The CANOPY_Londons Urban Forest_A Guide for Designers

8/12/2019 The CANOPY_Londons Urban Forest_A Guide for Designers

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Londons Urban Forest:A Guide for Designers, Planners and Developers

February 2011


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Contents

02 The Challenge04 City Pressures06 Green Benefits08 Real Value10 Technical Solutions12 Podium Planting14 Grounded People16 Case Study: Developer Approach18 Case Study: Designer Approach20 Case Study: Planning Approach22 Knowledge Tree24 The Future

Foreword

London is one of the greenest cities in the world viewedfrom the air, more than half of the area is lush green spaceor water. This is a wonderful and precious asset that I amdetermined we protect to improve quality of life.

Expanding tree cover is a vital part of my vision to createa safer, stronger, greener and cleaner London. Through my

RE:LeafLondon campaign I aim to increase Londons treecover by 5% by 2025. This will provide a myriad of benefitshelping to cool the city, provide shading, sweeten theair by reducing air pollution and generally add to a morepleasing, attractive urban aesthetic.

In addition to taking steps to increase the numbers of newtrees being planted, we must also ensure that we reversethe decline of existing mature trees that has occurred overrecent years and seek opportunities to encourage a growthin their numbers.

This is a comprehensive and invaluable guide to how wecan work together to achieve this.

Boris Johnson, Mayor of London


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/03 The Challenge

Our towns and cities are under pressure. Environmental, socialand economic demands are making it difficult for us to createhealthy, liveable and economically resilient places.

As we strive to improve our urban environments and tacklecity pressures, we are discovering the extent to which treesare a significant contributory factor in achieving these aims.

In the last few years a growing body of research has madeit clear that trees are a cost-effective way of bringing a widerange of benefits to the environment, to individual people andto society as a whole. At the same time, studies have shownthat in urban areas all over England our trees are under threat.Large trees are being cut down and are being replaced bymuch smaller varieties. The wrong type of trees are beingplanted in the wrong places. We need to reverse this trend.This guide will help you to do that and to create healthier,more liveable and more successful places.


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Insurance5-10 percent of the trees cut downin London (2008-2009) were

removed due to insurance claims.

NeglectMost trees planted will out-live us,so invest in their preparation andmaintenance and they could repayyou and future generations.

Fear/IgnoranceFalling branches, subsidence, fruitdrop, poisonous seeds and othernatural events caused by trees canall be managed if you select theright place for the right tree.

VandalismTrees and especially young treesare prone to vandalism. Goodmaintenance and adequate treeprotection measures are key inreducing vandalism.

DevelopmentsSome trees may be lost todevelopments, but our guidance

is intended to reduce this loss andassist in finding sites for new trees.

Road AlignmentStreet trees can fall victim tocarriageway realignment. Whenthey are replaced, the new treesshould be of equal merit and alsoable to grow to their full size.

Climate ChangeSome tree species such as SilverBirch may be less successful in thefuture. We say broaden the rangeof trees planted and rememberright place, right tree.

Old AgeWe all get old and trees are nodifferent. However, their life-spans can be extended with goodpreparation and maintenanceduring their life time.

Trees are facing enormous pressures inthe Capital today; in places their veryexistence is threatened and scope fornew planting increasingly constrained.The London Assemblys ChainsawMassacre report highlighted the lossof street trees in London indicating thatmore large species trees are being cutdown than are being replaced.

The value of trees is rarely considered inthe cost-benefit analysis of developments.This is unfortunate and surprising, as manytrees will outlive these new developmentsand their owners.

We all have a relationship with the naturalenvironment and recognize that natureand greenery are good for our well-being.As well as our intuitive connection withtrees, there are proven benefits that havebeen identified by professionals.

/05 City Pressures

A London Plane

outside the

Lloyds Building

By following best practice and takingadvice from arboricultural professionals,we can accommodate larger trees inthe public realm.Dana Skelley, Director of Roads, Transport for London


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/07 Green Benefits

BiodiversityAn increase in tree diversitywill benefit a host of insects,birds and mammals in ourtowns and cities.

AestheticMost Architects and Plannerswould agree that trees bring asense of place and maturity toschemes, whilst larger speciestrees help to create a morehuman scale to old and newdevelopments.

