M30 Madrid Living Wall – A Landmark in Urban Greening

Introduction

The M30 Madrid Living Wall, commissioned by Madrid City Council, stands as a pioneering example of urban greening at an unprecedented scale. In collaboration with Jardinería Diego and living wall experts Terapia Urbana, this installation is now recognised as the largest outdoor living wall in mainland Europe. Spanning several hundred meters along the M30 ring road, this green wall not only enhances the visual landscape but also plays a crucial role in improving the city's air quality and biodiversity.This ambitious project showcases the potential of living walls to transform urban environments while addressing critical environmental challenges like particulate matter (PM10), NOx and CO2 reduction.

Design Vision and Objectives

The M30 Madrid Living Wall was designed with three primary goals:

Air Quality Improvement: 23 plant species were meticulously selected to enhance the wall's ability to reduce harmful particulate matter (PM10) and CO2. Scientific studies and resources, including RHS references, guided species selection to ensure maximum impact on air quality and biodiversity.
Dynamic Visual Design: The design reflects the fluid motion and light patterns found on high-traffic roads. Inspired by the escape lights of passing vehicles and wind whirlwinds, the living wall's design is visually dynamic and impactful from both pedestrian and vehicular perspectives.
Sustainable Innovation: A key feature of the design was to create a modular, efficient installation process within a strict three-month timeframe. This required an approach that allowed easy access for ongoing maintenance, including designing sections of the living wall as "doors" that can open for inspection of the supporting structure.

Key Features

1. Modular Design for Efficient Installation: With a tight deadline of three months, the installation team designed the project for efficiency. Living wall modules were pre-assembled in the factory and delivered on-site, where they were mounted to the supporting structure before planting. This streamlined approach reduced installation time while maintaining the integrity of the design.

2. Technical Flexibility for Maintenance: Due to the requirements of the M30 maintenance team, sections of the living wall were designed to function as access points. These "door" features allow for annual inspections of the supporting wall without disrupting the plants or irrigation system.

3. Advanced Irrigation System: The project incorporates a cutting-edge SCADA and PLC-controlled irrigation system designed for large-scale installations. This system allows for real-time monitoring of key factors such as soil moisture, nutrient levels, temperature, and water quality. Remote access and alerts ensure that the living wall performs optimally, even in the challenging climate conditions of the M30 ring road.

4. Minimal Plant Replacement: Thanks to the robust design and careful plant selection, the plant replacement rate has been remarkably low, with only 600 plants (0.005%) replaced out of approximately 120,000. This demonstrates the resilience and efficiency of the Fytotextile System.

Sustainability and Biodiversity Impact

The living wall plays a significant role in improving Madrid's air quality, acting as a natural filter for harmful gases like NOx and CO. Plants were tested in a specialised air chamber to assess their pollution-fixing capacity, ensuring their effectiveness in the urban environment. Data is currently being collected to quantify the environmental impact of the wall in terms of pollution reduction and air quality improvement. Furthermore, the integration of 23 plant species enhances local biodiversity, providing habitats for pollinators and other urban wildlife. The living wall’s ability to adapt to the seasonal climate conditions of Madrid ensures that the ecosystem remains dynamic throughout the year.

Irrigation and Monitoring

The SCADA system not only controls irrigation but also provides detailed analytics on the performance of the living wall. Data such as soil moisture levels, electrical conductivity, and pH are continuously monitored to optimise plant health. The system alerts the maintenance team to issues such as low soil moisture or water supply problems, allowing for rapid intervention. In addition, the system tracks environmental factors like wind, sunlight, and temperature, which are especially relevant in high-traffic areas where climate conditions can be extreme. The advanced technology ensures that the living wall remains healthy and vibrant, even under challenging conditions.

Project Scale and Recognition

The M30 Madrid Living Wall represents the first phase of a larger green infrastructure initiative aimed at improving air quality around the M30 major roadways. As the largest outdoor living wall in mainland Europe, the project has set a new benchmark in sustainable urban design. A specialised team conducts regular inspections and seasonal treatments to ensure optimal plant health and performance. Due to the low plant replacement rate, seasonal maintenance, including pruning and treatments, can be completed within one week, ensuring minimal disruption. The long-term commitment to this living wall reflects Madrid City Council’s dedication to enhancing urban sustainability.

Conclusion: A Model for Future Urban Greening Projects

The M30 Madrid Living Wall is more than just a striking visual feature—it is a powerful example of how green infrastructure can address urban challenges like air pollution and biodiversity loss. Through the expertise of Jardinería Diego and Terapia Urbana, and the innovative use of technology, this project not only beautifies the urban landscape but also delivers measurable environmental benefits. As cities across the world look for sustainable solutions, the M30 living wall stands as an inspiring model for integrating green infrastructure into urban planning.