Guoco Tower: How Singapore's Tallest Building Was Built

Guoco Tower, at Tanjong Pagar, has been Singapore’s tallest building since its completion in 2016. At 290 metres it stands slightly above the long-standing 280-metre ceiling that shaped the Central Business District skyline for three decades, and it achieved that height through a special exemption. Most people know it as an office address, a hotel or a station exit. It is better understood as a carefully engineered vertical city stacked on top of a working railway.

This article explains who designed and engineered Guoco Tower, how its mixed uses are arranged, the structural ideas that hold it together, and what made its basement one of the more difficult parts of the job.

A vertical city at Tanjong Pagar

The development was launched as Tanjong Pagar Centre by GuocoLand, which also has its Singapore headquarters in the building. It was designed by Skidmore, Owings & Merrill (SOM) with Architects 61 as the local architect. Arup provided structural engineering, facade engineering and sustainability design, and Samsung C&T was the main contractor. Construction began in 2013, the tower was topped out in January 2016, and the office and retail components received their Temporary Occupation Permit later that year.

The programme is a classic mixed-use development, pushed to an unusual height. Grade A offices occupy the lower and middle part of the tower. Above them sit the apartments of Wallich Residence, with the uppermost floors reserved for the most exclusive units. A hotel, Sofitel Singapore City Centre, occupies an adjoining block, and retail, food and beverage fill the lower levels, with a direct connection to Tanjong Pagar MRT station. The whole complex is more than 60 storeys and offers around 158,000 square metres of floor area.

The public realm: City Room and urban park

At street level SOM designed a sheltered public space called the City Room: a naturally ventilated event and gathering space under a canopy about 15 metres high. The canopy incorporates building-integrated photovoltaic cells, which filter daylight, help keep the space below cooler, and supply up to about two per cent of the development’s energy. Beside it is a landscaped urban park, part of an effort to give back meaningful ground-level space in one of the densest parts of the city.

The office and commercial components achieved BCA Green Mark Platinum and LEED Platinum ratings, while Wallich Residence received Green Mark GoldPlus. These are design and operational achievements as much as architectural ones: the facade, glazing and building services were engineered together to cut cooling load in a climate where cooling dominates energy use.

How Guoco Tower stands up

Tall towers in Singapore are rarely governed by earthquakes; they are governed by wind, by the weight of the building itself, and by the need to keep movement and sway within comfortable limits for occupants. Guoco Tower uses a reinforced concrete core as its backbone, with the floors spanning out to perimeter columns to keep office floor plates open. Our overview of tall building structural systems explains why a core-and-frame arrangement is the default choice at this height.

Changes in geometry and the core

Arup has described the building’s scale and changing geometry at several levels as the source of much of the design complexity. Where a tower steps or changes shape, inclined columns and floors generate horizontal “kick-out” forces that have to go somewhere. Arup’s solution was to embed large steel plates with shear studs in the concrete core walls, so those forces could be transferred directly into the core. This composite detail lets steel do what it is good at, carrying concentrated tension and shear, while the concrete core provides overall stiffness. Our guide to core wall structures covers how such cores are designed and built.

Stacking homes on offices

Residential and office floors want different things from a structure. Offices prefer long spans and few columns; apartments have shorter spans and different layouts, services and fire compartments. Where one sits on top of the other, the columns rarely line up perfectly. Arup designed a transfer plate and belt-wall system that ties together the residential and office portions of the tower and stabilises them. The transfer level redistributes the load of the upper floors onto the lower structure, while belt walls around the perimeter engage the outer columns and help the tower behave as one stiff unit. Our article on transfer beams explains the same principle at a smaller scale.

Building over a railway

The site is bounded by four roads, gazetted heritage shophouses and an operating MRT station. That combination makes the below-ground work some of the most sensitive on the project. Arup’s design made the three-level basement connect structurally with the MRT station and serve as a retaining wall. The team adopted a full top-down construction method for the basements, as also reported by the construction press at the time.

In top-down construction, the perimeter walls and internal plunge columns are installed first, then the ground-floor slab is cast and excavation proceeds downward beneath it, with each basement slab propping the walls as it is built. Meanwhile, the superstructure can rise above. The method limits ground movement next to sensitive neighbours, which matters a great deal beside a live railway and historic shophouses, and it can shorten the overall programme. It also demands careful sequencing and excellent coordination, because permanent structure is doing temporary work during construction.

Height, the skyline and the 280-metre limit

For decades, the tallest towers in the CBD topped out at around 280 metres, a ceiling linked to aviation height controls. Guoco Tower is the exception, allowed to reach 290 metres. The difference is modest in metres but meaningful in symbolism: it marks the southern end of the CBD with a tower clearly taller than its neighbours. Aviation height limits are now being reviewed, and a new generation of towers is planned to rise higher still, which we discuss in our article on the Singapore skyline.

Architecturally, SOM gave the tower a relatively restrained form with a strong vertical expression. It is not a flamboyant building, and that is part of its success. The design effort went into how the tower meets the ground, how its uses are organised, and how the structure resolves a complicated stack, rather than into a dramatic silhouette.

What engineers can learn from it

Guoco Tower is a useful case study for anyone involved in large mixed-use projects. It shows that the hardest structural problems in a supertall-scale building are often at transitions: between uses, between geometries, and between the new building and the infrastructure around it. Solutions such as embedded steel plates in core walls, belt walls and top-down basements are not exotic, but combining them on a constrained site beside a railway requires early coordination between architect, engineer, contractor and the authorities. That is a lesson that applies equally to far smaller projects.

Frequently asked questions

How tall is Guoco Tower?

Guoco Tower is 290 metres tall, which has made it the tallest building in Singapore since its completion in 2016. It was granted an exemption from the 280-metre height limit that had applied to the CBD’s tallest towers.

Who designed Guoco Tower?

It was designed by Skidmore, Owings & Merrill with Architects 61 as the local architect. Arup was the structural and facade engineer and sustainability consultant, and Samsung C&T was the main contractor, for developer GuocoLand.

What is inside Guoco Tower?

The development combines Grade A offices, the Wallich Residence apartments on the upper floors, the Sofitel Singapore City Centre hotel, retail and dining, a sheltered public City Room and an urban park, with a direct link to Tanjong Pagar MRT station.

Why was top-down construction used for Guoco Tower?

The basement sits beside an operating MRT station, heritage shophouses and busy roads. Building the basement top-down, with each slab propping the walls as excavation proceeded, limited ground movement and disruption and allowed the superstructure to rise at the same time.

Working on a complex mixed-use or tall building and need accountable structural advice? Talk to our consultancy or get in touch.