PROPOSED RESIDENTIAL DEVELOPMENT IFIELD COMMUNITY COLLEGE ... · PROPOSED RESIDENTIAL DEVELOPMENT IFIELD COMMUNITY COLLEGE CRAWLEY ... planning application for residential development

BDW SOUTHERN COUNTIES LTD

PROPOSED RESIDENTIAL DEVELOPMENT IFIELD COMMUNITY COLLEGE

CRAWLEY

Arboricultural Impact Assessment

June 2015 8842_AIA.001

COPYRIGHT

The copyright of this document

remains with Aspect Arboriculture Ltd.

The contents of this document

therefore must not be copied or

reproduced in whole or in part

for any purpose without the

written consent of

Aspect Arboriculture Ltd.

Aspect Arboriculture Ltd Hardwick Business Park

Noral Way Banbury

Oxfordshire OX16 2AF

t 01295 276066 f 01295 265072

e [email protected] w www.aspect-arbor.com

June 2015 8842_AIA.001

CONTENTS

1. INTRODUCTION 1

2. POLICY CONSIDERATIONS 3

3. STATUTORY DESIGNATIONS RELATING TO ARBORICULTURE 5

4. BASELINE INFORMATION 7

5. TREE CONSTRAINTS 8

6. IMPACT ASSESSMENT 12

7. CONCLUSIONS 18

8. RECOMMENDATIONS 19

APPENDICES

SURVEY BOUNDARY PLAN APPENDIX A

TREE SURVEY SCHEDULE APPENDIX B

TREE PRESERVATION ORDER PLAN APPENDIX C

TREE CONSTRAINTS PLAN APPENDIX D

PRELIMINARY TREE PROTECTION PLAN APPENDIX E

TREE SURVEY METHODOLOGY APPENDIX F

Ifield Community College, Crawley June 2015

Arboricultural Impact Assessment 8842_ AIA .001

1

1 INTRODUCTION

1.1 Instruction

1.1.1 Aspect Arboriculture has been commissioned to prepare an Arboricultural Impact

Assessment (AIA) to supplement BDW Southern Counties’ planning application for

residential development at the former Ifield Community College site, Crawley.

1.1.2 The proposals put forward relate to: Erection of 193 units (77 houses, 2 maisonettes,

7 Coachouses and 107 apartments), together with associated car parking, open

space, landscaping and vehicular access from the existing junction on Lady Margaret

Road.

1.2 Scope

1.2.1 This work provides an appraisal of the relationship between the application area’s

existing trees and the development proposals. In line with current industry advice, the

arboricultural information presented herein has been guided by the recommendations

within British Standard document BS5837:2012 ‘Trees in Relation to Design,

Demolition and Construction’.

1.3 Site Description

1.3.1 The site is located within West Crawley and comprises an irregular parcel of land

bound by existing residential development to the north, west and south and areas of

maintained recreational ground to the east (refer to Appendix A). Following

demolition of former college facilities in 2006, the site interior now consists of a matrix

of defunct hard surfaces and scrub colonisation.

1.3.2 The site is influenced by a number of mature Oaks, considered to be remnants of

former parkland, set amongst younger trees left over from previous soft landscaping

arrangements and residential boundaries. With the exception of the western

boundary which is void of onsite tree cover, the trees are distributed across the site

as a mixture of outlying standards and those set within established boundary

hedgerows.



2

1.4 Limitations

1.4.1 This assessment has been prepared in respect of proposed development and should

not be interpreted as a report on tree health and safety. Reasonable effort has been

made to identify visible defects whilst undertaking the tree survey; trees are however,

prone to natural failure without warning therefore no guarantee can be made as to the

absolute safety of any of the trees surveyed. Aspect’s opinion of tree condition and

structural potential is therefore valid for a limited period of 12 months from the date of

inspection. Validity is assumed in the absence of inclement weather and no change

to the trees existing context.

1.4.2 This work relates to arboriculture, therefore reliance should not be given to comments

made in respect of other disciplines i.e. landscape, ecology or civil engineering

without first consulting an appropriate expert.



3

2 LOCAL POLICY CONSIDERATIONS

2.1 Administration

2.1.1 The site occurs within the administrative boundary of Crawley Borough Council

(CBC). In terms of development control, the Council has a statutory obligation to

ensure adequate provision is made for the preservation of trees through Section 197

of the Town and Country Planning Act (1990). In response to this requirement, the

Council has prepared specific standards and policies which include trees within their

primary development control documents; understood to be the Core Strategy and

saved polices of the Crawley Local Plan (2000).

2.1.2 A review of this information has been undertaken to assist reaching balanced

conclusions regarding the significance of the site’s existing trees, and the influence

upon them arising from the proposals put forward.

2.2 Crawley Borough Local Development Framework Core Strategy (October 2008)

2.2.1 Trees are considered implicitly as natural features, wherein the Council recognises

the important contribution that trees make to the amenity of urban and rural areas; a

distinction is made for the desire to retain aged and veterans trees in particular.

2.3 Crawley Local Plan (2000)

2.3.1 Policy BN20 Landscape: In the context of proposed development, there is

presumption in favour of tree retention pursuant to which the applicant is expected to

identify and retain important tree cover. Although there is a presumption against the

clearance of trees and particularly woodland, the Local plan does not preclude the

removal of trees to enable development. The removal of trees is permitted if it can be

demonstrated that the proposed development will provide opportunities to enhance

local landscape and be of value to nature conservation. The provision of a

comprehensive replanting scheme is therefore a requisite expectation where tree

removal is necessary as part of development.

