Appeal 6003720

The appeal is dismissed.

An application for costs was made by the appellant against the Council and is the subject of a separate decision.

The main issue is the effect of the appeal proposal upon the longevity of a number of protected trees and their contribution to the character and appearance of the area.

The appeal site is located within a residential area that is verdant in character. There are 6no mature [name] trees within the frontage of the appeal site which are protected by a Tree Preservation Order and provide both interest and quality to the street scene.

The proposed access and gateway would be to the western end of the front boundary, beyond which are the pine trees which all appear to be in good health. Those trees identified as T1 – T4 within the submitted Arboricultural Implications Assessment and [name] (AIA) are categorised as B1 & B2 and have a decent level of life expectancy, I have been given no substantive reason to come to a different conclusion on this.

The ground around the trees where the driveway would be laid is uneven (largely due to tree roots) and also slopes gently down towards the southwest corner of the site where a pedestrian gate and path currently exists. Paragraph 3.2.1 of the AIA states that no changes to soil levels within the root protection areas (RPA) of the retained trees would be made. However, that is in conflict with the appellant’s own [name] which states that where tree roots are exposed the ground will be levelled and it is quite clear to me that some degree of levelling would need to take place in order to install a no-dig cellular confinement system. Indeed geocell mats need to be laid on level surfaces, so sloping or uneven ground can be challenging.

BS5837:2012 advises that that no excavation, soil level change, or compaction should occur within RPAs unless absolutely necessary and also states that where alterations to soil level within RPAs are unavoidable, solutions such as no-dig surfacing or engineered systems that maintain aeration and drainage must be considered. However no topographical data or cross-sections have been provided that identify the degree of fill that would be required to provide a level surface nor mention of compaction or implications of loading upon tree roots.

The Arboricultural Association’s (AA) ‘The Use of [name]: A Guide to [name] (2020) states that whilst the use of above-ground geocells to install surfacing near trees have been employed in the UK for over 20 years, their use is not always a simple matter and the limitations of the approach are often misunderstood. Also, very few research studies have been conducted regarding the long-term effects of installing such surfaces on soil structure and on the health of adjacent trees.

The AA’s guide goes on to state that the basic approach of using a cellular confinement system over tree root zones can be prescribed by an arboriculturist, but in order to guarantee that the surface will be suitably durable, the final specification should be produced or approved by a civil engineer. It also states that it may be inappropriate for a cellular confinement system to be used in a root protection area when it would be one of several impacts on a tree to be retained, such that the cumulative effect might be considered to be detrimental. Bearing in mind that the RPAs of trees T1 and T2 have already been impinged by the garage of the host dwelling, and the existing driveway impinges upon trees T2 and T3 the cumulative effects upon these trees has not been adequately assessed.

In addition, contrary to AIA paragraph 3.3.2, the protective fencing would not prevent construction vehicles from encroaching on to the RPAs and in respect of paragraph 1.5.5 of its method statement, to erroneously remove roots without assessment of their size and condition could also have dire consequences for the long-term health of the trees. This is notwithstanding that the appellant’s own method statement stipulates that no roots would be cut.

I consider that it would not be appropriate to impose a condition requiring further details to be provided, as ultimately a ‘no-dig’ solution might not be feasible, and as it stands I am not convinced that the scheme would protect the long-term health of these trees.

I have the utmost respect for the appellant’s reasoning behind the proposal and it is quite clearly unfortunate that their vehicle was blocked in by a neighbour’s visitor when they were attempting to travel to the hospital in an emergency situation. The ‘human factor’ is a material consideration in the determination of this appeal, however the occupation of dwellings is ultimately transitory in nature and I consider that the reasoning does not provide an overriding justification for the proposal before me, but if a private drive is blocked, that is a civil matter beyond the remit of the planning system.

I can understand the appellant’s frustration with regard to the fact that the Council accepted his previous arboricultural submissions, however for the reasons I have given the impacts of the proposal upon the [name] trees cannot be adequately assessed. [name] note reference to the deemed ‘Avala’ precedent, ultimately each case must be assessed on its own merits. On the matter of the gate posts alone, if I had been satisfied with the detail associated with the surfacing works, a condition requiring on-site supervision of the installation of the eastern-most post could have been imposed as it is shown to be only just inside of the RPA of tree T3.

I conclude that in view of conflicting claims with regard to the severing of tree roots and with no information on how much fill would be required to level the site prior to the laying of the cellular confinement system, that the effects of the additional compaction and weight upon the RPAs cannot be ascertained. Therefore, taking a precautionary approach, in order to ensure the longevity of the TPO trees, and having regard to the physical constraints already imposed by the garage and driveway serving the host dwelling, I consider the scheme to be unacceptable; and the harm is not outweighed by the benefits of it advanced by the appellant.

The proposal could have dire consequences for the long-term health of the trees, the loss of which would have a detrimental effect upon the character and appearance of the area. Consequently, I find the proposal contrary to Policy CP9 of the South Bucks Local Development Framework Core Strategy Development Plan Document adopted February 2011 and Policy L10 of the South Bucks District Local Plan adopted March 1999 which together require landscape characteristics and biodiversity resources within [name] to be conserved and enhanced by, amongst other things, not permitting new development that would harm landscape character, unless the importance of development outweighs the harm caused, and stipulates that proposals for tree works that would negate the objectives of a Tree Preservation Order or otherwise damage the public amenity of trees or their contribution to the character of the locality will not be granted consent, except where specialist circumstances can be demonstrated and acceptable alternative planning and management proposals are agreed.

Having regard to the above and all other matters raised, I conclude that the appeal be dismissed.