does not endanger the lives and well
by partially or completely collapsing. A structure may be considered
fulfill its operational functions for which it was designed.
Basic concepts of the earthquake engineering, implemented in the ma
that a building should survive a rare, very severe earthquake by sustaining significant damage
but without globally collapsing
frequent, but less severe seismic events.
Sometimes, seismic load exceeds ability of a structure to resist it without being broken, partially
Due to their mutual interaction; seismic loading and seismic performance
are intimately related. [10]
seismic performance defines a structure's ability to sustain its main functions,
serviceability, at and after a particular earthquake exposure. A structure is,
if it does not endanger the lives and well-being of those in or around it
by partially or completely collapsing. A structure may be considered serviceable
fulfill its operational functions for which it was designed.
Basic concepts of the earthquake engineering, implemented in the major building codes, assume
that a building should survive a rare, very severe earthquake by sustaining significant damage
but without globally collapsing. On the other hand, it should remain operational for more
frequent, but less severe seismic events.

to resist it without being broken, partially
seismic performance of
defines a structure's ability to sustain its main functions,
a particular earthquake exposure. A structure is,
eing of those in or around it
serviceable if it is able to
jor building codes, assume
that a building should survive a rare, very severe earthquake by sustaining significant damage
On the other hand, it should remain operational for more

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VIBRATION CONTROL
In earthquake engineering, vibration control is a set of technical means aimed to
mitigate seismic impacts in building and non-building structures.
All seismic vibration control devices may be classified as passive, active or hybrid where:
• Passive control devices have no feedback capability between them, structural elements and
the ground;


• Hybrid control devices have combined features of active and passive control systems.
When ground seismic waves reach up and start to penetrate a base of a building, their energy
flow density, due to reflections, reduces dramatically: usually, up to 90%.
• To dissipate the wave energy inside a superstructure with properly engineered dampers;
• To disperse the wave energy between a wider range of frequencies;
• To absorb the resonant portions of the whole wave frequencies band with the help of so-
called mass dampers.
Devices of the last kind, abbreviated correspondingly as TMD for the tuned (passive), as AMD
for the active, and as HMD for the hybrid mass dampers, have been studied and installed in high-
rise buildings, predominantly in Japan, for a quarter of a century.
In refineries or plants snubbers are often used for vibration control. Snubbers come in two
different variations: hydraulic snubber and a mechanical snubber.
• Hydraulic snubbers are used on piping systems when restrained thermal movement is
allowed.
• Mechanical snubbers operate on the standards of restricting acceleration of any pipe
movements to a threshold of 0.2 g's, which is the maximum acceleration that the snubber will
permit the piping.[10]

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CONSTRUCTION TECHNIQUES
The weight of a skyscraper mainly consists of dead load, the load exerted by the building itself.
Any extra weight from people, furniture, vehicles, etc. is known as live load. In addition, wind
and other unexpected sources can be load providers. The design of a skyscraper is mainly
dictated by how the total load is to be distributed. Skyscraper designs are categorized as steel
frames, shear walls, concrete core, or tube designs.
SHEAR WALLS
In a shear wall design, the weight of the structure
is distributed through the walls. These structures
are often made of steel reinforced brick or cinder
block–materials with high compressive strength.
The shear wall design is primarily used in small
projects such as urban brownstones or suburban
housing. As the load exerted on the building
increases, shear walls must increase in bulk,
meaning skyscrapers would need considerably large walls. Because of this, for tall buildings, this
system is only used in conjunction with other supporting systems.
STEEL FRAME
When one thinks of low-rise skyscrapers, the steel frame design comes to mind. This design is
characterized by a large steel box, containing smaller steel boxes inside. This 3D grid is simple
and efficient for most low-rises, but has its’ drawbacks for high-rise structures. As the building’s
height increases, the space between steel beams must decrease to compensate for the extra
weight, resulting in less office space and the need for more material.
TUBE FRAME
The tube design is a recent innovation used to maximize floor space and increase resistance to
lateral force in any direction. The buildings skin (outside) consists of closely aligned supporting

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columns. This design only leaves about one-half of the building’s exterior left for windows.
Depending on the designer’s outlook, this can be an advantage or disadvantage. The decreased
window space helps those who suffer acrophobia (a fear of heights) comfortably occupy the
space; however, it decreases the visibility and openness offered by other designs.
The tube frame design was made popular by the World Trade Centers, whose ultimate failure;
some believe was due to the tube frame design[8]
CONCRETE CORE
This is the most common design for modern skyscrapers as it
is fast to build and provides a strong center. All the utilities,
elevators, and stairwells are centralized in this design,
making it easier for building modifications and repair. This
design can be dangerous. If a part of the core is damaged,
everything above that section will be cut off from ground
access. This happened in the World Trade Center towers
during the September 11, 2001 terrorist attacks, making it
impossible for many people to escape the burning towers.
EARTHQUAKE RESISTANT CONSTRUCTION
REINFORCED MASONRY STRUCTURES
A construction system where steel reinforcement is embedded in the mortar joints of masonry or
placed in holes and after filled with concrete or grout is called reinforced masonry.
The devastating 1933 Long Beach earthquake revealed that masonry construction should be
improved immediately. Then, the California State Code made the reinforced masonry mandatory.
To achieve a ductile behavior of masonry, it is necessary that the shear strength of the wall is
greater than the flexural strength.