2.3.2 “Proposals for development will not normally be permitted if it will adversely affect

important natural landscape features, including woodlands, water courses and

adjacent land, trees and hedgerows. If development is permitted, the replacement of



4

landscape features lost may be required (see Policy GD5). The Borough Council will

undertake and encourage improvements to the amenity and recreational value of

these areas”.

2.4 Policy BN21 Tree Preservation Orders:

As part of the Councils strategy for considering trees in the context of development,

the council may choose to make Tree Preservation Orders. The council will resist

proposals that threaten the loss of trees covered by a TPO, particularly where the

trees make a particularly important contribution to amenity of a site and it’s setting.

2.4.1 “Where an application is necessary for the removal of a tree protected by a Tree

Preservation Order (T.P.O), permission will only be granted if the tree is unhealthy or

dangerous, or if it no longer contributes to public amenity. The planting of

replacement trees may be required. Work on trees protected by T.P.O.s may be

permitted if it does not detract from the health or appearance of the tree”.

2.5 Policy BN1 Conservation Areas: When considering safeguarding the character or

appearance of areas considered to be of special interest, the Council include trees

within the list of criteria to take into account (refer to criterion iii, “the quality of open

spaces, trees and other landscape features”.

2.6 Comment

2.6.1 This document has been prepared in direct response to the CBC’s Policy requests. It

provides an assessment of the trees within influence of the application area, their

suitability for integration within a completed development, an assessment of the

potential for tree loss/tree works, and to inform opportunities for replacement tree

planting.



5

3 DESIGNATIONS RELATING TO ARBORICULTURE

3.1 Tree Preservation Order(s)

3.1.1 The effect of a proposed development on trees is a material consideration therefore

CBC has a duty to ensure that provision is made for protecting important trees when

granting planning permission, this includes the use of Tree Preservation Orders

before a planning application is made (pursuant to Policy BN21). In terms of

development a TPO serves to safeguard high quality trees during design and to

enforce their protection during site clearance and building operations.

3.1.2 On site discussion with the Councils Arboricultural Officer revealed that some of the

site’s trees are scheduled within Tree Preservation Order 1984 (Pers. Comm.

November 2014). A copy of the TPO plan is in provided in appendix C.

3.1.3 Although the order relates to a much wider area, it includes the following trees which

are within influence of the application site:

T1 Category A English Oak (TPO T14)

T2 Category U English Oak (TPO T13)

T19 Category B Common Ash (TPO T18)


T21 category U English Oak (TPO T20)

T22 Category C English Oak (TPO T21)

T23 Category B English Oak (TPO T22)

T24 Category C English Oak (TPO T23)

T27 Category C Silver Birch (remnants of TPO G5)

T28 Category C Purple Plum (remnants of TPO G5)

T29 Category C Weeping Willow (remnants of TPO G5)






6

3.2 Conservation Area(s)

3.2.1 Trees within conservation areas that are not subject to a TPO are afforded protection

through a Section 211 of the Town and Country Planning Act 1990. Under a section

211 ‘notice’ the Council requires six weeks prior notice of an intention to fell or work

on a tree within a conservation area. The purpose of the requirement is to provide

either LPA with the opportunity to make a TPO if considered to be appropriate for the

tree(s) in question (pursuant to Policy BN1).

3.2.2 Online enquiries to CBC show that the site does not fall within a conservation area

(Pers. com. November 2014).



7

4 BASELINE INFORMATION

4.1 Tree survey

4.1.1 Pursuant to the Council’s policy requirements, the site’s existing trees have been

surveyed under guidance provided by BS5837 (2012). Existing trees within influence

of the application area can subsequently be described by reference to 34no.

individual trees, 4no. groups1 of trees and 1no. hedgerow2. A copy of the survey

methodology is included at Appendix F.

4.1.2 Drawing SBP 001 in appendix A indicates the extent of the tree survey which

corresponds to the application site boundary. As a precaution against harming offsite

trees, the survey area is shown to extend to trees within third party ownership that

may be influenced by future development on the site, e.g. through overhanging

canopies or potential for root development within the site.

4.1.3 The survey provides a record of the species assemblage, dimensions, age,

physiological and structural condition, and the perceived visual importance of each

tree/hedgerow. Full details of each tree, group of trees and hedgerow are provided in

schedule in appendix B and the distribution of the trees is illustrated in appendix D.

4.1.4 The tree survey seeks to provide a baseline on which to balance the demands of the

layout with tree retention and opportunities for enhancing the existing tree stock. To

achieve this position, the tree survey has been undertaken independently of a

detailed proposed layout and prior to any form preparatory works occurring on site.

4.1.5 In all instances, the tree survey has been undertaken visually, from ground level and

from land on which access was permitted. Where access was not available or

practicable, measurements have been estimated; this also typically applies to the

trunk diameters of small trees occurring as understory to larger independently

surveyed tree groups.

1 The term ‘group’ is used to define trees that form a cohesive arboricultural feature, i.e.

aerodynamically, visually or culturally. The assessment of individuals within groups has also

been undertaken where it will be advantageous to make such a differentiation.

2 Hedgerows and substantial internal or boundary hedges are recorded in a similar fashion to

groups with distinctions made for woody plants that comprise distinct trees or significant

variations in the structure/composition. It is not within our scope of work to identify the

importance of hedgerows as it is defined within the Hedgerows Regulations 1997.



8

5 TREE CONSTRAINTS

5.1 Design Principles

5.1.1 Proposals for development of the site have been informed by the direct and indirect

constraints provided by the existing tree cover. Over a number of months the

emerging designs have been tested against the tree constraints, incurring revisions to

the design that seek to achieve confident long-term retention of existing trees,

particularly those of importance to amenity.

