The Urban Greening Factor

Decoration Decoration

Green infrastructure is now a necessary planning policy requirement and cannot simply be delivered as an ‘add-on’

Policy & Legislation
Practical Planning Advice
Author Alex Yearsley
Principal Planner
Decoration Decoration

What is the Urban Greening Factor?

The Urban Greening Factor (UGF) is a planning tool that originated in Berlin some time ago and has subsequently been adopted in a number of cities in Europe, including here in London.   The requirements for ‘Urban Greening’ are set out in Policy G5 of the London Plan (2021) and seek to provide a simple way for Local Planning Authorities to score green infrastructure interventions in new developments. The policy clearly has good intentions, though it means far more thought needs to be given to green infrastructure at the start of the design and planning process for new developments.  The UGF is currently only applied to major applications, but the London Plan indicates it may eventually be applied to applications below this threshold as boroughs develop their own unique models.

Calculating Urban Green Factor for Development

The UGF enables major developments to calculate and demonstrate how urban greening has been included as a fundamental element of building design by assigning a factor score to different surface cover types, which are weighted based on their potential for rainwater infiltration.  Scores range from 1 for semi natural vegetation through to 0 for impermeable sealed surfaces. The total score is calculated by adding up the different scores for the different surface cover types within a development.  Until local boroughs develop their own models, the London Plan recommends a target score of 0.4 for developments that are predominately residential, and a target score of 0.3 for predominately commercial development (excluding B2 and B8 uses).  It is important to note that existing green infrastructure on site that is retained can also be counted towards the overall score.

Delivering Green Infrastructure

Here at Bell Cornwell LLP, we can advise clients on how to meet the UGF requirement through a variety of interventions.  Green interventions, such as green roofs/walls and rain gardens can be incorporated into residential and commercial development projects and effectively contribute to urban greening targets. Unlike “grey infrastructure”, which is inherently limited to single functions such as drainage or transport, “green infrastructure” is distinguished by its potential to address several problems simultaneously, such as improved health, climate change adaption and biodiversity conservation. Conventional grey infrastructure is still necessary but can often be reinforced by natural solutions such as new trees, hedges, grass, flower rich perennial planting or through the retention of existing green cover on sites.

The Impact of the Urban Greening Factor

The UGF scheme in London will undoubtedly prompt a significant increase in green installations like living walls and green roofs making the most of every building surface. UGF is also likely to push developers to use less harsh ground surfaces, which will reduce flooding and the urban heat island effect.

The impact of UGF will depend on how each borough adapts it, but its decades-long history in cities around the world shows that there is a lot of potential to improve the places in which we live and work.

We support the UGF’s aim of creating a landscape led planning approach but we are also keenly aware of the possible cost and management implications for our clients.  Properly considered green infrastructure cannot simply be delivered as an ‘add-on’ and it is now a necessary planning policy requirement that requires careful consideration.

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