Transforming Rooftops: Milton Keynes’ Green Roof Revolution

As urban areas grapple with the pressing challenges of climate change, Milton Keynes has emerged as a trailblazer, spearheading a remarkable green roof movement. This visionary initiative, known as the Green Roof Project, is a testament to the city’s commitment to sustainability, biodiversity, and urban resilience.

A Pioneering Vision for Sustainable Rooftops

Milton Keynes has set an ambitious goal: to become carbon neutral by 2030 and carbon negative by 2050. The Green Roof Project is a crucial component of this strategy, transforming ordinary rooftops into vibrant green spaces that not only enhance the urban landscape but also deliver tangible environmental and social benefits.

The Birth of a Rooftop Oasis

The journey began at Saxon Court, a council building in the heart of Milton Keynes. Here, an innovative green roof showcase garden was established, serving as a living laboratory for exploring the potential of green infrastructure in urban settings.

Harnessing the Power of Modular Green Roofs

At the core of this project lies a groundbreaking modular green roof system called M-Tray®, developed by Wallbarn, a leading company in the green roof industry; which was donated by Wallbarn to the YMCA.

This innovative solution has played a crucial role in the project’s flexibility and adaptability, particularly during the relocation from Saxon Court to the YMCA building.

Modular Design for Easy Installation

The M-Tray® system comprises interlocking crates that are pre-grown with a diverse array of hardy, drought-tolerant plants, including sedum and wildflower species. This modular design allows for a straightforward and efficient installation process, making it an ideal choice for both large-scale commercial projects and smaller residential applications.

Unparalleled Accessibility

One of the standout features of the M-Tray® system is its accessibility. Unlike traditional roll-out green roof systems, the modular trays can be easily lifted and removed, allowing for seamless maintenance and membrane inspections. This flexibility was particularly beneficial during the project’s relocation, as the individual trays could be carefully transported and reinstalled at the new YMCA site.

Customisable and Adaptable

The M-Tray® system’s modular design also offers a high degree of customisation, enabling the project team to tailor the green roof to the unique requirements of the YMCA building. Whether it’s accommodating sloped surfaces, incorporating additional features like beehives, or adapting the plant selection to suit the site’s microclimate, the M-Tray® system provides the necessary versatility. Crucially, because every tray module is an individual unit, different planting schemes can be installed across an area of green roof without roots from one section migrating over to another and risking dominating the whole green roof space.

A Seamless Transition to the YMCA

In a remarkable feat, the entire green roof space at Saxon Court was successfully relocated to the rooftop of the YMCA Milton Keynes building. This transition was made possible thanks to the modular nature of the M-Tray® system, which allowed for easy disassembly, transportation, and reassembly of the green roof components. Unfortunately, most of the rollout parts of the original green roof could not be easily removed so had to be disposed of during the relocation process.

A Living Classroom for Green Infrastructure

The Green Roof Project at the YMCA Milton Keynes serves as more than just an urban oasis; it is a living classroom for educating the public and training the next generation of green infrastructure professionals. In collaboration with Bridgman & Bridgman, a leading green roof installer, and the YMCA, the project offers a mentoring and training scheme for young people from diverse backgrounds, including those with special educational needs.

A bee hive has been introduced onto the green roof and M-Tray® is providing the bees with plenty of food, who in turn are producing the most delicious honey. The beekeeper also provides education and training for the residents of the YMCA building.

Nurturing Green Roof Technicians of the Future

Through hands-on experience, participants in the program learn the intricacies of installing and maintaining various green roof types. They cultivate their own vegetables, tend to the beehives, and utilise the rooftop space for conferences, leisure and recreation. This immersive approach not only fosters practical skills but also instils a deep appreciation for the environmental and well-being benefits of green roofs.

The view from this, one of the taller buildings in Milton Keynes, across the rest of the fairly flat landscape across the city, demonstrates the scope there is to retro-green existing flat roofs city-wide.

Inspiring a Green Roof Revolution

With an estimated potential for retrofitting six full-size football pitches worth of rooftops in Central Milton Keynes, the Green Roof Project at the YMCA serves as a beacon of inspiration. By showcasing the transformative power of green roofs, the initiative aims to persuade other local buildings to embrace this sustainable solution, igniting a green roof revolution across the city.

Unveiling the Benefits of Green Roofs

Green roofs offer a multitude of advantages that extend far beyond their aesthetic appeal. They play a crucial role in mitigating the urban heat island effect, reducing flash flooding, improving air quality, and providing insulation for buildings, thereby reducing energy consumption. Moreover, these verdant oases create habitats for local wildlife, fostering biodiversity within the urban landscape.

A Sanctuary for Well-being

In the wake of the COVID-19 pandemic, the importance of access to green spaces within urban areas has become increasingly evident. Green roofs offer a sanctuary for well-being, providing residents with a tranquil escape and opportunities for recreation and relaxation amidst the hustle and bustle of city life.

Combating Urban Flooding with Green Roofs

One of the critical advantages of green roofs is their ability to mitigate urban flooding. During heavy rainfalls or flash storms, these vegetative systems act as a temporary storage solution, absorbing and retaining up to 60% of rainwater during the initial deluge and also slowing down the time it takes for the rainwater to pass through the system and into the drainage infrastructure, thereby reducing the risk of localised flooding.

Nurturing Biodiversity in the Sky

Green roofs are not merely aesthetic enhancements; they are thriving ecosystems that support a diverse array of plant and animal life. The carefully curated vegetation on the M-Tray® system, comprising sedum species and wildflowers, provides a haven for pollinators and other urban wildlife, contributing to the preservation of biodiversity within the city.

A Sustainable Investment for the Future

While the initial installation of a green roof may require a more significant upfront investment, the long-term benefits make it a financially prudent choice. Green roofs extend the lifespan of roofing systems, reducing the need for frequent replacements and maintenance costs. Additionally, their insulating properties lead to substantial energy savings, further offsetting the initial investment over time.

Embracing a Circular Economy

The Green Roof Project in Milton Keynes is not only focused on transforming rooftops but also on fostering a circular economy for green roof materials. Ongoing research is underway to explore the production of locally sourced and sustainable materials, ensuring that the project’s environmental impact is minimised from start to finish.

Monitoring and Measuring Success

To quantify the benefits of the Green Roof initiative, the Green Roof Project has implemented a comprehensive monitoring system. In collaboration with a local hackathon group, an experiment has been set up to measure the thermal and water retention advantages of the green roof. The data collected is fed to a live website, providing real-time insights into the project’s performance.

A Beacon of Inspiration for Cities Worldwide

The Green Roof Project in Milton Keynes, backed enthusiastically by Milton Keynes Council and the Mayor, stands as a shining example of what can be achieved when innovation, sustainability, and community engagement converge. As cities around the world grapple with the challenges of urbanisation and climate change, this pioneering initiative serves as a beacon of inspiration, demonstrating the transformative power of green roofs and the potential for creating greener, more resilient urban environments.