5.1.2 A summary of the constraints considered during design is provided under the

following subheadings. Details of each of the listed constraints specific to individual

trees, groups and hedgerows is provided within the Tree Schedule found in Appendix

B and illustrated on the Tree Constraints Plan within Appendix D.

5.2 Canopies

5.2.1 The distribution of the Site’s canopy area is illustrated on the Tree Constraints Plan in

appendix D. Canopies have been measured at cardinal points for individual trees and

informed by a topographical survey.

5.2.2 It has been Aspect’s default position that no proposed buildings are sited within the

canopy spreads of retained trees; where it is necessary for proposed structures to be

sited within close proximity to canopies, this has been balanced with an allowance for

future growth and with species attributes.

5.2.3 Vertical canopy clearance has been referenced where it is necessary to permit

access beneath canopies, albeit where justifiable. Our default position has been to

avoid access beneath canopies where possible.

5.2.4 Crown height is provided in order that the design is able to prevent an unreasonable

obstruction to daylight associated with canopy shade. It is however accepted that

some shade may be desirable or acceptable in certain circumstances.



9

Root Protection Areas

5.2.5 RPAs are illustrated within Appendix C as a radius from the trunk in plan form and

represent the minimum soil surface area required to enable each tree/group’s

confident retention. It has been our default position that permanent features of the

development are precluded from this area during design unless it can be

demonstrated to be necessary to accommodate an incursion considered to be within

acceptable limits.

5.2.6 It is our opinion that the morphology and disposition of tree roots will, in some

instances, have been influenced by barriers and restrictions to root development, e.g.

adopted highways.

5.2.7 Where the shape of an RPA has been altered, this has been done to include areas

that are considered to be more advantageous to root development. During

manipulation, the area of the RPA has not been reduced.

5.2.8 In accordance with table.2 of BS5837:2012, the relative quality of the trees in respect

to suitability for retention is illustrated by the colour of their Root Protection Area.

5.3 Grading Categories

5.3.1 The quality of the trees is described by reference to BS5837 categories for tree

classification; there are four categories within this model, all of which feature on the

site. A synopsis of the trees is proved below by reference to category.

5.4 Category A tree cover

5.4.1 Representing the principle arboricultural features of the application area, category A

tree cover occurs less frequently than the other classifications. It has been reserved

for 4no. English Oak (T1, T25, T26 & T30) considered be very good examples of their

species and of visual significance to the application area.



10

5.5 Category B tree cover

5.5.1 Category B trees are present throughout the application area, occurring as

standalone trees which demonstrate remediable visual defects yet lacking the quality

normally expected of a very good example of the species within the setting.

5.5.2 Category B trees represent moderate arboricultural features of the existing site and

are considered to be important trees that is desirable to retain within a completed

development; they subsequently represent a significant constraint during the

architectural design process and are slightly more abundant than category A tree

cover.

Refer to: T19 Common Ash; T23, T33, T34 English Oak & T31 Common Lime

5.6 Category C tree Cover

5.6.1 With exception of category U trees, all remaining tree cover identified on the site and

its boundaries is considered to represent generally unremarkable examples of its

type i.e.: trees that demonstrate compromised structure, signs of stress; trees of

indifferent structural and physiological appearance and those providing limited or

transient benefits which may be readily replaced. This includes trees that are not

conferred a higher value when present in numbers.

5.6.2 The retention of category C trees is recognised as important where practicable during

design as they help maintain the semi-rural appearance of the site, nonetheless they

are of less priority for retention than category A and B tree cover.

5.7 Category U tree cover

5.7.1 Where tree numbers are enclosed by brackets on the appended plans, this denotes

category U tree cover. Category U trees are of particularly reduced physiological

and or structural condition, such that they are not considered suitable for retention as

living trees in the short term (circa 10 years) or appropriate to retain within the

proposed setting.

Refer to: T2, T20 & T21 English Oak (TPO T13, T19 & T20 respectively); T17, T18

Apple



11

5.7.2 Despite representing the least level of constraint during design of the proposals,

category U trees are acknowledged to have existing or potential ecological value

which it might be desirable to preserve3

3 Quantifying this value is outside the scope of this document and is the focus of a separate ecological

study prepared by others as part of the current application.



12

6 IMPACT ASSESSMENT

6.1 Preliminary Tree Protection Plan

6.1.1 In keeping with the recommendations of BS5837:2012, our assessment of the

proposed impact upon existing trees is presented in the format of a Tree Protection

Plan incorporating the entire application area (Appendix E).

6.1.2 The purpose of the TPP is to identify: a) trees to be retained and integrated within the

proposed setting, b) illustrate safeguarding measures to ensure that retained trees

are not harmed, either during the course of construction, or as a result of the

development; and lastly, c) identify trees that it is necessary to remove in order to

implement the development and mitigate with new tree planting.

6.1.3 Our assessment and the TPP are informed by the tree survey and constraints plan

balanced with the requirements of the layout and adopted policy. The tolerance of

the trees to disturbance based on species, age, condition and the presence of

surrounding trees and features of the existing site has also been considered.

6.2 Tree Removals

6.2.1 It is our professional opinion that trees should be recommended for removal where, a)

it is necessary and unavoidable to site development within close proximity to existing

trees, such that they cannot be confidently retained as living features, and/or b),

where the amenity value of the tree will be significantly reduced as a result of the

proposals, particularly if already of a low retention priority. In both cases, there is a

presumption that removal will be justified by the provision of replacement trees of

equal or improved suitability for the setting.

6.2.2 Trees recommended for removal are distinguishable from retained trees through the

absence of an RPA or a hatched canopy; identification numbers are shown coloured

red and canopy edges are both dashed and coloured red.

