Jeddah Tower vs. Burj Khalifa: The 1,000m Megaproject Construction Timeline

Height comparisons look simple until you ask which height. The Council on Tall Buildings and Urban Habitat (CTBUH) — the industry’s reference body for skyscraper rankings — recognizes four separate categories: height to architectural top (including spires, the category used above), height to the highest occupied floor, height to the roof, and height to the tip (including antennas). A building can rank differently in each one. The clearest historical example is the 1996-1998 dispute between Chicago’s Sears Tower and Kuala Lumpur’s Petronas Towers: Sears was taller to its roof and highest occupied floor, but Petronas’s spires pushed its architectural-top height higher, and CTBUH awarded it the “world’s tallest” title on that basis — a decision that was argued over for years. When this article compares buildings, it uses architectural height consistently, and calls out the other categories only where they change the picture.

The “world’s tallest building” title has changed hands slowly, and each holder solved a different engineering problem. The Empire State Building (1931, New York, 381 meters to roof, 443 meters with its later-added antenna) proved that a steel-framed skyscraper could be built fast — it went up in about 14 months during the Depression — and held the record for 40 years, longer than any other building since. The Willis Tower (opened 1973 as Sears Tower, Chicago, 442 meters) introduced the “bundled tube” structural system, nine framed tubes bundled together, which let architects go taller without a proportionally heavier frame — a structural idea that shaped nearly every supertall building afterward.

The Petronas Towers (1998, Kuala Lumpur, 452 meters to spire) took the record to Asia for the first time and settled nothing about how “tallest” should be measured, as the Sears dispute above shows. Taipei 101 (2004, Taipei, 508 meters) was the first building to seriously address earthquake risk at extreme height, using an 800-tonne steel pendulum tuned mass damper visible through the building’s own facade. Then came Burj Khalifa (2010, Dubai, 828 meters) — a jump of 320 meters over the previous record, the largest single leap in the history of the “world’s tallest” title, built using a structural system (below) that made every subsequent supertall project possible. Merdeka 118 (2024, Kuala Lumpur, 678.9 meters) is the most recent entrant: it didn’t challenge Burj Khalifa, but at second-tallest in the world it confirmed the supertall race didn’t end when Burj Khalifa topped out. Jeddah Tower is the next attempt at the title itself — and the first serious attempt at a full kilometer.

Construction began in January 2004 with excavation for the foundation — piling driven deep into Dubai’s soft coastal ground to anchor a tower that would eventually weigh several hundred thousand tonnes. By June 2006 the tower had passed 50 storeys, and the pace of the record itself became a running story: in February 2007 Burj Khalifa passed Taipei 101 to become the tallest structure under construction anywhere in the world; by July 2007 it had passed Toronto’s CN Tower to become the tallest freestanding structure ever built; by April 2008 it had passed the KVLY-TV mast in North Dakota to become the tallest man-made structure of any kind. On January 17, 2009, the final spire section was installed, fixing the tower’s height at 828 meters. Exterior cladding was finished by October 2009, and the building opened to the public on January 4, 2010 — almost exactly six years after excavation began.

What made that possible structurally was engineer Bill Baker’s buttressed core system, developed at SOM: a central hexagonal core braced by three wings arranged in a Y-shaped plan, each wing buttressing the others against wind load. As the tower rises, each wing sets back in a spiraling pattern, which does two things at once — it reduces the building’s cross-section as loads decrease with height, and it continuously changes the shape wind sees as it moves up the tower, disrupting the vortex shedding that causes tall buildings to sway. Concrete was pumped to a then-unprecedented height of 606 meters during construction, requiring a specially formulated high-strength, low-viscosity mix that could still be pumped that far without segregating. Getting people and materials up a structure that size required 57 elevators, including double-deck cars serving sky lobbies at intervals up the tower rather than a single shaft running the full height — the same “elevator relay” approach later supertall buildings, including Jeddah Tower, have had to adopt.