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Reinforced hollow masoary wall
Reinforced Concrete Structures
Reinforced concrete is concrete in which steel reinforcement bars (rebars) or fibers have been
incorporated to strengthen a material that would otherwise be brittle. It can be used to
produce beams, columns, floors or bridges.
Prestressed concrete is a kind of reinforced concrete used for overcoming concrete's natural
weakness in tension. It can be applied to beams, floors or bridges with a longer span than is
practical with ordinary reinforced concrete. Prestressing tendons (generally of high tensile steel
cable or rods) are used to provide a clamping load which produces a compressive stress that
offsets the tensile stress that the concrete compression member would, otherwise, experience due
to a bending load.[10][11]

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Stressed Ribbon pedestrian bridge over the Rogue River, Grants Pass, Oregon
Prestressed concrete cable-stayed bridge over Yangtze river
PRESTRESSED STRUCTURES
Prestressed structure is the one whose overall integrity, stability and security depend, primarily,
on prestressing. Prestressing means the intentional creation of permanent stresses in a structure
for the purpose of improving its performance under various service conditions.
Naturally pre-compressed exterior wall of Coliseum, Rome

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There are the following basic types of prestressing:
• Pre-compression (mostly, with the own weight of a structure)
• Pretensioning with high-strength embedded tendons
• Post-tensioning with high-strength bonded or unbonded tendons
Today, the concept of prestressed structure is widely engaged in design of buildings,
underground structures, TV towers, power stations, floating storage and offshore
facilities, nuclear reactor vessels, and numerous kinds of bridge systems.
STEEL STRUCTURES
Steel structures are considered mostly earthquake resistant but this isn't always the case. A great
number of welded Steel Moment Resisting Frame buildings, which looked earthquake-proof,
surprisingly experienced brittle behavior and were hazardously damaged in the 1994 Northridge
earthquake. After that, the Federal Emergency Management Agency (FEMA) initiated
development of repair techniques and new design approaches to minimize damage to steel
moment frame buildings in future earthquakes. For structural steel seismic design based on Load
and Resistance Factor Design (LRFD) approach, it is very important to assess ability of a
structure to develop and maintain its bearing resistance in the inelastic range. A measure of this
ability is ductility, which may be observed in a material itself, in a structural element, or to
a whole structure.
PREFABRICATION
Prefabrication is the practice of assembling components of a structure in a factory or
other manufacturing site, and transporting complete assemblies or sub-assemblies to
the construction site where the structure is to be located. The term is used to distinguish this
process from the more conventional construction practice of transporting the basic materials to
the construction site where all assembly is carried out.

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The term prefabrication also applies to the manufacturing of things other than structures at a
fixed site. It is frequently used when fabrication of a section of a machine or any movable
structure is shifted from the main manufacturing site to another location, and the section is
supplied assembled and ready to fit. It is not generally used to refer to electrical or electronic
components of a machine, or mechanical parts such as pumps, gearboxes and compressors which
are usually supplied as separate items, but to sections of the body of the machine which in the
past were fabricated with the whole machine. Prefabricated parts of the body of the machine may
be called 'sub-assemblies' to distinguish them from the other components.[10][11]
Advantages of Prefabrication
1. Self-supporting ready-made components are used, so the need for formwork, shuttering
and scaffolding is greatly reduced.
2. Construction time is reduced and buildings are completed sooner, allowing an earlier
return of the capital invested.
3. On-site construction and congestion is minimized.
4. Less waste may occur
5. Advanced materials such
as sandwich-structured
composite can be easily
used, improving thermal and
sound insulation and air
tightness.[11]

19. 
BurjKhalifa – Dubai (2010) 829 m
Key Facts: -
• Constructed in 6 years.
• World’s tallest building.
• 163 Storeys.
• 45,000 square meters of concrete
weighing 110,000 tonnes
• 12,000 workers.
• Cost USD $1.5billion.
• Tallest service elevator.
• Tallest free standing structure
• 31,400 metric tonne of steel used.
• Construction started in 2004
• 58 number of elevators
• Top elevator speed 10m/s
• 900 number of apartments
• Previously known as Burj Dubai.
• Highest outdoor observation Deck
(440m)
• Peak Electricity demand of tower is 5
MVA
• 946,000 litres of water used every day.
• The tower’s architect and engineer is Skidmore, Owings and Merrill (Chicago).
Discussion
Dubai (2010) 829 m
Constructed in 6 years.
World’s tallest building.
45,000 square meters of concrete
weighing 110,000 tonnes
Cost USD $1.5billion.
Tallest service elevator.
structure
31,400 metric tonne of steel used.
Construction started in 2004
58 number of elevators
Top elevator speed 10m/s
900 number of apartments
Previously known as Burj Dubai.
Highest outdoor observation Deck
Peak Electricity demand of tower is 50
946,000 litres of water used every day.
The tower’s architect and engineer is Skidmore, Owings and Merrill (Chicago).