6.2.3 Excluding Category U trees, it is necessary to recommend the removal of 18no.

individual trees, 1no. group of trees and 1no. section of hedgerow to implement the

proposals these are listed within Table 1 (overleaf).



13

6.2.4 Category U trees are listed within Table 1 for completeness on account that their

removal is recommended in the interest of sound arboricultural management

associated with their reduced life expectancy in both the existing and the proposed

setting.

6.2.5 There are seven trees recommended for removal that are scheduled within the TPO

(listed below). It has been agreed with the Council’s Arboricultural Officer that despite

their TPO status, these trees are of less importance to the amenity of the site and of

reduced life expectancy when compared to the remaining TPO population.

T2 Category U English Oak (TPO T13):

T19 Category B Common Ash (TPO T18);


T21 category U English Oak (TPO T20)

T27 Category C Silver Birch (remnants of TPO G5)

T28 Category C Purple Plum (remnants of TPO G5)

T29 Category C Weeping Willow (remnants of TPO G5)

6.2.6 It is considered that the remaining category C tree removals (in addition to category U

trees) are of a current size and type that ensures that they can be readily replaced

with tree plantings of improved longevity.

6.2.7 In order to provide construction room for plots 144-159, it is necessary to recommend

the clearance of 2no. short sections of hedgerow H1 subject to being restocked

following construction.

Table.1: Tree removals to implement proposed development (by category)

B C U

T19 Common Ash T3-T13 Common Lime [2] English Oak T14 Silver Birch [17] Apple T15 Bird Cherry [18] Apple T16 Apple [20] English Oak T27 Silver Birch [21] English Oak T28 Purple Plum T29 Weeping Willow G1 Common Ash, Cherry H1 (Partial) Hawthorn, Hazel



14

6.3 Access facilitation Pruning

6.3.1 It will be necessary to prune boundary group G2 by c.4m to facilitate the construction

of proposed car parking and built forms close to the southern boundary of the site. In

addition, pruning of H1 by c.1m will be required to provide construction room for plot

48 near to the eastern boundary.

6.3.2 Throughout the entire site, dead branches should be entirely removed from the canopies

of retained trees. Although this work is not required to facilitate construction, it will help

mitigate the risk of future tree related hazards emerging. It would be prudent for this

work to coincide with clearance work on account that access to the trees will be

unimpeded.

6.3.3 All tree works should be undertaken in accordance with BS3998:2010 by a competent

tree contractor to ensure that cuts are performed correctly, and positioned so as to avoid

future structural defects or physiological issues, facilitate growth and maintain aesthetic

value.

6.4 Mitigation Planting

6.4.1 As part of the proposals, a scheme of soft landscape treatment has been prepared to

ensure that the proposed development is set within a robust, high quality landscape

setting and that an appropriate transition between the proposals and the wider

landscape context is created.

6.4.2 The proposed landscape scheme seeks to provide a significant number of trees

across the development site and reinforce the existing vegetation associated with the

site’s boundaries. The numbers of new trees being proposed will more than make up

for the relatively small number of individual tree losses incurred within the detailed

and outline areas of the supplication.

6.4.3 The proposed tree planting will incorporate a range of sizes to ensure a varied, high

quality and successful scheme is achieved. Native species will be focused around

the perimeters of the site and within the natural and semi-natural greenspaces. Within

the built environment the use of ornamental species will create a high quality

landscaped setting which complements the proposed built form.



15

6.5 Construction Mitigation

6.5.1 Protective Barriers: Pursuant to the Councils’ advice, it will be necessary to protect

the above and below ground structures of retained offsite boundary tree cover from

damage during construction.

6.5.2 To achieve this, the barrier specification for direct protection should consist of the

default specification provided in BS5837:2012 (shown below). It is considered

essential that barriers are erected prior to occupation of the site for construction

related purposes.

Plate.1 Default Protective Barrier Specification

6.5.3 The siting of tree protection barriers is illustrated within appendix D, which in all

instances is considered to be practicable without conflicting with construction if

located either on the edge of the RPA or the canopy extents (whichever is the

greater). Where proposed access is required with RPA’s (see below), any activity will

be undertaken in the presence of a supervising arboriculturist and barrier positions



16

can be repositioned appropriately as part of this brief. The position for the relocated

barriers is illustrated within Appendix E with a yellow dotted line.

6.5.4 It would be prudent for the project arboriculturalist to oversee the initial erection of

tree protection barriers and provide written confirmation to CBC’s arboricultural officer

once barrier erection is complete.

6.5.5 Proposed Hard Surfaces: The introduction of a pedestrian footpath is proposed

within the RPA of T22 English Oak (c.11% of the RPA). This area is currently under

hard surface.

6.5.6 A precautionary approach to managing the incursion will be to incorporate the design

recommendations listed in 7.4.2 of BS5837:2012, i.e. the preclusion of excavation

into soil, avoidance of localised compaction, and maintained permeability. This can be

achieved if the path is founded on 75mm Standard Cell CellWeb® overlain by a

permeable tarmac wearing course (i.e. TarmacDry®) with non-invasive retaining

edges. Arboricultural supervision during these works is strongly recommended.

6.5.7 The extent of the incursion (detailed above) is considered reasonable, particularly

where exchanged for the existing hard surface. To ensure confidence in the trees

tolerances towards proposed no-dig incursions and to overcome any existing

compaction within RPAs, it is strongly recommended that the full RPA (where on site)

were to be Terravented incorporating a Mychorizial Fungi and Bio stimulant injection.

This work should be undertaken prior to the laying of the cellweb sub-base.

