Haikou Workers’ Activity Center
Located on Hainan Island, Haikou is characterized by a hot and humid coastal climate. Designed by the Green Architecture Design & Research Institute of CADG, the newly completed Haikou Workers’ Activity Center is conceived around the concept of “Tree of Life” and organized as an “Ecological Settlement,” setting a new benchmark for climate-responsive public architecture in Haikou.
More than a civic complex integrating cultural, sports, and training programs, the project creates an urban oasis—community-oriented, climate-responsive, and low-carbon in operation.
Rooting Design in Haikou’s Local Context
The project is located in Haikou’s Jiangdong New Area, adjacent to the Guilinyang National Tropical Agriculture Park, embracing views of coastal estuary wetlands to the west. High-end residential neighborhoods lie to the north and west, while to the south are football fields. Set within a rapidly developing urban district, the project benefits from rich natural resources, convenient accessibility, and urban planning potential.
The city’s hot and humid coastal climate, marked by abundant rainfall and persistent monsoon winds, informs a climate-responsive design approach.
Climate Constraints
Haikou’s tropical climate imposes three fundamental requirements: shading, natural ventilation, and transitional spaces to buffer rainfall, heat, and humidity. In response, the architecture establishes an integrated spatial system that simultaneously provides solar protection, promotes natural airflow, shelters from rain, and moderates the hot, humid environment.
Site Ecology
Set within a coastal plain, the site is characterized by lush vegetation, an interconnected water system, and a clearly defined ecological framework. The project therefore adopts a low-intervention approach, seeking to preserve the existing ecological corridor formed by waterways, vegetation, and open ground.
Local Lifestyles
The relaxed rhythm of everyday life in Hainan—with its frequent morning and evening activities—has long shaped a reliance on shaded and naturally ventilated semi-outdoor spaces. This calls for an open spatial relationship between different programs, providing continuous settings for walking, lingering, social interaction, rest, and semi-outdoor activities.
The “Tree of Life” Above the Oasis: Supporting Community Life with Traditional Architectural Wisdom
“When shaded spaces and cool alleys take shape here, traditional wisdom truly comes to life in contemporary architecture.”
— Cui Kai, Academician of the Chinese Academy of Engineering
The concept of “Ecological Settlement” emerges from a deep understanding of Hainan’s climate, traditional architectural wisdom, and community life. Drawing on the climatic strategies of traditional Li boat-shaped houses and Haikou’s arcade buildings, particularly natural ventilation and open ground-floor spaces as key references, the architecture is envisioned as a “Tree of Life”—its massing expands upward from a smaller footprint, unfolding like a tree.
More than a formal expression, the design embodies a synthesis of community life and ecological thinking. Expansive roof overhangs provide solar shading and rain protection, forming a 2,100 m² three-dimensional circulation network. The X-shaped steel bracing anchors both the roofs and platforms, reducing ground-level columns and opening the peripheral spaces. The open ground floor and wind inlets form “breathing corridors” that improve the microclimate and provide comfortable spaces for daily activities. Internally, diverse facilities for sports, performance, training, and community activities are organically connected through a north-south ecological corridor and an east-west circulation axis, balancing functional independence and a continuous public realm.
The massing evokes the growth of a tree—from roots to branches, the architecture accommodates diverse programs while generating a layered ecological environment.
“It feels like a small city, or even a village, where diverse public activities converge.”
— Liu Heng, Director of the Green Architecture Design & Research Institute of CADG
Creating Shade: Climate-Responsive Design
In response to Haikou’s hot climate, intense solar exposure, heavy rainfall, and persistent monsoon winds, the project adopts multiple strategies to shape its massing and spatial organization.
Expansive Above, Tapered Below: Creating Shade and Shelter
Following an inverted massing logic—expansive above and tapered below—the architecture rises like a tree, transforming into a large-scale shelter from sun and rain. Horizontal eaves extend outward in successive layers to create a three-dimensional, all-weather circulation network, providing sheltered semi-outdoor space.
The open building perimeter creates opportunities for passive strategies, with natural ventilation, solar modulation, deeper overhangs, planting, and water features enhancing the microclimate.
Through a systematic approach combining semi-outdoor spatial organization, passive environmental moderation, and thermal comfort assessment, spaces that would otherwise rely on air conditioning are transformed into non-conditioned buffer zones beneath the eaves. Together, these strategies create a three-dimensional, self-shading spatial system that integrates climate responsiveness, public activities, and ecological buffering.
Open Ground Floor: Facilitating Natural Ventilation
Drawing from the climatic wisdom of Haikou’s traditional arcade buildings and vernacular boat-shaped houses, the project responds to prevailing northeast and southeast winds throughout the year through large-span ground-floor open spaces and strategically positioned wind inlets, forming a “breathing corridor” system that integrates climatic regulation with spatial connectivity. The north-south ventilation corridor measures 33 m in width and 12 m in height, while an additional 14.5 m-wide wind inlet on the southeast side channels monsoon breezes into the site. Programs are lifted, sunken, and staggered according to their spatial scale and environmental requirements, generating a porous ground level with interconnected voids that facilitate continuous airflow.