Even before Burj Khalifa opened, Saudi developers were discussing a tower that would surpass it. The project took shape as the centerpiece of Jeddah Economic City, a large mixed-use development on Jeddah’s northern coastline, developed by the Jeddah Economic Company (JEC) — a consortium majority-owned by Kingdom Holding Company, the investment firm chaired by Saudi Prince Alwaleed bin Talal. Early announcements described an aspiration to build past one kilometer, but the ambition and the construction schedule were two different things: a public announcement of intent is not the same as a funded, engineered, permitted project, and it took several more years for the tower to move from concept to groundbreaking.

Jeddah Tower is designed by Adrian Smith + Gordon Gill Architecture (AS+GG), a Chicago firm Adrian Smith founded in 2006 after leaving Skidmore, Owings & Merrill (SOM), where he had led the design of Burj Khalifa. This is a distinction worth being precise about: Burj Khalifa and Jeddah Tower were not designed by “the same team” in any simple sense — they were designed by the same lead architect, at two different firms, working with different structural engineers and nearly a decade apart. Gordon Gill is lead architect on the Jeddah project alongside Smith. The design draws visibly on Burj Khalifa’s wind-engineering lessons — a tapering, setback silhouette — while using a different plan geometry suited to Jeddah Tower’s own height target.

Groundbreaking took place in April 2013. Early construction focused on the piece of the project least visible from outside: the foundation. This was not a formality — a tower designed to exceed a kilometer needed a foundation system that had never been built at this scale in this kind of ground, and getting it wrong was not a recoverable mistake once the tower above it existed.

Jeddah’s coastal site sits on sandy soil contaminated with coral, which does not bear heavy loads reliably on its own. German specialist contractor Bauer drilled 270 bored concrete piles, each up to 110 meters deep and 1.8 meters in diameter, reaching down to more competent rock. These piles connect to a five-meter-thick reinforced concrete raft that distributes the tower’s enormous vertical load — ultimately several hundred thousand tonnes of concrete and steel — evenly across the pile field, rather than concentrating it at a few points. Groundwater near a coastal site adds corrosion risk to buried steel and concrete over the tower’s intended service life, which is one reason foundation design for a project like this takes years, not months, to finalize before the first pile is even drilled.

Construction was suspended amid Saudi Arabia’s late-2017 anti-corruption campaign, which detained dozens of senior royals and businessmen, including two figures directly tied to this project: Kingdom Holding chairman Prince Alwaleed bin Talal, a lead financial backer of the tower through JEC, and Bakr bin Laden, chairman of Saudi Binladin Group, the main contractor. Bin Laden was reportedly released roughly three years later, in 2021. The detentions landed on top of an already-weakened contractor — Saudi Binladin Group had been under financial strain since the 2014–2016 oil-price downturn slowed government construction payments across the kingdom. The combination of leadership uncertainty at the developer and financial distress at the contractor is what actually stopped work in January 2018, not a single cause; reporting on the halt generally cites both factors together rather than isolating one.

What followed was not a quick fix. Between 2019 and 2023, the project sat in an extended limbo: financing had to be reworked, the contractor relationship had to be re-established, and neither JEC nor Kingdom Holding published a public restart timeline during those years. It took until October 2024 for a new construction contract to be signed — again with Saudi Binladin Group, the same contractor as before the halt — before full-scale work resumed in January 2025.

The restart is well documented, unlike the halt: Kingdom Holding’s October 2024 contract with Saudi Binladin Group was announced publicly and covered by international press including CNN. Full-scale construction resumed in January 2025 with the tower at 63 floors — essentially the same point it had reached in 2018, meaning seven years produced almost no additional height, only a great deal of institutional repair work behind the scenes. Since then, floor-by-floor progress has been documented repeatedly through 2026: 80 floors by January, 100 by April, 107 by late July. This is a real, ongoing, independently photographed construction restart, not a re-announcement of an old promise.