6.5.8 Supervised excavations: The introduction of a road and car parking provision is

proposed within the RPA of T1 English Oak (c.10% of the RPA), T22 English Oak

(c.4% of the RPA), T25 English Oak (.c 3% of the RPA) and T30 English Oak (c.7%

of the RPA). In addition a proposed building is proposed within the RPA of T33

English Oak (<1% of the RPA) and T34 English Oak (c.2% of the RPA).

6.5.9 As a precaution against avoidable disturbance to the RPAs, including damage to tree

root structures it is recommended that the installation of all the features listed above

adopt advice provided in section 7.2 of BS5837:2012 under the heading ‘Avoiding

Physical Damage to Tree Roots during Demolition or Construction’.

6.5.10 In the case of hard surfaces, an arboricultural watching brief and the adoption of the

procedures for manual excavation should be combined with the siting of barriers



17

500mm back from the proposed kerb routes to enable sufficient working room. Where

proposed built forms are to be constructed within RPAs, the working room should be

increased to c.2m.

6.5.11 Ground Boarding: Where barriers are to be offset from proposed built forms, the

intermediate area of exposed RPA will need to be protected during construction by

ground boarding as a precaution against localised ground compaction. It is

recommended that ground protection used is to consist of polyethylene trackmats, the

locations of which are illustrated in Appendix E with a light blue hatch.

6.5.12 Phasing and Services: At this stage, Aspect has not been able to assess the

influence of all proposed services, levels, or provided input regarding the phasing of

construction works as part of the application put forward. Pending the acceptability of

the scale and nature of the proposed development to Crawley District Council it is

anticipated that these details will be the subject of a condition i.e. the focus of an

Arboricultural Method Statement and detailed Tree Protection Plan.

6.6 Future Pressure

6.6.1 Tolerance to trees is a subjective matter and seasonably variable, therefore it is

reasonable to presume that potential occupiers will factor the presence of retained

trees and hedgerows as a major feature of the development when deciding whether

to commit to living within close proximity to them. To alleviate any potential concerns,

it is considered that the TPO is an appropriate control measure to prevent

unsympathetic pruning.



18

7 CONCLUSIONS

7.1 In accordance with the adopted policies of Crawley District Council in the context of

proposed development, a BS5837:2012 survey and assessment has been prepared to

inform the retention of important trees and their contribution to amenity.

7.2 The application demonstrates consideration for all trees within influence of the proposed

design and accommodates the majority of trees considered important to the amenity of

the existing (and proposed) site. In addition, the long-term integration of significant trees

and groups is considered practicable subject to temporary protection during construction

and mitigation for permanent development within RPAs. As part of the design process the

retention of all the significant trees subject to the TPO has also been facilitated.

7.3 Regardless of poor quality trees that should be removed irrespective of development, the

proposals incur the necessary removal of 18no. trees and 1no. group. The impact of these

removals is considered to be acceptable through confident, long-term, integration of

appropriate tree cover, alongside opportunities to provide diverse mitigation.

7.4 Replacement tree planting is expected to increase the canopy area of the site, whilst

enhancing the long-term amenity potential of the site’s overall tree stock.

7.5 In the absence of long-term harm to important trees scheduled within a TPO in particular,

it is our professional opinion that the proposals put forward by BDW Southern Counties

Ltd. allow for technical confidence in the long-term viability of retained and appropriate

tree cover. The proposals are therefore considered supportable from the arboricultural

perspective and in terms of Local Plan Policy and Saved Policywhere it relates to trees.

This opinion is subject to the provision of replacement tree cover, and the adoption of

future safeguards as identified within this document.



19

8 RECOMMENDATIONS (future work)

8.1 A detailed Arboricultural Method Statement could be required by Condition and

subsequently prepared which expands on appendix E.

8.2 Heads of Terms for the Method Statement are advised to include: specifications for tree

protection barriers, including revisions to barrier locations; a schedule of tree works; a

procedure for above soil installations, hard surface removal and excavations within RPAs;

phasing of work; and a scheme for auditing tree protection and subsequent reporting to

the LPA should feature explicitly throughout.

8.3 Detailed Tree Protection Drawings should be prepared to 1:200 scale to support the AMS,

with detail given of proposed levels and service routes.

PREPARED BY:

Dr Richard Curtis Bsc (Hons) PgDip PhD MArborA

Senior Arboricultural Consultant

E: [email protected]

T: 01295 276066

mailto:[email protected]


Arboricultural Impact Assessment 8842_AIA.001

APPENDICES



APPENDIX A

SURVEY BOUNDARY PLAN (8842 SBP 01)



APPENDIX B

TREE SURVEY SCHEDULE (8842 TS 01)

8842 TS 01

BS 5837:2012 Tree Schedule: Ifield Community College, Crawley

BS5837:2012 Tree Survey: Explanation of Survey Criteria

The following survey should not be interpreted as a report on tree health and safety. Aspect’s opinion of tree condition and structural potential is valid for a limited period of 12 months from the date of inspection. Validity is assumed in the absence of inclement weather and no change to the trees existing setting.

Project: 8842 Ifield College, Crawley Survey Date: 07 July 2014

Surveyor: James Bardey & Jamie Pratt

Tree Number

Common Species Name

Trunk Diameter

(mm)

Height (m)

Crown Spread (m) Crown Clearance

(m) Life Stage Physiological

Condition Structural Condition Comments BS5837

Category

RPA Radius

(m) N E S W radial

Area around tree deemed to contain sufficient roots and rooting

volume to maintain the tree’s viability, and where the protection of

roots and soil structure is a priority.

Sequential reference number cited

on all aspect drawing.

