PERMEABLE PAVING AND TREES IN SYNERGY
Helping to address climate change , street tree planting and retention of existing trees in developments – with provision for long-term maintenance – are now embedded in planning policy . Concrete block permeable paving offers an important opportunity to help satisfy these requirements simply , integrated with SuDS and contemporary urban design , as Interpave explains .
The 2021 ‘ National Planning Policy Framework ’ ( NPPF ) for England lays out what local planning authorities ( LPAs ) will require , when setting local policies and also considering planning applications for all developments . The NPPF states that : ‘ Planning policies and decisions should ensure that new streets are tree-lined and that opportunities are taken to incorporate trees elsewhere in developments ’.
Maintenance Requirement However , measures need to be put in place to nurture and allow trees to mature , generally for decades enabling them to actually deliver their real potential – including net carbon storage , urban cooling through shading and evapotranspiration , biodiversity and public wellbeing . So , the NPPF also requires that : ‘ appropriate measures are in place to secure the long-term maintenance of newly-planted trees , and that existing trees are retained wherever possible ’.
Local planning authorities will now incorporate long-term tree maintenance measures in their planning consents and a straightforward spatial solution , such as permeable paving , offers a holistic multifunctional solution .
Urban trees and paving have traditionally been seen as in conflict . But this is not the case with concrete block permeable paving , a key sustainable drainage ( SuDS ) technique to reduce flood risk and make cities more liveable .
Concrete block permeable paving ( CBPP ), offers unique opportunities to collect , attenuate and treat rainwater runoff , removing pollutants for a gradual supply of clean water irrigating green infrastructure . Essentially , this technology shares the same impressive performance as conventional modular concrete paving products , being slip resistant , durable , strong and sustainable .
The difference with permeable paving is enlarged joints , filled with a permeable aggregate , and the materials used below the blocks , which are specifically selected to accommodate water without clogging . Concrete block permeable paving is unlike – and not to be confused with – permeable materials , which behave very differently .
Irrigation and Gas Exchange Unlike conventional impermeable hard landscape materials , CBPP allows the same pattern of run-off transfer to the ground as natural vegetation , enabling water to reach tree and shrub roots , despite providing an attractive hard surface above . In addition to irrigation directly from rain , with CBPP there is scope for water storage and rainwater capture away from trees and their umbrella canopies , for gradual conveyance laterally to trees – essential during the summer .
In addition , CBPP enables air to reach roots and poisonous CO2 to escape . The favourable environment created for tree roots avoids pavement surface disruption and facilitates natural growth into lower levels for stability and longevity . CBPP can be used within newbuild , or regeneration schemes with new tree planting and also for ‘ rescuing ’ mature trees . Concrete block permeable paving can be used
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