CCTV Headquarters Case Study: Loop, Diagrid and Cantilever (OMA)

The CCTV Headquarters in Beijing is the head office and production centre of China Central Television, designed by OMA (Rem Koolhaas and Ole Scheeren) with Arup as engineers, won in competition in 2002 and completed in 2012. Instead of one tall tower, it is a loop: two towers lean towards each other and are joined at the bottom by a nine-storey Base and at the top by an Overhang that cantilevers 75 m. This case study explains the concept, the braced tube that holds it up and how the towers were joined in the air.

CCTV Headquarters: the facts

Architect: OMA. Partners Rem Koolhaas, Ole Scheeren and David Gianotten; project manager Dongmei Yao. ECADI (East China Architectural Design and Research Institute) was the local design institute and architect of record.

Engineers: Arup for structure, building services, geotechnics, fire and security. Main contractor: China State Construction Engineering Corporation (CSCEC).

Client: China Central Television (CCTV).

Location: the Central Business District of Beijing, China.

Years: competition won August 2002; groundbreaking 22 September 2004; structure completed May 2008; officially completed 16 May 2012.

Type: television headquarters: offices, studios, news, broadcasting and production.

Size: 234 m tall; 54 storeys above ground and 3 below; about 473,000 m² of floor area (sources differ, see below).

Status: in use as CCTV's headquarters. Not a UNESCO site.

Where to see the real drawings. The ArchDaily project page carries OMA's plans, sections, elevations and diagrams, and the OMA project page has the official credits. Arup's three Arup Journal articles, free to download, are the main source below. Our guide on how to do an architecture case study shows how to turn sources like these into sheets.

The brief and the client

CCTV, then running 13 channels and planning many more, wanted "the entire television-making process" housed in one location in Beijing's new Central Business District (Arup Journal 2/2005, pp. 3 to 9).

The brief required one site, not one building, and assumed each department would sit in its own adjoining building. OMA put almost everything into one. Arup's services engineers write that CCTV then "completely rewrote their original brief" to fit the winning concept (Arup Journal 3/2005, pp. 22 to 29). OMA allied with ECADI, since a local design institute is a legal requirement in China; Arup led engineering to the extended preliminary design, and ECADI produced the construction documents.

Site and context

OMA's 2003 text places the site in the north of the new Central Business District, close to where Chang'an Avenue meets the Third Ring Road (OMA, project PDF from Content, 2003). The 187,000 m² development holds the headquarters, the Television Cultural Centre (TVCC) with a hotel and theatre, a service building for the main plant, and a media park.

OMA called the TVCC a "fuzzy" counterpart to the rigour of CCTV: a hospitality building. A fire badly damaged the TVCC in February 2009; Architectural Record reported that the CCTV tower was not damaged (Architectural Record, Aleksandr Bierig).

CCTV Headquarters design concept: a loop, not a tower

Koolhaas had argued against the conventional skyscraper in his 2003 book Content, which has a chapter titled "Kill the Skyscraper". OMA's answer for CCTV was to bend the tower back to the ground. Its project text describes "a truly three-dimensional experience, culminating in a 75-metre cantilever" (OMA).

The loop has a working reason too. OMA wanted to break down the "ghettoes" that form in a compartmentalised process like television, and make producers, technicians and administrators mix in one connected loop of activities (Arup Journal 2/2005). In Content, OMA adds that visitors would be admitted to "the loop", a dedicated path through the secure building with views towards the CBD and the Forbidden City.

Plan and zoning: four volumes

Arup describes the building as four parts that act as one continuous tube:

The Base: nine storeys with a three-storey basement. It holds the large studios and production spaces.
Two Towers: each slopes at 6° in two directions. Studios in the towers are double height, which set the two-storey structural module described below.
The Overhang: nine to 13 storeys, "suspended 36 storeys in the air". OMA's 2008 press text put the cantilever at 75 m and its underside at about 162 m above the ground, with a public viewing deck and media museum on its lowest floor (Dezeen, August 2008).