Energy SavingIt has been proven that largetrees located alongsidebuildings can act as asecondary insulating layer,regulating temperatures aroundbuildings. Deciduous trees canalso help keep buildings coolin the summer and warmer inthe winter.

Air QualityTrees can help to filter fineparticles from the air.

Landscape ScreeningNot everything in cities isaesthetically pleasing and insome instances, trees and othervegetation can be of assistancein screening undesirable views.

Property ValueTree lined streets have beenproven to increase house pricesby as much as 15%. Most peoplechoose to live in and/or aroundtrees wherever possible.

We appreciate that it is not possible to retain or locate treesin every new development but we hope that good treesolutions will be incorporated wherever possible.

CoolingTrees provide cooling by shadeand evaporation from theirleaves; which means that largercanopy species are better.All trees require adequaterooting space and a watersource. Direct contact withthe earth is preferable.

Micro ClimateTrees help to reduce extremesof temperature.


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/09 Real Value

Trees are assets which increase in valueover time. It is now possible to quantifythese values in monetary terms and applyan economic analysis to the benefitsof urban trees including increases inproperty values, energy conservation,air quality improvement, CO2reductionand storm water control. Current researchis exploring methods for quantifying thevalue of trees in terms of additional gainssuch as human health and well-being andcrime reduction.

In reality, trees have to balance withmany other considerations that are placedon a project. Whilst the constraints andproblems are well known, some of thebenefits of trees are less publicised.The following points highlight the broaderbenefits of trees.

Cost ReductionTrees help improve theenvironmental performance

of buildings a well planteddevelopment can lower heatingand cooling costs by 20%.

Asset Value IncreaseMaximise your investment. Treeshave the potential to increaseproperty values by 7% to 15%.

Environmental EnhancementsTurn off the air conditioning andturn down the heating. Urban treeshelp reduce temperature extremes.

Social ImprovementsEvidence has shown that in somelocations areas with high numbersof trees experience less crime.Trees also help to reduce noisepollution, absorbing and deflecting

sound.

Create a Sense of PlaceTrees help to improve localidentity. Large species treesequal big improvements. Treescan encourage social activities inareas with higher tree numbers,creating stronger and friendliercommunities.

Safer StreetsTree-lined streets promote calmerdriving so are safer for pedestrians

and thus enhance both walkingand cycling.

Health and Well-beingTrees improve the urbanenvironment. Trees and urbangreening have been shownto reduce stress levels and soincrease feelings of well-being.

Stabilising StormsTrees help reduce the effects offlash flooding by interceptingrainfall and can readily absorbwater through their fibrous roots.

Wildlife EnhancementsTree planting is a great way ofincreasing biodiversity. They area major element in creating urbangreen links and wildlife corridors,as part of green infrastructure.

The insurance industry understands theimportance of urban trees. We believe theycan play an important role in keeping ourcities cool as climate change takes effectand have taken pro-active steps such asadvising on safe distances from buildingsfor new plantings.Swenja Surminski, Association of British Insurers

EnvironmentGill SE, Handley JF, Ennos ARand Pauleit, S (2007)

Adapting Cities for Climate Change:the Role of the Green Infrastructure.Built Environment 33 (1) pp 115-133

EconomicAnderson LM and Cordel HK (1988)Influence of Trees on ResidentialProperty Values in Athens, Georgia:A Survey Based on Actual Sales Prices,Landscape and Urban Planning 15:153-164

Morales DJ (1980)The Contribution of Trees to ResidentialProperty Value: Journal of Arboriculture6 (11): 305-308

CABE Space (2005)Does Money Grow on Trees?Commission for Architecture and theBuilt Environment, London

SocialNational Urban Forestry Unit (1999)Trees and Healthy Living, National

Conference, Wolverhampton,UK, National Urban Forestry Unit,Wolverhampton

Mudrak LY (1982)In the Environmental Benefits ofVegetation at a Global Local andPersonal Level: A Review of theLiterature, Green Releaf, HorticulturalTrades Association and Royal BotanicalGardens, Kew

Health and Well-beingNational Urban Forestry Unit (1999)Trees and Healthy Living, NationalConference, Wolverhampton,UK, National Urban Forestry Unit,Wolverhampton

Mudrak LY (1982)In the Environmental Benefits ofVegetation at a Global Local andPersonal Level: A Review of theLiterature, Green Releaf, HorticulturalTrades Association and Royal BotanicalGardens, Kew


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PlantersAvoid where possible.Planters need more intensivemaintenance and can limit treegrowth. As always, right place,right tree. lllllXXXXX

11 Technical Solutions

Roof GardensAlthough more complex, treescan be planted on roofs insome locations. Developers anddesigners must seek advicefrom an arboriculturist and astructural engineer. lllllXX X XX

Micro Climates/WindTunnellingTrees make a significantcontribution to improvingthe microclimate in terms ofurban cooling, rain interceptionand storm water management aswell as aiding the environmentalperformance of buildings.