Height of first significant branch and/or

canopy

e.g.: young, semi-mature, early-mature,

mature or over-mature

e.g.: above-average, average,

below average or dead

e.g.: good, indifferent, poor, or hazardous

Height and Crown spread measured to the nearest half

meter; # denotes where this is estimated.

Measured to the nearest 10mm; # denotes

estimated diameter where access is not

possible.

Category prefix A-C denotes arboricultural quality, decreasing

from A (high) to C (low); Subcategories 1, 2 and 3 highlight

associated arboricultural (1), landscape (2) and ecological (3)

qualities.

Category U trees are those in such a condition that they

cannot be retained as living trees in the current context for

General observations, i.e. defects, preliminary

management recommendation, presence of

pests/disease, perceived significance.

BS5837:2012 Tree Schedule Ifield Community College, Crawley

N E S W radial

1 English Oak 1100 21 14 (NE) 11.5 10 11.5 4.5 Mature Average Good

Stout stemVery large buttress root to South Maintains single leader for majority of height Even primary branch distribution Previously crown lifted and thinned Structure typical for speciesConsidered to be of high arboricultural quality and value

A12 13.2

2 English Oak 900# 15 8.5 5 Mature Dead Poor Standing deadwood U N/A

3 Common Lime 250 6 3 0.5 Early Mature Average Indifferent Structure typical for species Hard surface within RPA C12 3.0



6 Common Lime 270 6.5 3 0.5 Early Mature Average Indifferent Structure typical for species Hard surface within RPA C12 3.3

7 Common Lime 270 6.5 3 0.5 Early Mature Average Indifferent

Structure typical for species Hard surface within RPACohesive canopies Fork bark inclusion

C12 3.3


Structure typical for species Hard surface within RPACohesive canopiesFork bark inclusion

C12 3.0


Structure typical for species Hard surface within RPACohesive canopies Spoil to East Fork bark inclusion

C12 3.0

10 Common Lime 350 8 4.5 0.5 Early Mature Average Indifferent Structure typical for species Hard surface within RPALarge structural surface roots visable

C12 4.2

11 Common Lime 290 9.5 3.5 0.5 Early Mature Average Indifferent Structure typical for species Hard surface within RPACohesive canopies

C12 3.6


C12 3.6


C12 3.0

14 Silver Birch 170 6.5 2 1.75 Early Mature Average Indifferent C12 2.115 Bird Cherry 410 6 4.5 2 Mature Below Average Poor C12 4.8

16 Apple 17090 3 3 1.75 Early Mature Average Poor C12 2.1

17 Apple 130170 3 3

1.75

Early Mature Average Poor

Stout stem forking at approx 500mmPrimary limbs crossing Union decayedConsidered to be of reduced future potential

U N/A

18 Apple 200160 4 3.8 1.5 Early Mature Average Poor

Oringinally 3 codominant stems only 2 remainForking at approx 500mmDecay in unionConsidered to be of reduced future potential

U N/A

19 Common Ash 420440 13 7.25 7 6.5 7 2.5 Mature Average Indifferent

Folking at approx 1m Co-dominant stemMinor impact wound to North at 1.25m Upper canopy structure is typical for species Considered moderate arboricultural quality and value

B12 7.2

RPA Radius

(m)

Crown

Clearance (m)Life Stage

Physiological

Condition

Structural

ConditionComments

Tree

Number

Common Species

NameHeight (m)

Trunk

Diameter

(mm)

Crown Spread (m)BS5837

Category

Tree Survey Schedule: 7 July 2014


N E S W radial

RPA Radius

(m)

Crown


Physiological

Condition

Structural

ConditionComments

Tree

Number

Common Species

NameHeight (m)

Trunk

Diameter

(mm)


Category

20 English Oak 980 13 5.5 9 8 7 3.25 Mature Below Average Poor

Possible hollow buttress roots Significant basal decayCrown tip die-back Considered to be of reduced future potential

U N/A

21 English Oak 830 18 6.5 5.5 7.2 7.5 4 Mature Below Average Poor

Maintains single leaderCollybia fusipes (Spindle shank) fungal brackets located at mulitple positions at base of stem and structural root flares - root decaying Crown tips dieback likely caused by root decay fungal infectionAbove average epicormic growth throughout stem and crown Terminal decline Considered to be of reduced future potential

U N/A

22 English Oak 930 15 7.75 8.5 13 7 2 Mature Average Indifferent C12 11.1

23 English Oak 1000# 15.5 9.25 9.11 9# 9.5 3.25 Mature Average Moderate

Off-site Single stemMaintains single leaderStructure typical for species Hazard beam failure to North at 4.5m

B12 12.0

24 English Oak 650# 14# 8 8 4.5# 4.5# 3 Mature Average Indifferent C12 7.8

25 English Oak 1110 19 12.8 6.25 9 9 4.5 Mature Average Good

Complete structural limb tear out wound at 10mTypical branch distributionDeadwood to East Considered to be of high arboricultural quality and value

A12 13.2

26 English Oak 1000# 21 9 11 6.5 6.5 3.5 Mature Average Good

Off-site Single stem Obscurred by Ivy Forking at 4mUnable to inspect - restricted access Possible heavy weight loading on lower limbs to South and West

A12 12.0

27 Silver Birch 320 11.5 4 2.5 Early Mature Average Indifferent C12 3.928 Purple Plum 470 6.5 4 2 Mature Average Indifferent C12 5.729 Weeping Willow 620 7.5 7.75 5 6 6.8 3.5 Mature Average Indifferent C12 7.5

30 English Oak 1230 21 8 9.5 12 9.5 4 Mature Average Good

Signifcant buttress rootsPreviously thinnedSlightly above average deadwood Considered to be of high arboricultural quality and value