Schematic axonometric of the CCTV Headquarters: an L-shaped Base on the ground, two towers leaning towards each other from opposite corners, and an L-shaped Overhang joining their tops, with a dashed line tracing the public visitor loop through all four parts and notes on storeys, the 6 degree lean and the 75 m cantilever — Base, two leaning towers and the Overhang form one closed loop; the dashed line is the visitor route OMA described in 2003. Diagram: MOA

In OMA's 2003 description, one tower is for broadcasting and the other for services, research and education, and they "join at the top to create a cantilevered penthouse for the management". Studios range from 2,000 m² down to under 100 m², from the lowest basement up to the 50th floor (Arup Journal 3/2005).

How big is it? The numbers disagree

Floor area: 450,000 m² in Arup's 2005 design article; 473,000 m² in its 2008 article, ArchDaily and Guinness World Records; 316,000 m² "tower footprint only" on the CTBUH Skyscraper Center.
Whole development: 550,000 m² (Arup 2005), 599,000 m² (Arup 2008) or about 600,000 m² (OMA, 2008).
Height and storeys: 234 m in every source we opened; 54 storeys above ground and 3 below (CTBUH).

Quote whichever area you use with its source and year.

CCTV Headquarters structure: the diagrid tube

Early in design, Arup decided the only way to build the form was to make the whole facade structural: an external "continuous tube" braced on every side. A tube of this size can bridge in bending and torsion between the towers, carry the lean down to the Base, and resist earthquakes and wind. In Content, OMA put it plainly: the triangulated surface of the loop "takes all the horizontal loads on the building".

Two-part structural diagram: on the left, a section through one leaning tower showing the braced tube on its faces, vertical cores stepped inside it, a two-storey transfer truss at mid-height, the Overhang with a two-storey transfer deck, and a piled raft; on the right, three facade panels showing a grid of columns and beams, then uniform diagonals, then a tuned pattern with braces doubled near the bottom and removed elsewhere — The facade tube does the structural work; the bracing was made denser or lighter where the analysis said it should be. Diagram: MOA

How the diagrid was designed

Behind the irregular pattern is a regular one: perimeter columns of steel or steel-reinforced concrete (SRC), edge beams and diagonal braces on a two-storey module that matches the double-height studios. Arup analysed a uniform pattern, then sorted the braces into three groups: add braces ("doubling"), keep them, or remove them ("halving"). Each change moved forces elsewhere, so the loop was repeated many times with OMA (Arup Journal 2/2005). The facade therefore shows the forces: the pattern is tighter where loads are higher (Arup, CCTV project page).

Cores, transfers and joints

Cores stay vertical, stepped to stay inside the sloping footprint. Sloping cores were ruled out because of the lifts.
Transfer trusses two storeys deep at about mid-height pick up internal columns that cannot run straight. They are pinned to the cores so they do not pull seismic forces into them.
Butterfly plates replace the column flanges at each node and connect braces and beams. Their shape was smoothed by analysis to avoid the stress concentrations behind weld fractures in the 1994 Northridge earthquake.

Seismic design and approval

At 234 m the building was within the Chinese code's 260 m limit for steel tube structures in Beijing, but its geometry did not comply, so an expert panel of 12 engineers and academics reviewed it. Arup used performance-based design: no damage in a 50-year earthquake, repairable damage in a 475-year one, and no collapse in a 2,500-year one. The panel also asked for physical tests, including a shaking-table model of the whole building at the China Academy of Building Research (CABR), with copper standing in for steel; Arup reports that the tests agreed closely with the analysis (Arup Journal 2/2008, pp. 40 to 51).

How the cantilever was built and joined

The order of construction changes the final forces: load added before the towers are joined is carried by each tower as a cantilever, and load added after is shared through the Overhang. So Arup's tender specification set weight audits, movement monitoring, presetting, and upper and lower limits on "locked-in" stress. Tenderers proposed a 162 m temporary tower, lifting the lower Overhang from the ground, or cantilevering from each tower; CSCEC won in April 2005 with the last.