The tower’s architect and engineer is Skidmore, Owings and Merrill (Chicago).[3][4]

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The Imperial II (Mumbai) 2010 254m
Key Facts:-
• Tallest building in India
• Tallest Residential Building in India.
• Also called as SD Towers orTardeo Twin
Towers.
• 60 floors.
• Construction started in 2005
• #189 tallest in World
• #17 Elevators.
• Top elevator speed 6m/s.
• A private observation deck is present at the
top of each building by the cone spires.
• Use of M50 grade cement which is usually
used in building dams and bridges.
• 228 luxury homes.
• Fe 500 iron used instead of regular Fe 450
to give the slabs added tensile strength
allowing longer spans in between the
beams.
• Clear ceiling height of 10.8 and 11.8 feet.
• A grand triple height lobby.[8]

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SKYSCRAPERS – IMPLICATIONS
Advantages of Skyscrapers
Throughout the world, the population of the major cities are increasing at a fast rate and where
land for building is not available; there is a pressure to build upward rather than sideways.
The main advantage of building higher building is that they can take pressure of the need to build
just outside large cities, thus preventing the spread outwards and the destruction of the
countryside. In smaller countries, land is very expensive and so it makes a sense to build
upwards. In London for example property prices are rising rapidly and will continue to do so for
years to come unless more homes are built. Options, building in the greenbelt area around the
city and constructing skyscrapers are controversial, but tall buildings are the less damaging
alternative. Here are few more advantages of Skyscrapers.
• Skyscrapers are known as modern answer for lack of space.
• Each Skyscraper has their own unique architectural feature.
• These features often made the skyscrapers the icon of their city.
• These skyscrapers attract millions of tourist each year, and bring profit to local business.
• Radio, television and cell phones require signal receivers from broadcasters.
• By placing an antenna at a highest point in the city broadcasters can send a power full
signal for many miles.
• Skyscrapers provide excellent site for antenna and other equipment.

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Disadvantages Of Skyscrapers
People have been building towers for as long as there have been cities. From the watchtowers
and temple spires of ancient cities to the skyscrapers and radio towers that form the most modern
skylines, towers represent the on-going evolution of architectural and engineering techniques.
The structures offer some major advantages but also pose serious challenges to designers and
builders.
• High cost of investment, construction, maintenance, and operation.
• Negative effect on indoor and outdoor environment.
• Destruction of natural environment.
• Noise pollution.
• Poor Ventilation.
• Rely on Elevators.
• Fireproofing Problem.
• Evacuation difficulty when fire broke out.
• Poor Fire resistance of Steel Structure System.
• Land Subsidence.
• The development of high rise buildings destroyed the harmony of the local cultural
landscape.
• The last reason is economy; the skyscrapers can’t be cleaned or repaired by normal
people.
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CONCLUSION
Why were these buildings suddenly getting bigger and who was actually occupying them? The
answer is that there was this huge social change in the office world in the early twentieth century.
The need for office workers was expanding at a spectacular rate as businesses like banking,
insurance, and law firms hired more people, not only the partners at these firms but huge
numbers of office workers too. Both men and women were being hired and so they needed more
space.
In addition to the large businesses, there were many smaller support businesses that rented small
offices in these speculative office buildings. But the number of these businesses expanded
enormously. If business had not been expanding, this skyscraper development would never have
occurred because these are money generators. The builders of these skyscrapers wanted to make
a profit and they had to know that there was an office market out there to rent the space, because
if there was no office market, what was the point of investing money in constructing such a large
building if it was just going to remain vacant? So it was the expansion of the office market that
went hand in hand with the expansion of the skyscraper.

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RECOMMENDATION
I would like to say that it is a great technology in Construction Engineering. With this
technology very light and durable structure is possible with a lot more space for activities.
But, we have to take care of the environment and surroundings also so that the materials and the
technologies used should be green and have minimum impact on the environment. They are not
just built for the economy of space but they are considered as a symbol of a city’s Economic
Power.
Now, as we see all the different types of buildings and structures in our own city, we will have a
greater knowledge about the materials used to build them, their strength and safety, and the
serious thought that went into their design and construction.

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BIBLIOGRAPHY
1. www.imia.com/downloads/imia_papers/WGP76_2012.pdf
2. http://www.burjkhalifa.ae/en/TheTower/FactsFigures.aspx
3. http://yeinjee.com/burj-khalifa-dubai-facts-figures/
4. http://history1900s.about.com/od/1930s/a/empirefacts.htm
5. http://www.allaboutskyscrapers.com/culture/skyscraper_design
6. http://www.skyscrapercenter.com/mumbai/the-imperial-ii/
7. Mark Thorton’s Skyscrapers and Business Cycle Edition 2005.
8. CTBUH Height Criteria". Council on Tall Buildings and Urban Habitat
9. Skyscrapers by Andres Lepik 2004
10. Man made Wonders Skyscrapers by Jason Cooper Rourkee Enterprise
11. Skyscraper (building)". Britannica.com. 11 September 2001