WOHA Architecture: Tropical High-Rise Design Explained

Few practices have shaped the image of contemporary Singapore as strongly as WOHA. Its towers wrapped in creepers, hotels with gardens stacked through their height and public housing with villages in the sky have become shorthand for tropical high-rise design worldwide. Understanding WOHA architecture is a good way to understand how architects in hot, wet, dense cities are rethinking the tall building.

This article introduces the practice, explains its key ideas, walks through its most important Singapore projects, and considers what its approach asks of structural and building services engineers.

The practice

WOHA was founded in Singapore in 1994 by Wong Mun Summ and Richard Hassell, who had met while working at Kerry Hill Architects. The name combines the first two letters of each founder’s surname. The practice began with houses and small projects in Singapore and the region, and by the 2000s was designing high-rise housing, transport infrastructure, schools and hotels.

Its international profile rose quickly. In 2007, 1 Moulmein Rise, a slender residential tower in Singapore, received the Aga Khan Award for Architecture. The Met in Bangkok, completed in 2009, won the International Highrise Award in 2010 and the RIBA Lubetkin Prize in 2011. These early towers established the themes that would define the practice’s later work.

The ideas behind WOHA architecture

Climate first

WOHA’s buildings start from the tropical climate rather than from imported models of the sealed, air-conditioned tower. Shade, cross-ventilation, rain protection and the use of outdoor space are treated as primary design drivers. At 1 Moulmein Rise, for example, the practice developed a “monsoon window” that allows ventilation even during heavy rain. The principles are those described in our guide to tropical architecture, applied consistently at high-rise scale.

Landscape as infrastructure

Greenery in WOHA’s work is not applied decoration. Sky gardens, planted facades and landscaped roofs are integrated into the section and structure, intended to shade, cool, support biodiversity and give occupants usable outdoor space at height. The practice argues that buildings should give back more landscape than their sites originally contained.

Stacked public space

Rather than a single ground floor with a sealed shaft above, WOHA’s towers are often organised as a stack of “grounds”, each with its own communal garden, terrace or public room. This is a response to density: if land is scarce, the city’s public realm has to continue upwards.

Measuring generosity

WOHA has developed its own rating metrics to make these qualities measurable, including Green Plot Ratio, Community Plot Ratio, a Civic Generosity Index, an Ecosystem Contribution Index and measures of self-sufficiency in energy, water and food. The practice set out its wider thinking in Garden City Mega City (2016), a book produced with Patrick Bingham-Hall and launched at the Venice Architecture Biennale.

Key Singapore projects

Bras Basah and Stadium MRT stations (2008): transport infrastructure treated as civic architecture; Bras Basah won World Transport Building of the Year at the 2009 World Architecture Festival.
School of the Arts (2010): a stacked, naturally ventilated school building in the city’s arts and civic district, named World Learning Building of the Year in 2010.
PARKROYAL on Pickering (2013): a hotel conceived as a garden, with a contoured podium and cantilevered sky gardens. See our article on PARKROYAL COLLECTION Pickering.
SkyVille@Dawson (2015): HDB public housing organised into stacked sky villages of 80 homes. See our article on SkyVille Dawson.
Oasia Hotel Downtown (2016): a red-mesh tower covered in creepers, named Best Tall Building Worldwide by the CTBUH in 2018. See our article on Oasia Hotel Downtown.
Kampung Admiralty (completed 2017): an integrated development combining apartments for seniors, a medical centre, childcare and eldercare, shops, food outlets and a rooftop park and farm, named World Building of the Year at the 2018 World Architecture Festival.
Pan Pacific Orchard (2023): a hotel on Claymore Road organised around stacked open-air terraces, later recognised with a Prix Versailles award.

The practice also designed the masterplan for Punggol Digital District and several of its buildings, and the Singapore Pavilion at Expo 2020 Dubai.

What WOHA’s buildings ask of engineers

From a structural engineer’s perspective, WOHA’s architecture is demanding in specific, recurring ways. Sky gardens place heavy, wet landscape loads at height, often on cantilevers or above long spans. Multi-storey voids cut through towers interrupt the floor diaphragms that normally carry wind loads to the core, so alternative load paths must be designed. Open, porous towers can experience different wind pressures and local flow effects from sealed ones, which affects both structural design and occupant comfort, and is typically studied through wind engineering.

The facades bring their own challenges. Planted screens, meshes and deep shading elements must resist wind as plants mature, accommodate building movement and remain safely maintainable for decades. Irrigation, drainage and waterproofing become building services that the structure must support. Projects of this kind succeed when landscape architects, structural engineers and services engineers are involved from the concept stage, a pattern visible across WOHA’s work and discussed in our guide to the sky garden.

Influence and debate

WOHA’s influence on Singapore is visible well beyond its own buildings. The city’s landscaping policies, which encourage developments to replace lost greenery with sky terraces and planted areas, have found some of their most persuasive built examples in the practice’s projects, and many other architects have adopted similar approaches. Internationally, its work has helped make the case that the tall building in the tropics should look and behave differently from its temperate counterparts.

There is also healthy debate. Critics question whether extensive greenery is always maintained as intended, how much energy it truly saves, and whether the costs of landscape at height are justified. These are fair questions, and they are best answered with long-term performance data rather than photographs taken on opening day. What is not in doubt is that WOHA has shifted the conversation about what a tropical tower can be.

Frequently asked questions

Who founded WOHA?

WOHA was founded in Singapore in 1994 by Wong Mun Summ and Richard Hassell, who met while working at Kerry Hill Architects. The name combines the first two letters of each founder’s surname.

What are WOHA’s most famous buildings?

Its best-known Singapore buildings include PARKROYAL on Pickering, Oasia Hotel Downtown, Kampung Admiralty, SkyVille@Dawson, the School of the Arts, Pan Pacific Orchard and the Bras Basah and Stadium MRT stations. Abroad, The Met in Bangkok is among its most celebrated works.

What is distinctive about WOHA architecture?

WOHA designs from the tropical climate, using shade, natural ventilation and integrated greenery, and stacks communal gardens and public spaces through the height of its buildings. It also measures qualities such as greenery and community space through its own design metrics.

What awards has WOHA won?

Major awards include the Aga Khan Award for Architecture in 2007 for 1 Moulmein Rise, the RIBA Lubetkin Prize in 2011 for The Met, the CTBUH Best Tall Building Worldwide in 2018 for Oasia Hotel Downtown, and World Building of the Year at the 2018 World Architecture Festival for Kampung Admiralty.

Working on a building with sky gardens, deep voids or planted facades and need structural input early? Talk to our consultancy or get in touch.