Sustainability

Buildings and developments can adversely affect climate change and also be adversely affected themselves by those changes. Consequently it is important to look at ways of mitigating against these issues at the outset and planning for the nature of predicted climate changes throughout the life of the building, not just the current climate.

The Buildings Research Establishment has concluded that Green roofs are altogether better able to cope with the forecast climate changes, namely higher wind speeds, heavier rainfall and longer hotter summers.

The Green Roofs Naturally Green Roof system has been functioning for more than 25 years, it is tried and tested and it is self sustaining and will continue to be so, throughout “the life of the building”. Installing a Greenroofs Naturally Green roof will protect the waterproof membrane, preventing exposure to UV light and extremes of temperature, extending the overall life of the roof itself. The basis of the Green Roofs Naturally system is the recycled foam mat. Produced under modern efficient and economic production processes, the Nutrifoam Mat is embedded with slow release nutrients, to ensure there is minimal impact on the quality of the water runoff. The Extensive soil substrate, sourced locally, consists of recycled brick (non-contaminated). The simplicity of the system also makes it infinitely adaptable and practical for installation being non-labour intensive. The cost is competitive and our supply chain and partnership working are all designed to ensure the quality and value of this system is the imperative to ensure the whole of life costs are kept to a minimum.

The Nutrifoam mat is unique in its multi- functional purpose, providing both part of the growing medium and the drainage system. This minimises the manufacturing required to produce the Green Roofs Naturally system and the resource consumption.

The system itself is extremely lightweight. When the extensive green roof, with a substrate depth of 4cm, is fully saturated, it weighs 56 kilos per m². Water attenuation is a key element of the sustainable benefit of the Green Roofs Naturally system. From a hydrological point of view the roof functions differently from a hard roof. Rainwater is retained and evapotranspiration takes place from the vegetation, while the rainwater runs off directly from the hard roof. There is a clear seasonal effect for the runoff reduction, runoff does not occur until the mat and the substrate are fully saturated and is also dependant upon the precipitation period and volume. The Nutrifoam mat alone will hold 25 litres of water m², effectively acting as a sponge to control and slow the storm water runoff, which means that local urban flooding and combined sewer overflows can be lessened. Throughout the year due to the high level of water storage and transpiration, the runoff is less than 50% of the precipitation. This has important implications for SUDS and as such Green roofs are now considered a SUDS technique.

The thermal mass of a building is important in how it responds to heat loss and gains. Lightweight systems can heat and cool faster. The Nutrifoam mat assists in reducing heat gain in summer to maintain comfortable temperatures within the building.

Assuming the roof installed is an extensive green roof, using predominantly sedum as the growing plant material, then maintenance after installation of mature sedum mats could be limited to once per annum- ideally in spring, preferably May. We would recommend this is carried out by our contractors under a maintenance agreement that supports our Guarantee of function.

The maintenance regime would include;

• Removal of debris and dead vegetation, from the roof surface, drainage outlets and guttering and washed pebbles, etc.
• Weeding and removal of grass / saplings (purely aesthetic.)
• Sowing of additional sprouts to repair patches of poor growth.
• Application of maximum 50gm² of slow release, low nitrogen fertiliser.

As awareness grows about the significance of climate change, so too will the demand for and value of, buildings which are designed with sustainable characteristics. Overall it is the simplicity of approach which is fundamental to the Green Roofs Naturally system which has been proved and tested over the last 25 years.