Natural environment

The value of trees within the built environment

Goal: To understand the value trees can bring to all developments and integrate them properly to enhance the scheme

^p14. Trees in all developments are important and have multiple benefits to all of us and to our natural environment. Not only do they enhance the character and appearance of an area, increasing the draw of the area to local visitors and tourists, there is clear evidence that properties on a tree lined street will have a greater financial, social, and environmental value than those without (TDAG No trees, No future, 2010).

^p15. Trees and hedgerows, individually and collectively, can make an important contribution to biodiversity and the landscape. They also absorb atmospheric pollution and have a beneficial influence on the climate. Development proposals should provide a net increase in tree canopy cover where this is possible, having regard to other considerations including site size, heritage protection, landscape character, habitat protection and compatibility (e.g. turning priority habitat grassland into a plantation woodland would not be suitable), residential amenity, and the need to make the best use of land.

^p16. The environmental benefits are significant. Trees can assist with climate control through air cooling in summer months, filtering pollutants, improving air quality, and absorbing carbon dioxide. They can also play a key role in reducing surface water flooding and provide valuable habitats and movement corridors for wildlife. The social and cultural elements of our lives can be enhanced by the presence of trees. They can form attractive features to our outdoor areas for recreation, the backdrop for relaxing and the inspiration and visual relief along our busy transport routes. It is proven that having access to trees and meaningful green spaces is vital for good mental and physical health at all ages.

^p17. The retention of appropriate mature trees within a development can add a valuable sense of maturity to a scheme. Mature trees will visually soften what can otherwise be a harsh development until new planting is established. Incorporating existing trees into public open space as a focal point in a development will achieve the most benefits, providing a community hub and a sense of connection with nature. Trees should be planted at an early stage to allow them to grow naturally, helping to soften the appearance of a development over time in a sustainable way.

Figure 4:

The positive contributions of tree planting in the built environment

Planting in a development proposal

Goal: Use planting to help a development integrate into the landscape with its own character and sense of place

^p18. New planting can have multiple uses, such as defining the character of an area, or creating soft boundaries with hedgerow planting, improving the visual appearance and provide resources for wildlife, or being part of Sustainable Drainage Systems (SuDS) and traffic calming measures, whilst providing a wider range of benefits.

^p19. It is essential that all landscaping is designed in coordination with all of the above and below ground utilities infrastructure including lighting. This will avoid conflicts that would prevent the planting from being implemented and maximise long term benefits. It is key that during the design stage, sufficient space both above and below ground is provided for the requirements of tall growing and large canopied trees to be incorporated into the layout. Such trees are essential to help mitigate the effects of climate change, provide long-term softening and integration of the development.

^p20. Trees should be planted for the long-term so that they can grow to maturity and deliver their benefits. This means that they need sufficient soil volume to grow in. To make this possible, integrated, joined-up thinking and planning is essential so that the use of space both below and above ground is properly thought through and coordinated. Avoid relying only on planting trees in private gardens where their future cannot be secured.

Tree pits hold rain water for sustainable drainage

Trees can provide a windbreak and shading in the public realm

Trees help remove carbon from the atmosphere

Clusters of trees provide natural habitats

Figure 5: Design considerations and wider benefits of planting in the built environment

Planting is your asset

^p21. Tree planting schemes should use a range of species, sizes and regular spacing corresponding to the nature and hierarchy of the street. Main streets will need to be of sufficient width to incorporate large, canopied trees set well back from buildings. Designing a site layout around green spaces allowing for the future growth potential of the planting scheme will enable the landscape to mature to its full potential and be a key feature of the development. Tree planting should be of a scale to grow above the roof line to help soften and assimilate development on the long term.

^p22. Seeing your planting scheme as an asset that can add value to a development will encourage a holistic design approach. Larger growing tree species should be used where possible as the benefits they provide are much greater, with relatively little installation cost.

^p23. Make the most of your planting by designing tree planting for dual use, such as creating or enhancing a certain landscape character to a development, as well as being a key component of a drainage system - this is a good use of resources.

Aftercare and maintenance

^p24. A key tool to ensure the successful establishment of a planting scheme is aftercare and maintenance programmes, such as a Landscape Management Plan. Seeing your planting scheme as an asset that is worth caring for with simple measures will ensure it achieves its full potential, successful establishment, and a return on your investment.

^p25. It is essential to have a budgeted management programme in place to monitor and maintain new plantings on their journey to establishment. Failure to establish new plantings prevents the delivery of their benefits.

Figure 6:

Generic principles to be addressed when designing a tree pit. Professional guidance should always be sought from a range of professionals. Structure tree pits to ensure sufficient soil volume, in a hydrated, aerated and uncompacted form. Investment required at the design stage to ensure the correct tree rooting environment is achieved during implementation and establishment stage. Increasing benefits when tree reaches maturity in a healthy state.

Make sure:

New planting including trees are designed appropriately into the layout. This should be explained in the landscaping strategy, and where applicable, complete and submit the following documents with your application:

a topographical survey;

a Tree Survey in accordance with BS 5837

an Arboricultural Impact Assessment produced in accordance with BS 5837;

an Arboricultural Method Statement, including a Tree Protection Plan in accordance with BS 5837

all landscaping is designed in coordination with all other above and below infrastructure, including utilities, visibility splays, highway layouts, drainage, etc.;
the planting scheme including tree planting scheme uses a range of species and sizes, appropriately spaced to correspond to the nature and hierarchy of the street or open space and suited to the site’s soil type. A mix of species is required with no more than 20% of any genus and no more than 10% of a particular species on the site. This is to improve the biosecurity, wayfinding, and seasonal interest;**
the scale of planting should also relate to its potential function as mitigation for landscape impact. Tree planting should be of a scale to grow above roof lines to break up areas of development and to help assimilate development into the landscape setting;
a landscape management plan has been prepared and submitted which explains the aftercare and maintenance programmed for the landscaping.**

Note: All design principles are applicable to all scales of development unless otherwise specified; *minor applications, **major applications