A12 14.7

31 Common Lime480360410

12 6.75 7.75 7 5.5 3 Mature Average Poor

Above average epicormic growth Structure typical for species Considered moderate aboricultural quality and value Filters views external to site

B2 8.7

32 Silver Birch 330 12 3.75 3 Early Mature Average Indifferent C12 3.9

33 English Oak 600# 13 5.5 4 Mature Average Indifferent

Off-site Obscurred by Ivy Structure typical for species Dimesions estimated - restricted access Considered to be of moderate arboricultural quality and value

B2 7.2

34 English Oak 800# 15 6 4 Mature Average Indifferent

Off-site Obscurred by Ivy Previously reduced Structure typical for species Dimesions estimated - restricted access Considered to be of moderate arboricultural quality and value

B2 9.6



N E S W radial

RPA Radius

(m)

Crown


Physiological

Condition

Structural

ConditionComments

Tree

Number

Common Species

NameHeight (m)

Trunk

Diameter

(mm)


Category

G1 Common AshCherry 110 max 5 2.5 1.75 Young Average Poor Upper crown structure typical for species

Multi-stemmed from base C12 1.2

G2

Silver Birch Sycamore PlumEnglish OakElder

300 max 11 max 6 max 2.5 Young - Early Mature Average Indifferent

Off-site beltStructure typical for species Provides screening

C12 3.6

G3 Lawson cypress 100# 4 1 0.5 Young - Early Mature Average Indifferent

Off-siteUnmaintained garden hedge Intermittent

C12 1.2

G4 Ash hedge Horse chesnut 500 7--9 3.5-6 0.75-1.75 Young - Early

Mature Average Indifferent Off-site Hedge formaly maintained now neglected Structure typical for species

C12 6

H1 Common HawthornHazel 100 max 2.5 1 0.5 Young Average Indifferent Structure typical for species

Maintained hedgerow C12 1.2




APPENDIX C

TREE PRESERVATION ORDER (Plan No. P1501/96)



APPENDIX D

TREE CONSTRAINTS PLAN (8842 TCP 01)

1(TPO:T14)

[2] (TPO:T13)

3

4

5

6

7

8 9

10

11

12

13

14

15

16

[17][18]

19 (TPO:T18)[20] (TPO:T19)

[21] (TPO:T20)

23 (TPO:T22)

2728

29

30 (TPO:T12)

31

32

22 (TPO:T21)

24 (TPO:T23)

G1

G2

G3

H1

H1

25 (TPO:T11)

26 (TPO:T10)

33

34

G4

G3

Horse Chestnut

T30: Approximately. 11% of RPA underrecent development including excavatedarea south of building footprint. Proposalsto provide an area equivalent to theincursion contiguous to the remaining RPA.

T27-T29 (TPO:G5 remnants)

Tree Constraints Plan

MAY 2015

8842 TCP 01 Rev B

DATE

DRAWING NUMBER REVISION

CLIENT

TITLE

Based on topographical dwg no. Topographical Survey 20140707.dwg

REVISIONS

SCALE

1:1000 @ A3 GWDRAWN

KEY:

Tree Numbers

Category 'A' RPA

Ifield College Crawley

Barratt Homes

Tree Canopies

Chk'dDrawnNOTEDATEREV

15

[8]

Category 'B' RPA

Category 'C' RPA

Category 'U' Trees

0m 40m10m 20m1:1000 @ A3

Shading Arc

Cited from Google Earth

Note: T32,T33,T34,G1,G2,G3 and H1 are not onthe topographical survey and their locations areapproximated using scale aerial photographs andby taking measurements onsite.

Regenerative scrub present on entire site. Speciesinclude Goat Willow, Silver Birch, Buddlieja, Elm,Elder, English Oak, Sycamore and Ash. Below thethreshold for the British Standard. Height 6mmaximum. Average DBH = 50mm.

RCGWTPO reference added03.11.14A

B

RCGWUpdate to hatching27.05.15B



APPENDIX E

TREE PROTECTION PLAN (8842 TPP 01)

[17][18]

[20] (TPO:T19)

[21] (TPO:T20)

[2] (TPO:T13)

1(TPO:T14)

19 (TPO:T18)

23 (TPO:T22)

30 (TPO:T12)

22 (TPO:T21)

24 (TPO:T23)

25 (TPO:T11)

26 (TPO:T10)

T27-T29 (TPO:G5 remnants)

3

4

5

6

7

8 9

10

11

12

13

14

15

16

2728

29

31

32

G1

G2

G3

H1

H1

33

34

G4

G3

Horse Chestnut

G2 target pruned back 4m toallow sufficient clearance forproposed parking spaces andconstruction room.

T1: Areas of proposed hard surface within RPA tobe manually excavated under direct arboriculturalsupervision. Tree protection barriers to be relocatedto secondary position post construction.

G4

T22: Areas of proposed hard surfacewithin RPA to be constructed above soil.Tree protection barriers to be relocatedto secondary position post construction.

T30: Proposed area of road within RPA to bemanually excavated under direct arboriculturalsupervision. Tree protection barriers to berelocated to secondary position post construction.

Proposed parking spaces to utiliseexisting hard surface footprint.

H1: Clearance required to provideconstruction room. Restockedfollowing construction. Extent ofremoval to be determined onsite byproject arboriculturalist.

T25: Areas of proposed hard surfaceand building footprint within RPA tobe manually excavated under directarboricultural supervision.

T23: Ground boarding to be positionedbetween proposed building footprint andtree protection barriers.

T31: Ground boarding to bepositioned between proposed buildingfootprint and tree protection barriers.

H1: Removal of c.5m to accommodateproposed pedestrian access.

