Left to right: Darren Egglesden, technical engineer at Polypipe Building Services; Rosie Cheetham, marketing manager at Polypipe Civils; Roger Wolens, managing director of The Green Organisation; Dora Zielinski, environmental manager at Polypipe Building Products; Phil Henry, market development director – specification, Polypipe Group.
Polypipe has won a Green Apple Environment Award in the annual international campaign by the Green Organisation to recognise, reward and promote environmental best practice.
In the awards, Polypipe was recognised as a Green Champion for Environmental Best Practice. The award is for a group research project into ‘smart roofs’ and utilising the installation of a blue-green roof at group company Polypipe Terrain’s plant in Aylesford, Kent, to explore new, intelligent water management systems.
The award was presented on November 26 at a House of Commons event hosted by Green Organisation managing director Roger Wolens.
The Smart Roof 2.1 research project has been underway since 2017 and aims to determine the hydrological, thermal and biodiverse functioning of blue-green roof systems in the urban environment.
One goal is to harvest and store as much rainwater for capillary plant irrigation as possible and only use potable water in the case of extreme or prolonged droughts. The greening outcome is that the system has a higher urban cooling capacity, reduces rainwater discharge run off rates to sewers and enables a wider species selection due to improved water availability.
Polypipe’s deep understanding of the water management challenges cities face – along with those of providing sustainable soft urban landscaping – meant the decision to install a blue-green roof when re-roofing its Aylesford plant was an easy one, especially as it also wanted to demonstrate the viability of retrofit green infrastructure.
Not only did the blue-green roof encourage biodiversity and prove a valued leisure space for employees; the intelligent water management system optimised greening, increased water usage efficiency and reduced waste, and managed extreme weather events.
The system comprised a drainage sub-base replacement with sedum top layer and an isolated instrumentation cell to automatically monitor and manage water supply to ensure optimum soil moisture, temperature and salinity conditions, allowing the green roof to flourish. The control and monitoring systems are operated remotely online via a smartphone, tablet, or PC.
In brief, capillary cones draw stored rainwater upwards to irrigate the green roof, while sensors within the cells monitor available water levels. If a pre-determined ‘low set-point’ is reached, the system operates a solenoid valve to add water from a rainwater recovery tank until the desirable level is reached. During high-rainfall events, excess water in the wet cell spills into the raft. When the tank reaches capacity, this water overflows to the drain.
The results of this smart management of water collection were demonstrable, positive and obvious and included: higher diversity in both plant and insect species; reduced average annual water shortages for sedum-dominated vegetation; increased evaporation reducing run off and waste water discharge to ground systems and increased building cooling capacity.
A second research project based around the Polypipe blue-green roof will consider the use of stored water for business usage, such as WCs; cooling solar panels and thus improving outputs; and its insulatory effect in winter.