Filter by
You must be a CTBUH Member to view this resource.
The current legal building name.
CTBUH collects data on two major types of tall structures: 'Buildings' and 'Telecommunications / Observation Towers.' A 'Building' is a structure where at least 50% of the height is occupied by usable floor area. A 'Telecommunications / Observation Tower' is a structure where less than 50% of the structure's height is occupied by usable floor area. Only 'Buildings' are eligible for the CTBUH 'Tallest Buildings' lists.
The CTBUH follows the United Nations's definition of Country, and thus uses the lists and codes established by that organization.
The CTBUH follows the United Nations's definition of City, and thus uses the lists and codes established by that organization.
A single-function tall building is defined as one where 85% or more of its usable floor area is dedicated to a single usage. Thus a building with 90% office floor area would be said to be an "office" building, irrespective of other minor functions it may also contain.
A mixed-use tall building contains two or more functions (or uses), where each of the functions occupy a significant proportion of the tower's total space. Support areas such as car parks and mechanical plant space do not constitute mixed-use functions. Functions are denoted on CTBUH "Tallest Building" lists in descending order, e.g., "hotel/office" indicates hotel function above office function.
Steel
Both the main vertical/lateral structural elements and the floor spanning systems are constructed from steel. Note that a building of steel construction with a floor system of concrete planks or concrete slab on top of steel beams is still considered a “steel” structure as the concrete elements are not acting as the primary structure.
Reinforced Concrete
Both the main vertical/lateral structural elements and the floor spanning systems are constructed from concrete which has been cast in place and utilizes steel reinforcement bars.
Precast Concrete
Both the main vertical/lateral structural elements and the floor spanning system are constructed from steel reinforced concrete which has been precast as individual components and assembled together on-site.
Mixed-Structure
Utilizes distinct systems (e.g. steel, concrete, timber), one on top of the other. For example, a steel/concrete indicates a steel structural system located on top of a concrete structural system, with the opposite true of concrete/steel.
Composite
A combination of materials (e.g. steel, concrete, timber) are used together in the main structural elements. Examples include buildings which utilize: steel columns with a floor system of reinforced concrete beams; a steel frame system with a concrete core; concrete-encased steel columns; concrete-filled steel tubes; etc. Where known, the CTBUH database breaks out the materials used in a composite building’s core, columns, and floor spanning separately.
Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the architectural top of the building, including spires, but not including antennae, signage, flag poles or other functional-technical equipment. This measurement is the most widely utilized and is employed to define the Council on Tall Buildings and Urban Habitat (CTBUH) rankings of the "World's Tallest Buildings."
Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest point of the building, irrespective of material or function of the highest element (i.e., including antennae, flagpoles, signage and other functional-technical equipment).
Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest occupied floor within the building.
The number of floors above ground should include the ground floor level and be the number of main floors above ground, including any significant mezzanine floors and major mechanical plant floors. Mechanical mezzanines should not be included if they have a significantly smaller floor area than the major floors below. Similarly, mechanical penthouses or plant rooms protruding above the general roof area should not be counted. Note: CTBUH floor counts may differ from published accounts, as it is common in some regions of the world for certain floor levels not to be included (e.g., the level 4, 14, 24, etc. in Hong Kong).
Number of Parking Spaces refers to the total number of car parking spaces contained within a particular building.
You must be a CTBUH Member to view this resource.
You must be a CTBUH Member to view this resource.
Construction Start
Completed
Usually involved in the front end design, with a "typical" condition being that of a leadership role through either Schematic Design or Design Development, and then a monitoring role through the CD and CA phases.
The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.
The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.
Other Consultant refers to other organizations which provided significant consultation services for a building project (e.g. wind consultants, environmental consultants, fire and life safety consultants, etc).
Material Supplier refers to organizations which supplied significant systems/materials for a building project (e.g. elevator suppliers, facade suppliers, etc).
You must be a CTBUH Member to view this resource.
Usually involved in the front end design, with a "typical" condition being that of a leadership role through either Schematic Design or Design Development, and then a monitoring role through the CD and CA phases.
The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.
The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.
The main contractor is the supervisory contractor of all construction work on a project, management of sub-contractors and vendors, etc. May be referred to as "Construction Manager," however, for consistency CTBUH uses the term "Main Contractor" exclusively.
Other Consultant refers to other organizations which provided significant consultation services for a building project (e.g. wind consultants, environmental consultants, fire and life safety consultants, etc).
Material Supplier refers to organizations which supplied significant systems/materials for a building project (e.g. elevator suppliers, facade suppliers, etc).
Twisting Tall Buildings
18 August 2016 - CTBUH Research
Located at a prominent location in the heart of the Dafna Area overlooking the corniche, Al Bidda Tower’s dramatic twisting face makes it unique amongst the other towers of the Doha skyline. The rounded triangular shaped floor plan of the tower has been conceptualized such that it is larger in floor area at the top floor than at its base, giving an elegant profile. This is enhanced by the cut roof shape under which there is a five-story open atrium. The tower is clad in an unconventional diagonal curtain wall that accommodates the progressively enlarging floor plate, as well as the shift of 60 degrees at the apex of the rounded triangular shaped roof.
The resulting multi-faced glass reflects the sunlight and nearby water during the day and artificial interior light during the night in various directions, giving the façade a jewel like luster. Every floor is unique, both in plate size and geometric location. In order to maximize rentable floor area there are no internal columns. The external columns twist with the building, and thus slope in two directions. To resist the resulting lateral loads, a braced steel diagrid is utilized, reflecting the triangular curtain wall system.
In order to reduce the effects of increased loading to the steel bracing in the diagrid, the installation of the bracing into the external frame was delayed by 56 days after concrete casting. During this period it was estimated that approximately 45% of the total expected creep and axial shortening would have occurred, thereby reducing the expected increase in loading to the diagrid steel bracing.
Being located in Doha where temperatures and solar gain in summer can be high, and being totally clad in a glass curtain wall, posed some challenges in terms of ensuring occupant comfort and air conditioning efficiencies. The thermal performance of the façade had a significant impact on building energy consumption. The thermal performance of the framing system also had a considerable effect on the overall performance of the façade, and the combined thermal effects of the frame and glazing were accurately calculated to determine the total thermal performance of the system. Double glazing incorporating low-E glass was adopted following extensive testing. The façade work was made more complicated by the building geometry, where every triangular panel is different.
Subscribe below to receive periodic updates from CTBUH on the latest Tall Building and Urban news and CTBUH initiatives, including our monthly newsletter. Fields with a red asterisk (*) next to them are required.
View our privacy policy