Robotic System for Vertical Greenery Maintenance

Automation & Robotics for Construction

Challenge Statement Owner

WOHA focuses on researching and innovating integrated architectural and urban solutions to tackle the problems of the 21st century, such as climate change, population growth and rapidly increasing urbanisation. They are known for their distinct approach to biophilic design and integrated landscaping. The practice applies their systems thinking approach to architecture and urbanism in their building design as well as their regenerative masterplans.

GWS Living Art, founded in 2017 and originating from Chop Ching Hin Pte Ltd established in 1987, promotes sustainable living and green urban environments. Their mission is to advance nature-based solutions for livable, healthy communities. They aim to be a leader in sustainable urban nature-based solutions, focusing on decarbonising the world and creating thriving, eco-friendly cities.

Background

“Planning for greenery in Singapore has always been important to provide a quality living environment, and as a strategy to strengthen our City in a Garden identity.” (Urban Redevelopment Authority, 2017) Since 2009, URA has been encouraging the incorporation of greenery into developments via the LUSH programme. However, this comes with long-term maintenance challenges for clients and contractors, potentially disincentivising adoption.

Under URA's LUSH 3.0, vertical greenery and/or extensive green roofs will now qualify as Landscape Replacement Areas. While this may incentivise the integration of more vertical greenery and extensive green roofs in developments, they also come with added maintenance costs and risks.

Contractors face shortages of skilled workers willing to take on physically demanding tasks such as climbing to prune, replace, or inspect plants on tall facades. These activities often involve high risks, including falls, exposure to weather, and the handling of tools and chemicals in precarious positions.

Current approaches rely heavily on manual work, with workers scaling facades or using gondolas, scaffolding, or boom lifts. While these methods allow access, they remain slow, manpower-intensive, and unsafe, and they drive up long-term operational costs for building owners.

WOHA sees an opportunity to develop robotic systems that can perform inspection, pruning, and replacement of plants in vertical greenery installations. Such solutions would reduce the reliance on manual labour, improve safety outcomes, and help contractors and developers sustain more ambitious landscape designs over time.

The Challenge

How might we develop robotic systems that can safely and efficiently inspect, prune, and maintain vertical greenery on tall building facades, reducing manpower needs and improving safety outcomes?

Requirements

Functional Requirements

Perform key maintenance tasks, including inspection, pruning, replacement, and treatment of plants on vertical facades
Operate safely on tall and complex facades, including those with wire-mesh structures where plants are tightly entwined
Minimise manpower requirements while ensuring safety (Note: The speed of operation is less critical than safety and reliability)
Enable close-up inspection for plant health assessment, with potential for spraying or treatment as needed
Operate in variable site conditions (e.g., heat, humidity, wind, or rain)

Technical Requirements

Core Requirements:

Autonomous or semi-autonomous operation, with safe remote-control override when needed
High degree of movement flexibility (e.g., multi-DOF arms) to manoeuvre in complex planting patterns and avoid obstacles
Ability to support close-up diagnosis, including high-resolution imaging or touch-based sensing
Compatibility with existing facade structures and landscape systems
Built-in safety features compliant with Ministry of Manpower (MOM) and Building and Construction Authority (BCA) regulations for facade operations

Additional Preferences:

Modular design that allows for integration of inspection, pruning and replacement functions in one system
Adaptability to different facade types and plant species
Potential integration with digital models or BIM to support task planning
Scalability of system size (e.g., smaller modules for lower facades, larger units for tall buildings, etc.)

‍Expected Outcomes

Significant reduction in manpower required for facade maintenance, helping address skilled labour shortages
Improved worker safety through reduced exposure to high-risk maintenance tasks
More consistent and higher-quality plant care, reducing long-term maintenance costs
Increased feasibility of ambitious vertical greenery designs, enabling more sustainable and biophilic urban spaces

Deployment Environment and Constraints

The solution must function across diverse facade environments, ranging from low-rise residential projects to tall commercial towers. Sites may include wire-mesh facades, green walls, or planter-based systems with varying plant species and densities. The operation must account for Singapore’s tropical climate – high heat, humidity, rain, and wind – and be robust against dust and environmental wear. The system should be practical for contractors to deploy with minimal specialist training.

Proof-of-concept (POC)/Pilot Support

WOHA will facilitate pilots in partnership with clients and GWS Living Art, providing access to selected live building projects with significant vertical greenery components. GWS Living Art will test the system in real-world conditions, offering structured feedback on safety, ease of use, and effectiveness in reducing manpower.

WOHA will provide:

Access to project sites for pilot deployment
Coordination with GWS Living Art for testing and validation
Architectural and operational insights into facade design and maintenance challenges
Support in defining success metrics related to safety, labour savings, and plant health outcomes

‍Commercialisation and Scaling

Once validated, the solution would be commercialised through contractors who directly manage landscape maintenance. Different business models may be explored, including outright purchase, leasing, or service-based arrangements, depending on contractor needs.

WOHA anticipates strong demand in Singapore, where the Urban Redevelopment Authority’s Landscape Replacement Area (LRA) requirement drives developers to incorporate greenery into roofs and facades. This regulation ensures a sustained and growing market for solutions that can reduce maintenance risks and costs while enabling more ambitious architectural designs. Beyond Singapore, the solution could be scaled to dense tropical cities seeking sustainable, biophilic approaches to urban living.