As of the most recent confirmed reporting (late July 2026), the tower’s core has reached its 107th floor, at approximately 430 meters — roughly 43% of its planned final height. This is a construction-progress figure reported by architecture and construction press tracking the build, not a figure independently surveyed by AiTimeline; treat it as current-best-available rather than laser-measured fact. It is important not to confuse this current construction height with the tower’s planned final height of more than 1,000 meters — the two numbers describe different things, and conflating them is the single most common error in coverage of this project.

The tower’s design target has consistently been described as “more than 1,000 meters” since the project was first proposed, and a specific figure of 1,008 meters has circulated widely in press coverage for years. What has never been published is a final, developer-confirmed architectural height — JEC has not issued a definitive number the way, for example, Emaar published Burj Khalifa’s height at opening. Given that the tower is currently under 45% built, and that supertall projects have historically adjusted final specifications during construction, the most accurate statement available in mid-2026 is: the design intent is to exceed one kilometer, construction is currently proceeding toward that goal, and the exact final figure will not be certain until the tower tops out.

Wind speed rises with altitude, and at supertall heights the concern isn’t just steady wind pressure but vortex shedding: as wind flows around a uniform tower, it peels off in alternating swirling eddies on either side, and if that shedding frequency lines up with the building’s natural sway frequency, the motion can amplify rather than damp out. Engineers fight this primarily with shape rather than brute strength — tapering the tower, setting back its profile at intervals, and rounding or notching corners all break up the wind’s path so it can’t organize into a steady shedding pattern. Jeddah Tower’s design uses exactly this strategy: a three-lobed, tapering plan intended to disrupt vortex formation, following the same wind-engineering logic Adrian Smith used at Burj Khalifa. None of this eliminates wind’s effect on the building — occupants at extreme height will always feel some motion in strong wind — it reduces that motion to a level that’s structurally safe and comfortable rather than removing it entirely.

Jeddah Tower uses a three-lobed, Y-shaped footprint, described by the architects as inspired by the folded fronds of young desert plant growth — a single form at the base that separates into distinct wings as it rises. Functionally, the shape does two jobs: the triangular, tapering wings reduce wind loading through the vortex-disruption mechanism above, and the three-petal layout suits residential and hotel floor plates better than a simple rectangular or circular tower would. Horizontal notches cut into the facade create shadow lines that shield open terraces from direct desert sun. Plans for the tower have long included a sky terrace near the top of the structure, intended as one of the highest observation points ever built into a supertall tower — its exact final floor and public-access details have not been confirmed and will depend on how construction proceeds over the next several years.

Project reporting has described Jeddah Tower’s vertical transportation plan as roughly 56 elevators, with express cars designed to run at speeds around 12 meters per second — figures that come from construction-industry coverage of the project rather than a formal specification sheet AiTimeline has independently verified, so they should be read as reported rather than certified. What’s structurally certain, because it’s true of every building this tall, is that a single elevator shaft cannot efficiently serve a full kilometer: express elevators will need to run to intermediate sky lobbies, where passengers transfer to local cars for the remaining distance, the same relay system Burj Khalifa uses. At extreme speed and height, cabin pressurization also becomes a real engineering concern, similar in principle to aircraft cabin pressurization, to keep rapid altitude change comfortable for passengers.

Supertall buildings are designed around the assumption that a full, single-direction evacuation down one stairwell is not a realistic primary strategy in every emergency scenario. Instead, the standard approach — used at Burj Khalifa and expected at Jeddah Tower — combines fire-resistant compartmentation (so a fire stays contained to its zone rather than spreading vertically), pressurized and protected stairwells, designated refuge floors at intervals where occupants can shelter and await instructions, dedicated fire-service elevators, and independent emergency power and smoke-control systems. AiTimeline has not seen a published, official evacuation-time figure for Jeddah Tower and will not estimate one; any number claiming to state exactly how long a full evacuation would take should be treated skeptically absent a cited engineering source.

