Balancing Biodiversity Net Gain and BS5837

01.07.2024 3 min read

Balancing the Biodiversity Net Gain Objective and BS5837 Guidance Through Development

The balance between conserving and enhancing the natural environment and residential and commercial development needs presents a pressing challenge in the current landscape of urban and suburban development. The UK Government has set out its vision within the Environment Improvement Plan (Defra, 2023) to help the natural world including species targets and actions to address the urgent need to reverse the trend of biodiversity decline. This challenge needs to be addressed alongside sustainable growth and development. At the junction of this issue lie two crucial frameworks: the Biodiversity Net Gain (BNG) Objective and BS5837:2012 – Trees in Relation to Design Demolition and Construction – Recommendations. Understanding their relationship is fundamental to fostering harmonious development practices that prioritise both ecological gain and the urban tree and forest stock.

Biodiversity Net Gain requirements represent a step-change in environmental policy, mandating that new developments enhance biodiversity beyond pre-existing levels by having a measurably positive impact (a ‘net gain’) of at least 10% compared with pre-development conditions. This approach aims to reverse the trend of biodiversity decline and promote the retention and enhancement of the natural world. By quantifying a site’s biodiversity baseline and subsequent changes post-development, developers are compelled to recognise the value of existing habitats and look for opportunities to enhance them including through the incorporation of green infrastructure, habitat enhancement and habitat creation into their projects. The overarching goal is to ensure that development goes beyond minimising harm to biodiversity but instead actively contributes to its enhancement, thereby fostering ecological resilience alongside urban expansion.

Alongside this BS5837:2012 guidance provides a comprehensive framework for assessing trees before, during and after the development process. The guidance outlines methodologies for surveying, evaluating, and protecting trees on development sites, aiming to minimise adverse impacts on existing trees and hedgerows while facilitating sustainable development. By considering factors such as visual arboricultural amenities, tree health, rooting volumes, and mitigation measures, BS5837:2012 guidance seeks to strike a harmonious balance between development needs and the preservation of trees and urban green space.

At first glance, the relationship between BNG requirements and BS5837:2012 guidance may seem complementary, as both frameworks advocate for environmental stewardship within the development sector. However, navigating their relationship presents complexities and potential conflicts that require careful consideration.

One challenge arises from the varying scopes and objectives of the two frameworks. While BNG requirements focus on enhancing overall biodiversity, BS5837:2012 guidance primarily addresses the preservation of trees and hedgerows for their visual amenity and contribution to the urban setting. The retention of existing trees that may be of low arboricultural value in terms of their visual amenity, structural security or health may be scored high when evaluating a site’s Biodiversity baseline.

Furthermore, practical constraints such as site-specific conditions, land-use constraints, and stakeholder preferences can complicate the implementation of both frameworks concurrently. Developers may encounter difficulties when attempting to reconcile BNG requirements with the constraints imposed by existing vegetation assessed under BS5837 guidance. Balancing BNG and BS5837:2012 requires integrated approaches that consider the broader ecological context while safeguarding visual amenities, good urban design and public safety.

Moreover, the success of integrating BNG requirements and BS5837:2012 guidance hinges on robust monitoring, enforcement, and adaptive management mechanisms. The relationship between BNG requirements and BS5837:2012 recommendations requires a balance between conservation and development requirements in the built environment. While BNG and BS5837:2012 offer distinct perspectives and objectives, the combination of both presents opportunities that promote sustainable development whilst safeguarding biodiversity, public amenities and public safety. Specialist advice to gain a balanced approach can foster harmonious development practices that preserve ecological value and enhance the resilience of urban ecosystems and the visual amenity trees provide for future generations.

With the draft iteration of the new BS5837:2012 guidance due next month, it’s worth dropping us a line to keep in the loop with potential changes.
If you would like to know more, please contact one of the team.

Key Contacts

Duncan Smith Associate Director
Stuart Wilson Divisional Director - Ecology