Turning Grey into Green
The complete urban drainage and greening solution
Grey to Green is a proven urban greening and SuDS solution developed by The Green Estate that transforms hard, impermeable surfaces into living, planted systems. Designed to manage rainfall, reduce surface water runoff, improve water quality and enhance urban environments, it delivers long-term performance for both people and nature.
Proven through over 12+ years of real-world performance
Built around an engineered substrate and planting system, Grey to Green has delivered more than 12 years of verified performance across large-scale SuDS infrastructure projects. Developed through practical research and long-term monitoring, it delivers reliable hydrological function and resilient planting in demanding urban conditions.
Technical credentials:
- Developed through research with the University of Sheffield
- Tested to BS 8616:2019
- CIRIA SuDS Manual compliant filter medium performance
- Proven hydraulic conductivity of 2.1 mm/min
- No major maintenance interventions required
- Demonstrated long-term operational performance
Grey to Green SuDS Substrate®
The engineered foundation of the Grey to Green system
At the core of the system is the Grey to Green SuDS Substrate®. This is a peat free, civil engineering-grade infiltration and planting medium made entirely from recycled and reclaimed materials. Designed to support both reliable hydrological performance and robust plant establishment, the substrate balances technical drainage requirements with the needs of long-term planting success.
Why specify Grey to Green SuDS Substrate®?
- Reduces surface water runoff
- Supports infiltration and flood resilience
- Captures pollutants and improves water quality
- Provides high aeration for healthy root development
- Supports resilient, long-term planting performance
- Resistant to clogging and compaction
- Suitable for installation in all weather conditions
- Sustainable, peat-free and manufactured from recycled materials
Designed for long-term performance
Combine with Grey to Green Gravel Surface Mulch®
For optimum performance, Grey to Green SuDS Substrate® can be combined with Grey to Green Gravel Surface Mulch® to create a durable, stable and low-maintenance SuDS system.
Benefits include:
- Reduced long-term maintenance requirements
- Improved surface stability and durability
- Reduced weed colonisation and unwanted growth
- Enhanced visual appearance and consistency
- Protection of the underlying substrate and planting system
Typical applications
Grey to Green SuDS Substrate® is suitable for:
- Rain gardens
- Bioswales
- Bioretention systems
- Detention basins
- Streetscape SuDS schemes
- Highway retrofit projects
- Public realm improvements
- Residential developments
- Commercial developments
- Climate resilience projects
Grey to Green, Sheffield – A proven model for urban SuDS
After the 2007 floods, Sheffield required a new approach to managing surface water within tight urban constraints. Working with Sheffield City Council, the Grey to Green scheme transformed a 1.6 km dual carriageway into a planted, climate‑resilient SuDS corridor.
Designed by Professor Nigel Dunnett and Zac Tudor, and installed and maintained by The Green Estate, the scheme demonstrates long‑term, real‑world performance of the integrated engineered substrate, planting system and installation method.
Performance highlights:
- 12+ years operational performance
- Verified infiltration and pollutant‑capture behaviour
- Demonstrated long‑term resistance to clogging
- Improved water quality entering the River Don
- Biodiversity uplift and enhanced public realm
- Installed and continually maintained by The Green Estate
Let’s create greener, more resilient places
Grey to Green SuDS Substrate® and the wider system can support SuDS, bioretention, urban retrofit projects and climate‑resilient public realm schemes.