T33 & T34: Area of proposed building footprint withinRPA to be manually excavated under directarboricultural supervision. Tree protection barriers tobe relocated to secondary position during construction.

T33 & T34: Ground boarding to bepositioned between proposed buildingfootprint and secondary barrier position.

T22: Areas of proposed road and parkingwithin RPA to be manually excavatedunder direct arboricultural supervision.

T25: Ground boarding to bepositioned between proposed buildingfootprint and tree protection barriers.

H1 target pruned back toallow sufficient clearance forproposed parking spaces andconstruction room.

H1 target pruned back toallow sufficient clearance forconstruction room.

Tree Protection Plan

MAY 2015

8842 TPP 01

DATE

DRAWING NUMBER REVISION

CLIENT

TITLE

Based on layout ref: 081006-BAR-SC-01-PRELIM-14.05.15.dwg

REVISIONS

SCALE

1:1000 @ A3 GWDRAWN

KEY:

Tree Numbers

Category 'A' RPA

Ifield College Crawley

Barratt Homes

Tree Canopies

Chk'dDrawnNOTEDATEREV

Tree Protection Barrier

15

[8]

Category 'B' RPA

Category 'C' RPA

Category 'U' Trees

0m 40m10m 20m1:1000 @ A3

Key1 Standard scaffold poles2 Heavy gauge 2m tall galvanized tube and welded mesh infill panels3 Panels secured to uprights and cross-members with wire ties4 Ground level5 Uprights driven into the ground until secure (minimum depth 0.6m)6 Standard scaffold clamps

Default Barrier Specification, cited BS 5837:2012

Tree Protection Barrier(2nd Position)

Cited from Google Earth

Note: T32,T33,T34,G1,G2,G3 and H1 are not onthe topographical survey and their locations areapproximated using scale aerial photographs andby taking measurements onsite.

Trees to be Removed

Manual Excavation

Above Soil Surfacing

7

Ground Boarding



APPENDIX F

TREE SURVEY METHODOLOGY

Ifield Community College, Crawley May 2015

Tree Survey Methodology 8842_TSM.001

May 2015

Tree Survey Methodology

The tree survey is a form of Visual Tree Assessment undertaken by a competent and qualified

arboriculturist on 9th December 2014 during cold and clear conditions. Tree locations are

identified via a topographical survey; locations of any trees excluded from the topographical

survey were plotted on site. The purpose of the survey is to record information about trees on

or adjacent to the site to inform design options. In keeping with clause 4.4 of BS5837: 2012

‘Trees in Relation to Design, Construction and Demolition’, the survey provides a record of the

following parameters:

Tree Numbers: all individual trees are sequentially numbered. Groups of trees, woodlands and

hedgerow are also sequentially numbered with a corresponding prefix relevant to their type

e.g. G, W or H respectively; the identification of trees as woodland, groups of trees or within

hedgerows is undertaken where appropriate. The identification of trees as individuals within

collections has been made where it is considered sensible to make such a differentiation.

Species: listed by common name

Stem Diameter: given in millimetres and obtained by measuring single/multiple stems at

1.5m using a diameter tape in accordance with Annex C within BS5837:2012. Diameters of

inaccessible trunks are estimated and provided with the suffix ‘#’.

Tree Heights: determined using a clinometer and measured to the nearest 500mm. Heights

are estimated where specific triangulation is not achievable and by reference to measured

trees nearby (provided with the suffix ‘#’).

Crown Spreads: measured at cardinal points using a Leica DistoTM laser distance measurer.

Measurements were recorded to the nearest 250mm. Inaccessible crown spreads are

estimated based on measured canopies nearby and provided with the suffix ‘#’

Crown Clearance: The height of the first significant living branch and/or canopy (as

appropriate) is recorded using a Leica DistoTM laser distance measurer to inform vertical

ground clearance. Crown clearance may be higher or lower than the first significant branch.

Estimated clearances are provided with the suffix ‘#’. Height of first significant branch will be

provided where considered advantageous to make the distinction.


Tree Survey Methodology 8842_TSM.001

May 2015

Life Stage – The age of trees, groups of trees, hedges and woodlands are defined as follows:

Young (within the first 1/4th of life expectancy)

Semi-mature (within the second 1/4th of life expectancy)

Early Mature (within the third 1/4th of life expectancy)

Mature (within the fourth 1/4th of life expectancy)

Over Mature and Veteran (exceeding normal life expectancy)

Veteran (significantly exceeding normal life expectancy)

Physiological and structural condition: physiological condition defined as follows; good, above

average, average, below average, poor or dead. Structural condition is defined as: good,

moderate, indifferent, poor or hazardous

Comments: further observations were recorded where necessary i.e. details regarding defects,

preliminary management recommendations, presence of pest/disease and perceived

significance.

BS5837 Category: pursuant to BS5837:2012 section 4.5 and cascade chart for tree quality

assessment (refer to reproduced Table 1 overleaf). Trees qualifying under a given category (A-

C and U) and any appropriate subheading (1-3) are considered to fall within the scope of that

category’s definition.

Estimated Remaining Contribution. Described` as a guideline only and in terms of years: <10,

10+, 20+ and 40+ relevant to category U, C, B and A respectively. This information is not

provided on the tree schedule to avoid conclusions based upon ‘life expectancy’.


Arboricultural Impact Assessment 8842_ AIA.001

May 2015

Documents

PROPOSED RESIDENTIAL DEVELOPMENT IFIELD COMMUNITY COLLEGE ... · PROPOSED RESIDENTIAL DEVELOPMENT IFIELD COMMUNITY COLLEGE CRAWLEY ... planning application for residential development