Structural LandscapeThese constrained locationsshould only occur whereattempts to plant treesdirectly into the soil havefailed. Maximise the soildepth, propose the right treefor the location, and alwaysseek professional advicefrom a landscape architect,arboriculturist and a structuralengineer. lllllXX XX X

Key

Expense of installation

lllll Benefit

X XXXX Maintenance

Time in Years

30

20

10

UtilitiesLocating new street trees inLondon is notoriously difficult.Do not rely on ground radar tofind all of the utilities. Whereverpossible, dig trial holes to avoiddisappointment. Most treeroots grow in the first 600mmdepth of soil. Services should belocated outside this zone.

Newly Constructed CentralReservationsFootways can be a difficultplaces to locate street treesdue to utilities and otherobstacles. Therefore, plantingin the central reservation canbe an alternative solution forstreet tree planting. lllllXXXX X

Developers and designers should always seek advice froman arboriculturist, highways and structural engineers.

eet Treeseets present the bestportunity within the urbanlm for larger species treesgrow to maturity. Suitable volume and root space

equired. lllXXX


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Build a Green Structural TeamInvolve engineers, architects, landscapearchitects, arboriculturists and otherspecialist consultants in an integrated,

joined up approach.

Grow the Team TogetherEarly involvement of all consultants isneeded to ensure that the technicalrequirements are fully and adequatelyintegrated e.g. slab design, drainage,and irrigation systems.

Know Your Trees and Substrate

Ensure adequate soil volumes for theselected species so they can grow tomaturity. This will require that sufficientsoil preparation is undertaken.

Right Place, Right TreeIdentify appropriate size of trees forplanting to promote longevity.

Irrigation Maintenance PlanInclude sustainable water managementsystems.

Design and Manage GrowthAccess for regular maintenance operationsneeds to be provided.

Invest in Green FuturesPrepare management plan and costs

for long term tree care, allowing for theremoval and replacement of failed trees.

13 Podium Planting

In many situations planting trees abovestructures is the only way to include treesin new developments. The larger growingspecies offer the greatest benefits forthe future of our cities and it is hopedthat trees in structured landscapes canbe retained to grow to maturity throughadequate provisions at an early stage inthe development process.

201

Bishops Gate

RestrictedTree Pits

RoofGardens

CourtesyofBritishLand

RaisedPlanters

With good planning and design, largetrees can assist with the energy efficiencyof individual buildings and benefit localareas in our towns and cities by improvinglocal temperatures, wind conditions, andproviding water storage.Sarah Cary, Sustainable developments executive, British Land

Podium

Planting


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15 Grounded People

Trees are an essential part of the urbanpublic realm, both practically andaesthetically. They bring many thingsincluding focus, shade, calm or simplya view on the changing seasons.Robert Noel, Managing Director, London Portfolio,Land Securities

Trees make a difference to the way we allrespond to a particular place and help tocreate a much needed sense of identity.Ann Skippers, President RTPI 2010

Trees improve the street environment inwhich Londoners live and work so I willdo all I can to save the trees we haveand campaign for more trees to protectLondons open spaces.Boris Johnson, Mayor of London

In any civilised society access to high-quality public space should be afundamental human right. Everyoneshould be able to see a tree from theirwindow, sit on a bench, walk to a squareand cycle to a park.Lord Rogers of Riverside, Rogers Stirk Harbour Partnership

Barking

Town Centre

Arboretum


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1 7 Case Study: Developer Approach

St Andrews,Bromley-by-BowDeveloper Approach(Building for Life 2010award winner)

St Andrews is a landmark regenerationscheme being delivered in partnership by

Barratt Homes, the London DevelopmentAgency, the Homes and CommunitiesAgency and Circle Anglia.