Four schematic elevations of the construction sequence: the two towers built separately and preset upwards, the Overhang cantilevered out in two halves with a gap, the halves linked with pinned elements on the morning of 8 December 2007, and the completed loop with corner columns under the Overhang added last — The order of construction decided the final forces, so Arup wrote it into the tender documents. Diagram: MOA

The steps, from the Arup Journal 2/2008 account:

Preset. The Overhang corner was predicted to drop about 300 mm under dead weight, so the structure was preset upwards and backwards: columns on one side of each tower were made longer, to shorten to the right geometry under load.
Cantilever. From August 2007, the Overhang was built out piece by piece from each tower over five months, about 160 m up. Its corner nodes have up to 13 members and weigh about 33 tonnes each, so they were trial-assembled at the yard first.
Connect. With the towers moving about ±10 mm relative to each other each day, seven link elements were pinned within a few minutes at 9.00 am on 8 December 2007, at about 0°C, then welded over 48 hours. Arup's project page says 8 am after five days of monitoring; the journal says 9.00 am after one week.
Complete. Corner columns and braces under the Overhang were installed last, so dead load went through neighbouring members and they kept their capacity for wind and earthquakes. Steelwork topped out on 27 March 2008.

Materials and construction

Steel. From 13 February 2006, 41,882 steel elements weighing 125,000 tonnes were erected over 26 months. Column plates were up to 110 mm thick, and all the steel came from China. Arup notes there are no "typical floors": none of the 121 perimeter columns in either tower is vertical.

Foundations. Each tower stands on a piled raft with up to 370 bored piles, typically 33 m long and up to 1.2 m across. Each 7 m thick raft took up to 39,000 m³ of concrete in one pour of up to 54 hours. The 2005 design article gave piles of about 52 m and a raft up to 7.5 m; the 2008 figures describe what was built. Almost all reinforcement was joined with couplers rather than lapped (for how laps and couplers work in Indian practice, see our guide to TMT steel bars).

Facade. According to the facade consultant Front, the envelope is a blast-resistant unitised curtain wall fixed to the steel diagrid, and all the glass carries a 50% silver frit for a matte look from outside (Front). Large diagonal facade elements mirror the braces behind them.

The CCTV Headquarters in Beijing seen from the street on a clear day: two glass towers lean towards each other and are joined at the top by a cantilevered bridge, with a dark diagonal grid across the facade that is denser near the lower corners and more open higher up — CCTV Headquarters by OMA, Beijing, 2015: the diagonal grid on the facade follows the bracing behind it, tighter where forces are higher. Photo: Morio, CC BY-SA 4.0, via Wikimedia Commons

Light, climate and services

Arup's services article explains the choices (Arup Journal 3/2005):

Air. CCTV preferred variable air volume (VAV) systems. Arup's Beijing climate analysis split the year's operating hours into heating (16%), free cooling (27%), partial free cooling (43%) and minimum outside air (14%), so outside air could do much of the cooling. Chilled water pipes and drains were kept out of ceilings to protect broadcast equipment from leaks.
Plant. Instead of more than 150 floor-by-floor air plants in prime perimeter space, nine main plantrooms each serve 10 to 20 floors through risers in the core.
Health. Because of city pollution, CCTV asked for particulate and carbon filters on all air plant.
Energy. No boilers: district heating and city steam. A 64 MW peak cooling load is met by chillers plus an ice store charged with cheaper night-time electricity.

Reception

Arup's engineers record that the public and media called the design "Wei Fang", the dangerous building. Locals later nicknamed it "big pants", and Dezeen notes criticism of the overhang when the design was revealed (Dezeen, Amy Peacock, 18 January 2025).

Critics were split. Nicolai Ouroussoff of The New York Times called it "the greatest work of architecture built in this century" in July 2011 (as quoted by Dezeen). In November 2013, the Council on Tall Buildings and Urban Habitat named it Best Tall Building Worldwide, which Koolhaas found ironic given his campaign against skyscrapers (Dezeen, Marcus Fairs, 8 November 2013). In 2014 he defended it as "a very serious building" (Dezeen, Dan Howarth, 26 November 2014).

On cost, Arup's 2005 estimate for the whole development was about 5 billion RMB (US$600 million); Guinness World Records gives €850 million for the building. The scopes and dates differ, so treat neither as a final cost.

What designers in India can take from it

These are our reading, not lessons the architects stated.

