WITH PRESSURES FROM GOVERNMENTAL AND OTHER ORGANISATIONS TO IMPROVE THE DESIGN OF THE SPACES BETWEEN BUILDINGS THAT HELP DEFINE OUR URBAN ENVIRONMENT, WE ALSO NEED TO CONSIDER THE SUSTAINABILITY CREDENTIALS OF PAVING MATERIALS.
When specifying paving, designers need to keep in mind a wide range of requirements – identified in guidance such as the Manual for Streets and increasingly recognised in planning policies - including:
But how can specifiers exercise their responsibilities to select sustainable paving materials? Here, the BRE Green Guide to Specification offers guidance. It rates various building elements from ‘A+’ for best environmental performance to ‘E’ for the worst and it looks specifically at ‘Landscaping’, comprising of external paving and boundary protection. Three different paving scenarios cover: Pedestrian Areas; Lightly Trafficked Areas, such as car parking; and Heavily Trafficked Areas. The same three scenarios with identical results are applied across the six different building types considered by the Green Guide. The summary environmental ratings for a range of precast concrete paving specifications – covering blocks, flags and ‘grass concrete’ units - are generally ‘A’ or ‘A+’ across all three scenarios.
INDEPENDENT ENDORSEMENT
These ratings provide independent endorsement of the low environmental impact of precast concrete paving, particularly in comparison with imported materials, and reflect the ongoing environmental investments and improvements made by Interpave manufacturer members, as well as by the cement industry generally. Although not considered in the Green Guide, precast concrete kerbs will have similar environmental characteristics to concrete flags, whereas alternative kerbing materials such as plastic remain an unknown quantity. Localised material sourcing and product supply are also key to sustainable construction, and equivalent paving products shipped into the country bear a substantial CO2 emission load over those locally supplied. Some imported stone paving products are also included in the Green Guide – generally with much poorer environmental ratings than their precast concrete equivalents and half with the worst ‘E’ rating.
SUSTAINABILITY IN USE
Green Guide ratings also form an important part of BREEAM 2008 (the Building Research Establishment’s Environmental Assessment Method) as well as the Code for Sustainable Homes (CSH). Taking the Educational Building version of BREEAM as an example, one credit is available where at least 80% of the combined area of external hard landscaping and boundary protection specifications achieve a Green Guide A or A+ rating - generally the case with precast concrete paving. But BREEAM and CSH also consider other criteria, such as use of concrete block permeable paving and other Sustainable Drainage System (SUDS) techniques.
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