The development, currently underconstruction, will bring 964 high-qualitynew homes, a brand new NHS health carefacility, one hectare of gardens and parksand a new community facility.

It is crucial for our residents that weprovide a pleasant environment forpeople to live and play and we valuethe contribution that well-designedopen space and greenery can bringin enhancing the quality of ourdevelopments.

When completed, the St Andrewsdevelopment will be a fantastic amenityfor the entire local community, providingsafe and accessible green space whichis a welcome counterbalance to thenearby A12.

Alastair Baird, Regional ManagingDirector of Barratt London

Sitelayout

Nexus,Phase1

Official Title

St Andrews,

Bromley-by-Bow

Location

Bromley-by-Bow,

Tower Hamlets

Owners

Barratt Homes

Designed by

Masterplanned by

Allies and Morrison.Phases 1, 4 and 5 designed

by Allies and Morrison.

Phase 2 designed by

Maccreanor Lavington.

Phase 3 designed by

Glenn Howells

Development Stage

Under construction

Union,BlockB


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Maggies CentreDesigner Approach

Rogers Stirk Harbour + Partners andthe Dan Pearson Studio completedthe Maggies Cancer Caring Centre inHammersmith 2008. The building did notimpact on a nearby London Plane treeand additional trees/plants were planted

creating a comfortable, uplifting spacefor visitors.

Maggies London is on a very busy cornerof the Fulham Palace Road, with one ofthe only remarkable features being the lineof mature London plane trees that formthe perimeter boundary of Charing CrossHospital. The interaction between thebuilding and its surroundings was integralto the design, with views both into and outof the building being carefully managedwith the help of courtyard gardens andexternal landscape. Over 80 new treesnow envelop the building to shelter itfrom the noise and pollution of the busymain road with the positioning of thebuilding being greatly influenced bythe line of existing trees. The entrancepathway winding through the existingplane trees instigates a transition betweenthe main hospital and the non-institutionalenvironment of Maggies.

Will Wimshurst, Project Architect,Rogers Stirk Harbour + Partners

19 Case Study: De signe r App roach

Official Title

Maggies Cancer Caring

Centre

Location

Charing Cross Hospital,

Hammersmith

Owners

London Borough of

Hammersmith PCT

Designed by

Rogers Stirk Harbour

+ Partners

Development Stage

Completed 2009 and

awarded the RIBA Stirling

Prize and other awards

LorraineWorpole

LorraineWorpole

7-tLtd(www.7-t.co.uk)


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/21 Case Study: Plann ing Approach

Bankside Urban ForestPlanning Approach

Bankside Urban Forest highlights theimportance of partnership working acrosspublic/private and third sectors to maximisethe effective utilisation of investment. Thekey stakeholders include: Better Bankside,Southwark Council, Tate Modern, Design

for London, Cross River Partnership,The Architecture Foundation, BanksideResidents Forum, Bankside Open SpacesTrust, Native Land and Land Securities.

Bankside Urban Forest is about makingBankside a better place to live, work andvisit. It is a strategy for enhancing publicspaces including streets, pavements,squares and parks in the Bankside area: It encourages investment in public spaces. It encourages imaginative and high-

quality improvements. It also helps to coordinate individual

projects with an overall vision. Too oftenpublic space projects fail to join up witheach other, creating confusing andchaotic places.

A forest is a place with a strong overallcharacter, which allows diverse activities,freedoms and places within it. The aimof the Bankside Urban Forest is to achievethis quality in a city context. The strategyis not literally to turn the area into a forest,although it does create opportunities forgreening, using trees, planted walls, andother means.

Official Title

Bankside Urban Forest

LocationBankside Southwark

Owners

Partnership of above

organisations coordinated

by Better Bankside

Designed by

Witherford Watson Mann

Development StageOngoing

WitherfordWatsonMannArchitects

WitherfordWatsonMannArchitects

newsurface, possiblyof porphyrysetts andpre-cast slabs or stonestoreclaimedroadsurface

newgreenrooftocafe

lightingtoarch

MickeyLee,MediaMixer

CaseStudy


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/23 Knowledge Tree

This page shows some key documentsrelating to trees and their implementationin the urban realm. Whilst funding andstakeholders may change over time, theprinciples for good tree planting areconstant and are based on the rightplace, right tree approach and followingbest practice planting and maintenanceguidance as well as seeking advice fromexperts where relevant.