Let the structure draw the facade. On an Indian project with an exposed frame, ask the structural engineer for a force diagram early and set the facade rhythm from it, instead of hiding uneven structure behind uniform cladding.
Write the sequence into the tender. For any large cantilever, transfer or long-span roof, the order of work changes the final stresses. Where Indian practice leaves this to the site, put propping, de-propping and pour sequence in the drawings, with limits the contractor must meet.
Start seismic review early. Arup met the expert panel informally three times before the formal review. In India's higher seismic zones, an irregular form needs the engineer and the approving authority involved before the design is fixed.
Count free-cooling hours before buying plant. Before sizing air conditioning for an office in Delhi, Pune or Bengaluru, check how many hours outside air could do the job. For a thesis built on this kind of analysis, see our B.Arch thesis topics by typology.

Visiting the CCTV Headquarters

The building is a working, secure broadcast headquarters. OMA planned a visitor loop and a viewing deck, but we found no official CCTV page on public visits, tours or tickets, so do not plan a trip around getting inside. The exterior is easy to see from the surrounding streets of the Central Business District.

FAQ

When was the CCTV Headquarters built?

OMA and Arup won the competition in August 2002. Groundbreaking was on 22 September 2004, the two towers were joined on 8 December 2007, the structure was completed in May 2008, and Guinness World Records gives the official completion as 16 May 2012.

Who designed the CCTV Headquarters?

OMA, with partners Rem Koolhaas, Ole Scheeren and David Gianotten. Arup did the structural, services, geotechnical, fire and security engineering, ECADI was the local design institute, and CSCEC was the main contractor.

How tall is the CCTV building and how many floors does it have?

It is 234 m tall, with 54 storeys above ground and 3 below, according to the CTBUH Skyscraper Center. The Overhang is 9 to 13 storeys deep and starts 36 storeys up.

How is the load carried in the CCTV Headquarters?

By a braced steel tube on the outside of the building: columns, edge beams and diagonal braces on every face form one continuous tube that carries the horizontal loads and bridges between the towers. Vertical cores and transfer trusses carry floors inside, and each tower sits on a piled raft about 7 m thick.

What materials is the CCTV Headquarters made of?

Structural steel and steel-reinforced concrete columns, composite concrete floors, about 125,000 tonnes of steel in all, and a glass curtain wall with a silver frit fixed to the steel diagrid.

See how architects in India document their own buildings: explore projects by MOA members.

Sources

OMA: CCTV Headquarters project page, with the project PDF from Content (2003) (accessed 3 Nov 2026)
Arup: China Central Television Headquarters (accessed 3 Nov 2026)
The Arup Journal 2/2005, Carroll, C. et al.: CCTV Headquarters, Beijing, China: Structural engineering design and approvals, pp. 3 to 9 (PDF) (accessed 3 Nov 2026)
The Arup Journal 3/2005, Green, D. et al.: CCTV Headquarters, Beijing, China: Services engineering design, pp. 22 to 29 (PDF) (accessed 3 Nov 2026)
The Arup Journal 2/2008, Carroll, C. et al.: CCTV Headquarters, Beijing, China: Building the structure, pp. 40 to 51 (PDF) (accessed 3 Nov 2026)
CTBUH Skyscraper Center: CCTV Headquarters (accessed 3 Nov 2026)
Guinness World Records: Largest television building (accessed 3 Nov 2026)
ArchDaily: CCTV Headquarters / OMA, 21 May 2012 (accessed 3 Nov 2026)
Front: CCTV China Central Television Headquarters (accessed 3 Nov 2026)
Dezeen: China Central Television Headquarters by OMA, August 2008 (accessed 3 Nov 2026)
Dezeen, Marcus Fairs: Rem "Kill the skyscraper" Koolhaas wins tall building award, 8 November 2013 (accessed 3 Nov 2026)
Dezeen, Dan Howarth: "Chinese architecture will benefit" from CCTV building, says Rem Koolhaas, 26 November 2014 (accessed 3 Nov 2026)
Dezeen, Amy Peacock: OMA's CCTV Headquarters, 18 January 2025 (accessed 3 Nov 2026)
Architectural Record, Aleksandr Bierig: The OMA-designed TVCC goes up in flames, February 2009 (accessed 3 Nov 2026)
Wikimedia Commons: Copyright rules by territory: China (freedom of panorama) (accessed 3 Nov 2026)