OTISS now supports several tree valuation methodologies. These can be used as part of a TreeSafety, Risk Assessment or BS5837 survey; or used to carry out tree stock valuation on an estate. As part of each tree inspection, you fill in the valuation factors which are used to automatically calculate a resulting monetary value (£) or merit score.

  • CAVAT – Capital Asset Valuation of Amenity Trees developed by Chris Neilan and the LTOA.
  • TEMPO – Tree Evaluation Method for Preservation Orders developed by Julian Forbes-Laird.
  • (under investigation) Helliwell – Visual Amenity Valuation developed by R Helliwell.

Tree Valuation is an extra option which can be purchased alongside your current subscription. See the What does it cost? webpage for details. Existing users should contact sales if they would like a 30day free trial of this new feature.

These methodologies are simply an extra part of a normal OTISS TreeSafety/BS5837 survey. The tree valuation is simply part of the data that is downloaded and sync’ed with the other inspection data and photos.

NB: by default, the Tree Valuation methodologies are hidden on the survey forms. Use the Customize Survey webpage to make them visible. Typically only one valuation method would be used at any one time.

All these tree valuation methodologies are presented in a similar way.

  • The tree valuation sub-forms are accessed via buttons at the bottom of the survey form on the mobile apps, or as separate tabs on the web based survey form.
  • These forms/tabs allow you to enter the valuation factors and shows the calculated resulting monetary value (£) or merit score.
  • Each tree valuation method has a field on the Customize Survey webpage that allows you to change the status to Mandatory, Visible or Hidden.
  • The results can be viewed on the TreeSafety/BS5837 spreadsheet page – the columns are at the right hand end.
  • There is a special purpose Excel report for each tree valuation method. In addition, the results can be found in the Excel ‘complete’ report and you can also include the results in Excel reports when you tailor your own reports using Excel Report Templates.

Each method is described in further detail below.

CAVAT

CAVAT provides a method for managing trees as public assets rather than liabilities. It is designed not only to be a strategic tool and aid to decision-making in relation to the tree stock as a whole, but also to be applicable to individual cases, where the value of a single tree needs to be expressed in monetary terms. Capital Asset Valuation of Amenity Trees (CAVAT) was developed by Chris Neilan and the London Tree Officers Association (LTOA) in 2008 and is regarded as one of the principal methods of tree valuation in the UK.

The main source of information about CAVAT is on the London Tree Officers Association website. Please refer to that website regarding all questions of training, guidance and suitability.

Using CAVAT on OTISS:-

  • OTISS supports both the CAVAT Full and Quick methods as specified in June 2018. You can swap between the two methods at any time on the CAVAT survey form.
  • The CAVAT method can be customised as Mandatory, Visible or Hidden as part of a TreeSafety/BS5837 survey. In addition you can pre-select which method to use by putting the word ‘Full’ or ‘Quick’ in the ‘Initial Value’ field on the CAVAT custom field.
  • The CTI factor and Unit Value can be configured for each site/survey by editing the TreeSafety/BS5837 survey form. These values apply to all tree inspections for that survey. This means that over time you can re-survey/re-valuate the tree stock and the OTISS history will store how the value has changed over time.
  • For your convenience, the CAVAT Excel reports have been kept very similar to the standard CAVAT spreadsheets provided by the LTOA.

TEMPO

TEMPO is used as “A systematised assessment tool for TPO suitability.” and is intended for use in the preparation of Tree Preservation Orders (TPOs) for local authorities in the UK. It was developed by Julian Forbes-Laird to assess what attributes a tree should have in order to merit statutory protection by TPO.

The main source of information about TEMPO is on the Forbes-Laird Arboricultural Consultancy (FLAC) Tree Assessment Systems website. Please refer to that website regarding all questions of training, guidance and suitability.

  • OTISS supports the TEMPO-GN method as described in November 2009 in the document published on the FLAC website.
  • The TEMPO method can be customised as Mandatory, Visible or Hidden as part of a TreeSafety/BS5837 survey.
  • A TEMPO survey template and Excel report are provided (when using the OTISS TreeSafety subscription) for projects that are mainly focused on TPO evaluation.

Helliwell

We are currently investigating whether the Helliwell valuation methods can also be included in OTISS…

The Helliwell System was devised by R Helliwell as a means of achieving logical descisions in planning and management of woodlands and urban tree populations. The methodology can be applied to individual trees and to woodlands. In each case the trees’s attributes are ranked on a set of scales and allocated points accordingly. The calculated points can then be converted to a monetary value.

The main source of information about the Helliwell System is on the Arboricultural Association website What is the Helliwell System? and in the published Guidance Note for Helliwell System 2008. Please refer to that website regarding all questions of training, guidance and suitability.