Policy OB3
Urban greening
The council will seek to enhance green infrastructure and make the borough visibly greener. The council will:
a) Require all development proposals to integrate green infrastructure and urban greening as a fundamental element of site and building design from early stage of the design process, and by incorporating measures such as high-quality landscaping (including trees), green roofs, and nature-based sustainable drainage.
b) Require major developments to:
- Submit an Urban Greening Factor (UGF) assessment in accordance with the methodology set out in the London Plan 2021.
- Achieve an UGF of a minimum of 0.4 for developments that are predominantly residential.
- Achieve an UGF of a minimum of 0.4 for developments that are predominantly commercial.
c) Ensure that any urban greening element will tackle the climate emergency and help avoid or mitigate the impacts of the proposed development on biodiversity by providing locally relevant greening that complements the site's existing wildlife value and that will achieve an overall gain in biodiversity
d) Protect existing trees and resist any loss of a tree, group of trees, area of vegetation of significant amenity, historic, cultural, and/or ecological value on, or adjacent to, a development site.
e) Make Tree Preservation Orders (TPO's) when necessary to protect specific trees, groups of trees, or woodlands, in the interests of amenity and biodiversity.
f) Require replacement trees and/or vegetation to be provided where the loss or harm to the wellbeing of significant trees and/or vegetation has been justified in the context of the proposed development.
g) Maximise the provision of gardens, garden space and soft landscaping, seeking green roof and other planting as part of new development.
h) Promote the creation and management of incidental habitats in all development to support species and contribute to overall biodiversity.
9.28 Green infrastructure includes parks, playing fields, front and rear private gardens, grassed areas, trees, allotments, hedges, green roofs and walls. Urban greening describes the incorporation of green infrastructure, and it can provide multifunctional benefits including climate change resilience, managing overheating and microclimates, reducing pollution and improving air quality, tackling surface water flooding and improving habitat enhancements as well as increasing visual amenity which provides mental and physical benefits.
9.29 The council will seek to enhance green infrastructure continuing to pursue its ambition of being a green and healthy borough and contributing to achieving net zero greenhouse gas emissions by 2030 as part of the Climate emergency and the Council's Climate Change and Ecology Strategy. To achieve this goal, the council will require all development to integrate green infrastructure and provide for urban greening. Urban greening measures should be considered at an early stage of the design process and incorporated as part of an integrated design approach. This will improve its quality and maximise its benefits.
Urban Greening Factor (UGF)
9.30 London Plan Policy G5 sets the Urban Greening Factor (UGF) requirement for major developments. The UGF model helps calculate the quality of the green infrastructure provided by new development.
9.31 The council will therefore require major developments to submit an Urban Greening Factor (UGF) assessment in accordance with the methodology set out in the London Plan (2021) and will apply a UGF score of 0.4 for residential and commercial developments. The increase from 0.3 to 0.4 of the London Plan's benchmark for developments that are predominantly commercial is based on local evidence. These target scores should be seen as minimum and therefore higher scores are encouraged.
Loss of trees
9.32 The benefits of trees and woodlands are extensive and there is a need to protect and increase these green elements in the borough. Trees and urban forests contribute to enhancing local character and amenity, and they provide areas of habitat for wildlife. Trees play also a key role in tackling climate change adaptation and mitigation by absorbing rainwater, easing pressure on drains, and improving local climates through shade and cover.
9.33 The I-Tree Canopy survey highlights that the borough has a lower-than-average canopy cover of 14%, compared to the London average of 21%. To achieve the vision for more trees in the borough, the Council is committed to increase the canopy cover from 14% to 16.5% by 2030 and 23% by 2050. The H&F Tree Strategy provides detailed guidance on tree management and diversity of tree species. The strategy aims to increase canopy cover from 14% to 16.5% by 2030 and to preserve urban forests in the borough applying the '10/20/30' rule, an international guideline that help increase urban forests diversity and resilience against pests, diseases, and other environmental stressors.