Promotion and FundingRE:Leaf(GLA 2011)www.london.gov.uk/releaf-london

The Big Tree Plant(DEFRA & The Forestry Commission 2010)www.defra.gov.uk/news/2010/12/02/tree-plant

London PolicyThe London Plan

A Tree and Woodland Frameworkfor London

Technical GuidanceDepartment for Transport: Manual for

Streets I and II

CLG: Tree Roots in the Built Environment

Guidelines for the Planning, Installation& Maintenance of Utility Apparatus inProximity to Trees (V4) NJUGwww.njug.org.uk/publication/51

Joint Mitigation ProtocolLTOA (2008)London Tree Officers Associationwww.ltoa.org.uk

Other GuidanceCLG: Trees in Towns II

Mayor of London: Londons GreatOutdoors Better Streets; Better Green& Water space

CABE: From Grey to Green Campaignwww.cabe.org.uk/grey-to-green

CABE: Sustainable Citieswww.cabe.org.uk/sustainable-cities

Natural England: A Natural Developmentwww.naturalengland.org.uk/naturaldevelopment

RE:Leaf

Guidelines forthe Planning,Installation &Maintenance ofUtility Apparatusin Proximity toTrees (V4) NJUG

The Big TreePlant

Joint MitigationProtocolLTOA (2008)


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The Future

Organisations and individuals who havecontributed to the TDAG include:4D Landscape DesignArboricultural AssociationArupAtkins GlobalBarcham TreesBarrell Tree CareBennetts AssociatesBlackwood Murray ArchitectsBrady Mallalieu ArchitectsBristol Street TreesBuilding Research Establishment (BRE)CABECanary Wharf GroupCapita SymondsCgMS Planning ConsultantsCIRIACity of LondonCity of WestminsterCivic TreesDesign for LondonEnglish HeritageEnvironment AgencyFarrellsForestry CommissionGardiner & TheobaldGeosynthetics LtdGlendale Managed ServicesGreater London AuthorityGreen Roof ConsultancyGreening the Gateway Kent & MedwayGrosvenorGVA Grimley

Hi-Line ConsultancyICE (Institution of Civil Engineers)ICF (Institute of Chartered Foresters)

ISA (UK & I Chapter)Land SecuritiesLandscape InstituteLeeds Metropolitan UniversityLondon Borough of HackneyLondon Borough of WandsworthLondon Parks & Green Spaces ForumLondon Tree Officers AssociationMarishal ThompsonMouchelMyerscough CollegeNational Association of Tree OfficersNational and London Joint Utilities GroupsNatural EnglandNUAGPeter Osborne, Independent InsurerPlaces for PeopleRSA Group (formerly Royal and Sun)TCPA (Town and Country PlanningAssociation)Thames WaterThe Royal ParksThe Tree CouncilThe Woodland TrustTorbay City CouncilTransport for LondonTree and Landscape Evaluation SystemsTrees for Cit iesTreework Environmental PracticeUniversity of EssexUniversity of ManchesterUrban Design LondonVictoria BIDWillerby Landscapes

Zurich Municipal

... and growing!

The FutureThe Trees & Design Action Group (TDAG) is a pioneeringgroup of individuals, professionals and organisations from boththe public and the private sectors who have come together toincrease awareness of the role of trees in the built environmentthroughout the United Kingdom.

The Group shares the collective vision that the location of

trees, and all the benefits they bring, can be secured for futuregenerations by influencing the planning, design, constructionand management of our urban infrastructure and spaces.

TDAG assists developers, designers and planners in addressingtrees issues by seeking to influence policy and pooling existingbest practice into one navigable point.

More information about TDAG can be found onwww.tdag.org.uk

Design:reduction.org

The Canopy was writtenand produced by:

Paul CampbellDesign for London

Sue JamesCapita Symonds

Chris EdwardsCABE


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Trees and Design Action Groupwww.tdag.org.uk

City of London

Information

C t

The best friend of man is the tree. When we use thetree respectfully and economically, we have one ofthe greatest resources on the earth.Frank Lloyd Wright

Documents

The CANOPY_Londons Urban Forest_A Guide for Designers