Buckden Road - Brampton

BACKGROUND
The site is located opposite the entrance to RAF Brampton, near Huntingdon and was used partly as a vehicle testing site, partly as an industrial site, with some existing housing to the front. There was considerable ground contamination and waste materials had been stored in mounds against existing trees.

ACD Landscape Architects were commissioned by Woods Hardwick, on behalf of Twigden Homes, in the summer of 1997, to carry out an initial appraisal of the existing trees on the site. We subsequently carried out a detailed survey and prepared a Tree Report in December 1997.

Considerable negotiation was held with David Evans, the Huntingdon DC Tree Officer, firstly over the damage inflicted on existing trees by the industrial waste and subsequently over the viability of retaining trees within the development and the suitability of two over mature trees that were landscape features at the entrance to the site.

Once the layout was agreed, ACD prepared detailed Landscape Proposals for the site and prepared a Schedule ofWorks for the retained trees, again in consultation with David Evans.

DESIGN REVIEW
The site layout was based on a range of detached houses that Twigden Homes proposed, at a pre-PPG3 density, with the constraints of the entrance location and the trees agreed for retention with the Huntingdon District Council.

Some trees were retained in private gardens, others to frontages, most survived and still provide the landscape feature after eight years, with the newly planted shrub, tree and hedge scheme now maturing to provide a good landscape setting to the houses.

Our greatest concern was the retention of the Sweet Chestnut T25 and the Wellingtonia T40, both identified in the Tree Survey as over mature and with structural faults. The Sweet Chestnut particularly had major internal decay and, despite its’ obvious landscape and amenity value, was a doubt for retention in a prominent entrance location.

The tree has survived eight years and despite continuing to decline slowly, it has good natural vigour and provides a feature. Providing it is periodically checked, there is no reason why it cannot remain a feature of the scheme for some time and then be replaced. One regret is the failure to ensure that the footpath was not constructed to a ‘no-dig’ detail as had been proposed.

The Wellingtonia was accepted by the LPA as of inferior quality and limited life expectancy and to this end, another Wellingtonia was specified in an adjacent location, to provide a future replacement landscape feature for the site frontage.

The retention of the Ash T22 was the subject of the greatest debate with officers, as it had been adversely impacted by the previous site use and deposition of waste materials, but was agreed by all to be a good landscape feature. Significant tree surgery was carried out to improve the form of the tree and ensure that there was no conflict with plot 17 and, whilst it obviously dominates the house frontage, it has adapted well and actually developed in form. It provides a pleasing and mature setting to the development.

The landscape planting throughout the scheme has developed well and been supplemented by owners. There was a second phase to the development which ACD was also responsible for, but this had few of the constraint issues that Phase 1 had presented!

CONCLUSION
How long do trees need to survive to justify retention? Three years? Thirty? It is a difficult question to answer, but a constant challenge on development sites where the trees suffer first the likelihood of construction impact and then future pressure from residents who decide they don’t quite like them as much as they thought when they first moved in.

BS 5837:2005 Trees in Relation to Construction bases much on the life expectancy when assessing Categories of trees and yet the BS has always cautioned against inappropriate retention which might result in future problems as trees fail and become a Health and Safety hazard.

The Brampton scheme is perhaps an example of good fortune, in that over-mature trees have survived despite their structural faults, continuing to provide landscape amenity and trees that have a demonstrable impact on residents private amenity have been tolerated and accepted as landscape features. On this second point, it is important to remember that the LPA must be seen to be ‘reasonable’ in refusing permission to fell or carry out reduction works to trees covered by Tree Preservation Order or subject to a Planning Permission.

In this instance, significant time was spent on negotiation with the Council officers and, notwithstanding the inevitable decline of the over-mature Wellingtonia and Sweet Chestnut, the scheme can be considered a success. The retention of existing landscape features, the provision for their long-term replacement with new trees and the maturing shrub and hedge scheme which provides the landscape setting for the housing, all ensure that the scheme will continue to develop long after the designers have archived the development plans!

More information to follow