9.34 The council will seek the protection and retention of existing trees and will resist the loss of any tree, group of trees, or vegetation with significant amenity, historic, cultural, or ecological value, whether on public highway and on land adjacent to a development site which can potentially be affected by a proposed development. Development proposals should retain and protect existing trees, ensuring they can be sustained for long-term. The removal or mutilation of trees will not be acceptable without strong justification, particularly where trees are protected by a Tree Preservation Order, lie within a Conservation Area, or contribute meaningfully to local ecology and character, public amenity, or biodiversity. Pruning or reduction, in line with best practice, should be explored as an alternative to removal. New developments should also incorporate landscaping, including new tree planting, to enhance the site and support ecological and environmental quality.
Replacement planting
9.35 The council will seek replacement planting on-site of an appropriate size, number and species in an appropriate location. There will be circumstances where it may not be possible for trees, or trees providing the same amenity or biodiversity benefits. to be replaced on-site because of the footprint of proposed new buildings or insufficient space/constraints on public highway. It will always be the council's priority for any significant trees lost to be replaced within the curtilage of the development. As a working benchmark, we expect at least two new trees to be planted for every tree lost. This benchmark will be applied flexibly, on a case-by-case basis recognising that site constraints can impact on the ultimate size of trees, and we will therefore give preference to proposals where trees can be sustained into maturity. Where it is demonstrated to the Council's satisfaction that replacement planting is not feasible, we will expect equivalent benefits to those provided by existing trees and vegetation to be secured and realistic replacement and / or compensation to be provided.
9.36 A methodology such as 'i-tree' [1] should be used to inform replacement planting for large major applications (100 or more homes or 2,500sqm or more commercial floorspace). The i-tree tool can be used to quantify the value provided by individual trees taking account of benefits they provide such as air quality, carbon dioxide reduction, shading and stormwater management. We will expect applicants bringing forward large major schemes to submit an i-tree assessment (or an alternative methodology which has been agreed with the Council) as part of the planning application. The council will prioritise the use of any commuted sums for the funding tree of planting in the immediate area, for example tree planting on council owned land such as highways, parks, housing estates and nature reserves. This funding will also be required to cover maintenance costs and will be secured by a S106 agreement.
9.37 The council will require a detailed landscaping scheme or planting plan to include a management plan, to be secured by a planning condition or in a Section 106 agreement. This will ensure that all planting on site is sustainable and adequately maintained in line with standard BS8545 for a sufficient duration. The council will also expect the applicant to replace trees lost prematurely due to death or disease up to 10 years from when the landscaping plan was implemented.
9.38 Front, side, and rear gardens enhance biodiversity, the townscape, and quality of life. Parking in front gardens can add visual clutter and be detrimental to the appearance of the street scene, impact on permeable surfaces and reduce the potential for soft landscaping and tree planting which would add to the street scene. The council wishes to protect gardens from development where possible and generally discourage impermeable paving unless original and support its removal. The enhancement of front gardens will not only help improve the street environment and biodiversity but will also reduce the rate of surface water run-off and the risk of flooding.
Incidental habitats
9.39 The promotion of incidental habitats within all new developments is a vital strategy to enhance urban biodiversity and support local wildlife. Incidental habitats, such as green roofs, rain gardens, native species planting, bird and bat boxes, and other small-scale green feature play a crucial role in creating shelters, food sources, and movement corridors for a wide range of native species. These habitats contribute not only to the conservation of biodiversity but also to the resilience and ecological connectivity of urban environments.
9.40 Incorporating incidental habitats early in the design process maximise their ecological effectiveness and ensures they become an integral part of the built environment rather than an afterthought. The long-term management and monitoring of these habitats are essential to maintain their value and functionality over time, providing benefits for both wildlife and the local community. In addition to their ecological benefits, incidental habitats provide valuable co-benefits, including improved urban cooling, flood mitigation, air quality enhancement, and opportunities for environmental education and community engagement. By supporting the creation and management of incidental habitats in all development, this policy fosters healthier, greener, and more sustainable urban spaces that contribute to the borough's wider biodiversity and climate resilience goals.
[1] i-Tree Tools - Calculate the benefits of trees!