Rainwater Recycling

Green BuildingsHousing & Development Board
Funding support, mentorship, testbed and deployment opporutnitiesAccess to pilot and test facilities
Construction, Water Management Tech, Green Buildings 
The Housing & Development Board (HDB) in Singapore is responsible for public housing in Singapore. HDB plays a significant role in planning and developing public housing estates, managing housing policies, and providing affordable and quality housing options to the residents of Singapore. 

As Singapore's public housing developer, HDB has a commitment to craft sustainable solutions that play a pivotal role in fortifying the various towns' capacities to effectively manage stormwater. To this end, they have centred their efforts on bolstering key facets related to water management, specifically water retention, detention, and recycling capabilities.

This multifaceted approach entails a concentrated effort to optimise the efficacy of capturing, storing and utilising rainwater, with a particular emphasis on its application during instances of extreme weather conditions. The goal is to harness the potential of rainwater as a valuable resource, thus reducing the country’s dependence on traditional sources of water supply.

Amid a changing climate, it has become increasingly critical to ensure that their infrastructure is not just resilient but also adaptive to address the mounting challenges posed by severe rainfall. Singapore experiences two distinct monsoon seasons, and we have witnessed a notable increase in the intensity of these events. For instance, October 2022 rainfall was the highest for the month of October in the past four decades. Such extreme weather events are becoming more common.

At the same time, with Singapore’s rising population, our demand for water is increasing.
How might we improve water detention and retention capacity in urban environments?

HDB is seeking groundbreaking solutions that can harness extreme weather events to become beneficial to communities and the environment. They welcome creative proposals that can boost Singapore’ rainwater detention and retention capacity, fortify our city's resilience, and steer Singapore towards a more sustainable future.

They are looking for innovations to:
  1. Manage runoff coefficients to prevent flooding and water pollution;
  2. Detain and retain rainwater during heavy rainfall; and/or
  3. Intensify rainwater recycling to effectively and safely reuse rainwater for various non-potable purposes like irrigation and toilet flushing, and thus reduce reliance on conventional water sources.


  • Scalability:  The proposed solution should be scalable and capable of implementation across multiple HDB estates through HDB's BTO projects or the Green Towns Programme.

  • Integration: The solution should seamlessly integrate with existing HDB infrastructure and systems, including the electrical grid and building management systems. It should not necessitate significant modifications to the current infrastructure.

  • Durability: The solution should be durable and have a long lifespan, at least comparable to the current building materials and systems used in HDB estates. It should be capable of withstanding Singapore's harsh tropical climate and requiring minimal maintenance over its lifespan.

  • Cost-effectiveness: The solution should be cost-effective to produce and use, offering a reasonable payback period and a low total cost of ownership. It should not substantially increase the construction or maintenance costs of HDB estates and should deliver long-term cost savings.

  • Safety and compliance: The solution must prioritise safety and comply with relevant regulations and standards, such as the Building and Construction Authority's (BCA) Green Mark certification and safety standards. It should not pose any safety risks to residents or the environment and should meet all applicable regulatory requirements.


Pilot implementation will be supported by HDB Centre of Building Research. For new buildings, collaboration with the Building Research Institute (BRI) for the design of new HDB blocks may be necessary.

Our goal is to complete the development of the proposed solution within a two-year timeframe. This time encompasses both the solution development phase and testbedding at the Centre of Building Research.

Resources and incentives

Testbed Opportunities: The HDB Master Laboratory, Centre of Building Research, will offer testbed opportunities, enabling the development team to refine the solution in a controlled environment and ensure compliance with relevant standards.

Mentorship: HDB Officers will offer mentorship to the development team, providing guidance and support throughout the process to align the proposed solution with HDB's goals and requirements.

Funding Support: Innovators can consider incorporating elements of community engagement and education on the adoption of the solutions at public spaces. You can find out more and submit your proposals to SG Eco Fund at:

Deployment Opportunities: Successful solutions may be deployed in HDB buildings or estates through HDB's BTO projects or the Green Towns Programme, allowing the development team to scale up their solution and contribute to a more sustainable future for Singapore.

Info Session 

Check out the recording from our Info Session, where HDB shared more about their challenge statement.

Market Potential / Business Opportunity

Singapore is home to 1 million HDB flats located in 24 towns and three estates across the island. These flats accommodate about 80% of Singapore's resident population. The solutions, if successful, will be deployed to flats islandwide.

Other Considerations

Your proposed solution should be cost-effective and provide a reasonable payback period, while also meeting the performance requirements and sustainability goals of HDB.

Making Your Application 

Before you make an application, you will need to register an account on our platform. You will receive a confirmation email upon registration. 

Once done, you may proceed to submit your application with your credentials. You can also save your application as a draft if need.

Applications close on Wednesday, 31 January 2024 at 11.59pm (GMT+8).