Wind simulations indicate that the main entrance street maintains an annual average wind speed of 2.3 m/s, while no significant stagnant air zones or vortices are identified within activity areas across the site during summer and transitional seasons. The elevated structure therefore forms a ventilation framework closely integrated with prevailing wind directions, functional organization, and spatial scale. Inspired by the principles of traditional “cool alleys,” these porous ventilation spaces weave through the building, creating continuous semi-outdoor spaces that promote air exchange at the ground level and improve the microclimate.
Program Stacking: Layered Platforms Linking Diverse Spaces
Functional configurations respond to the spatial requirements of different programs. Large-span spaces such as sports facilities and performance venues are partially embedded below ground, where surrounding soil provides a thermal buffer that reduces exposed surface area by 30-40% and mitigates glare. Smaller, more frequently used spaces are organized across Levels 3 to 5 around three courtyards, while shared exhibition spaces are concentrated on the south side, contributing to a more compact and coherent spatial order.
These semi-outdoor spaces and ventilation corridors also support rainwater management and vegetation growth, fostering an active interplay between architecture, climate, and ecology while creating a climate-responsive environment where public life and ecological systems coexist. The continuous platforms further connect diverse habitats and ecological systems across multiple levels, forming an interconnected three-dimensional ecological network.
From Structure to Environmental Systems: Self-Regulating Low-Carbon Architecture
A low-carbon ethos underpins the project throughout its lifecycle. Rooted in the local climate, the design establishes strong synergy among structural systems, construction logic, material selection, and environmental strategies. Carbon reduction anchors the entire design and construction process, shaping an integrated approach to low-carbon architecture.
Diagonal Bracing System: Low-Carbon Structural Strategy
The building combines a steel frame with X-shaped diagonal bracing to support multi-level overhanging canopies. The structural system itself becomes an architectural expression, minimizing the need for decorative cladding and finishes. By largely removing suspended ceilings and adopting an open, highly integrated structural framework, the project significantly reduces material use. Meanwhile, lightweight ETFE membranes, composite aluminum panels, and recycled aluminum further reduce carbon emissions throughout the building’s lifecycle.
Photovoltaic Integration: Energy Self-Sufficiency
Cadmium telluride (CdTe) thin-film photovoltaic modules are integrated directly into the roof assembly, forming approximately 10,000 m² of BIPV roofing that generates about 1.15 million kWh of electricity annually. Blue photovoltaic modules alternate with timber-toned elements, conjuring the imagery of waves meeting the beach. Following the principle of prioritizing on-site consumption and feeding surplus electricity back into the grid, the system establishes a bidirectional energy loop between the architecture and the grid. The photovoltaic system supports approximately 40% of the building’s full-load demand when all functions are operating simultaneously, enabling near-zero-energy performance under most typical operating conditions.
Energy Circulation and Self-Regulation
Centered on the synergy of “wind, light, water, greenery, and air,” the project integrates passive environmental strategies with active energy systems to establish a self-regulating low-carbon operation model.
Rainwater is harvested from roofs, platforms, waterfalls, and streams, then reused through systems such as micro-drip irrigation for vegetation. The photovoltaic system generates clean energy to support building operations, while wind flows through the porous ground level, corridors, and open interfaces to dissipate heat and promote natural ventilation, reducing reliance on mechanical cooling. Water-nourished ecological planting further enhances the microclimate, creating a positive feedback loop between carbon sequestration and energy conservation.
By integrating energy production, water circulation, and ecological regulation, the architecture moves beyond a one-way resource-consuming model, operating as a near-zero-energy ecosystem characterized by energy self-sufficiency, resource circulation, and environmental self-regulation.
The concept of an “Ecological Settlement” goes beyond technical solutions to shape everyday interactions between people, architecture, and nature. This vision is supported by an integrated system of photovoltaic generation, rainwater reuse, and vibrant semi-outdoor spaces, creating a self-regulating low-carbon environment. Like a “Tree of Life,” the project offers a new model for green architecture in Hainan’s tropical coastal context.
Meanwhile, it extends the value of green design beyond environmental performance, reimagining the possibilities of everyday community life for local citizens.
CREDITS
Design Firm: China Architecture Design & Research Group (CADG)
Design Principal: Cui Kai
Lead Architect: Liu Heng
Design Team:
Architectural Design: Yang Xi, Xu Feng, Shi Hong, Wang Xin, Wang Yueru, Wang Peng, Chen Lishuang, Yan Wei, Wang Haodong, Gu Jingyun, Huang Jianzhao, Lü Rui, Su Qi, Sun Peixu
Structural Engineering: Han Ling, Huo Wenying, et al.
Water Supply & Drainage: Cao Jian, et al.
HVAC: Xu Hongxing, et al.
Electrical & Intelligent Systems: Li Lei, et al.
Landscape Design: Liu Huan, Li Yang, et al.
Interior Design: Wei Li, Liu Rong, et al.
Green Building Consulting: Li Tianyang, et al.