Western Saudi Arabia sits in a region of low-to-moderate seismic activity compared with the Pacific Rim, but supertall structural design still accounts for regional seismic conditions as a matter of course, building in redundancy so that no single structural element is solely responsible for the tower’s stability. The building’s structural system and deep-pile foundation are designed to withstand the seismic conditions specified for the region under the applicable Saudi building code. That is a meaningfully different, and more accurate, claim than saying the building is “earthquake-proof” — no supertall structure anywhere claims that, and none should.

Jeddah’s Red Sea coastal climate brings a different set of stresses than Dubai’s: high year-round humidity on top of extreme heat, intense direct solar exposure, and wind-blown dust and sand that accelerate wear on both exterior cladding and mechanical systems. The facade’s notched geometry (above) is a direct response to solar exposure, shading terraces rather than relying purely on glass coatings. Humidity combined with heat also raises corrosion risk for embedded steel reinforcement over a multi-decade service life, which is one reason concrete cover depth and reinforcement protection are treated as long-term durability decisions during design, not just short-term construction specifications.

As of August 2026, Burj Khalifa remains the world’s tallest completed building at 828 meters, a title it has held for more than 15 years. Jeddah Tower is not the world’s tallest building yet — it is the world’s tallest building under construction, at roughly 430 meters and still less than half finished. It will not take the completed-building title unless and until it tops out at a height exceeding 828 meters and formally opens; nothing about its current construction status changes Burj Khalifa’s standing today.

Kuala Lumpur’s Merdeka 118 reached structural completion in late 2023 and formally opened in January 2024, reaching 678.9 meters — making it the world’s second-tallest building, well ahead of third-place Shanghai Tower at 632 meters. Merdeka 118 never set out to beat Burj Khalifa; it matters here because it shows the supertall race stayed active in the 14 years after Burj Khalifa opened, even without anyone challenging the top spot. Jeddah Tower, if completed at its planned height, would not just take the top spot from Burj Khalifa — it would open a gap to second place larger than the gap that currently exists between first and second.

No other project currently under active construction is targeting kilometer-scale height. Several kilometer-plus concepts have been proposed or discussed publicly over the past two decades — including earlier Gulf-region proposals that were never approved or funded — but a rendering or announcement is not the same as an approved, financed, under-construction project, and this article won’t list speculative concepts as if they were real timelines. The honest state of the field in 2026 is that Jeddah Tower is the only project actively attempting to build past one kilometer, and whether anything follows it likely depends on whether it succeeds.

If completed, Jeddah Tower could plausibly draw tourism, generate long-term hospitality and office employment, and give Jeddah a global architectural identity distinct from Riyadh’s or Dubai’s — but these are potential and expected outcomes, not measured ones, since the tower isn’t finished and hasn’t opened. Prior supertall projects, including Burj Khalifa, did generate substantial tourism and real-estate attention for their host cities, which is the basis for these expectations rather than a guarantee specific to this project.

Jeddah Tower is one of several large Saudi infrastructure projects moving forward under Vision 2030, the kingdom’s economic diversification program launched in 2016. It’s worth being precise about the relationship: Vision 2030 is the broader policy context the tower exists within, not the reason the tower was originally proposed — the project predates Vision 2030 by several years. What Vision 2030 has plausibly affected is the political and financial environment around the 2024 restart, at a time when the kingdom has prioritized visible, internationally covered construction projects as part of its broader economic messaging.

It’s tempting to treat this story as purely a race to a number — will the core reach 1,000 meters or not. But reaching that height is arguably the easier part, in the sense that it’s a known, solvable engineering problem: taller towers than this have been modeled, and the physics of wind, weight, and foundations at this scale is understood, even if it hasn’t been built before. The harder problem is everything that happens after the core tops out. A tower this tall has to be structurally safe across decades of wind loading and thermal cycling, comfortable for people living and working near its top in strong wind, maintainable by crews who can actually reach every mechanical system and piece of facade, economically viable as hotel rooms, offices and apartments that people actually want to occupy at that height, and operationally efficient to run for the decades after opening. Burj Khalifa answered all of those questions at 828 meters. Jeddah Tower is the first real attempt to answer them past 1,000.