BS5837 Surveys are typically carried out by Arboricultural Consultants as part of the UK planning process. They will visit the site, carry out the inspections and record the results using the BS5837 Survey Android™ application (view screenshots), or the data can be noted down and later entered directly into the BS5837 pages on the OTISS website.

Viewing the BS5837 Data

The BS5837 button shows the trees as rows on a table/spreadsheet. Read more about how to sort and filter the data and edit the data. The spreadsheet can be used to select/filter trees, and then various reports can be created.

The survey form can be customised to suit your own working practice and for each individual client’s requirement – see below.

The table (at bottom of the page) lists the data that is recorded for each tree – it includes all the fields required for a complete BS5837:2012 survey and some additional fields.

BS5837 Spreadsheet

The web page presents the trees as rows on a table/spreadsheet. Read more about how to sort and filter the data and edit the data.


Use the Species fields to assign a genus/species by Common or Botanical name. The Variety field allows for further distinctions to be recorded (if required) – enter some text or select from the configurable dropdown list.

If the Structure is a Group, Hedge, Shrubs or Woodland (displayed as a polygon or a linear oblong), then you can record multiple species with a Variety and NumTrees for each one. The NumTrees for each species are automatically added up and the total stored in the NumTrees field for the group.

OTISS provides several regional lists of tree species (e.g. UK/Europe, Australia, New Zealand, etc.). Each list contains 100s of native and common species for that region. These lists also include entries for the genus (e.g. Willow sp.) for when species level identification is not required. You select the regional list at registration and never need to worry about it again. You cannot add or change these lists – they are shared between all OTISS users.

For each estate, you can build up a list of Estate Tree Species to augment the common species. On the survey forms, the two sets are presented as a single list of species. Use the Estate-> Tree Species website page to configure the species list. New species can also be added when using the OTISS survey apps.

If you find a species that you think should be added to the shared, regional OTISS lists, then please email the details to

When you change the species, the Mature/Ultimate Height field on the More Data tab is updated to show the value suggested in NHBC Chapter 4.2 Building near Trees. You can update this value if required, to reflect the growing conditions on the site.

Tree reference/tag numbers

When you plot a new tree, OTISS ‘suggests’ a suitable reference/tag number to use. But this is only a suggestion – you can change it to whatever you like! There are three different methods for making this suggestion. Choose the one that best suits your requirements.

  1. Arb Standard – T01, G01, H01, T02, T03, G02, …
  2. Arb Single – T01, G02, H03, T04, T05, T06, G07, …
  3. OTISS Flexible – ABC-001, ABC-002, ABC-003, …

Read more about Tree Numbering…


  • Measurements for height and clearance are automatically rounded to the nearest half metre for dimensions up to 10m and the nearest whole metre for dimensions over 10m.
  • Measurements for N, E, S, W crown spread are automatically rounded up to the nearest half metre for dimensions up to 10m and the nearest whole metre for dimensions over 10m. Common practice is use a tape measure or laser to measure from the canopy edge to the bark; the rounding up will then cater for the stem diameter. The recorded values are then assumed to be from the centre of the stem to the canopy edge.
  • Measurements for stem diameters are rounded to the nearest 10mm.
  • Enter negative numbers for estimated measurements – these will be shown as ‘nn#’ on reports.

Stem Diameters & RPA

Recording the stem diameters is an important part of the BS5837 survey. Single or Multiple stem diameters can be entered as a list of numbers separated by commas. Measurements for stem diameters are rounded to the nearest 10mm – as specified in BS5837.

  1. Single stem tree. Enter Num. Stems=1 and Stem Diameters=X.
  2. For a small number of stems where you can measure each one. Enter the Stem Diameters=X,Y,Z (numbers separated by space, comma or dot). The app will update the Num. Stems field.
  3. For coppiced/multi-stem trees where there are too many stems to measure, you must estimate a count and an average. Enter Num. Stems=N and Stem Diameters=Y.

OTISS will automatically calculate the RPA Radius, and draw a circular RPA on the Map. The calculations for combined stem diameter and RPA are as specified in BS5837:2012. For ‘veteran’ trees the RPA is calculated as 15x stem diameter as per the 2017 guidance.

  • For linear hedges, the average stem diameter (not the combined stem diameter) is used to calculate an RPA radius that is applied along both sides of the hedge line.
  • The RPA for a group/polygon of trees is the same as the enclosed area plus a 1 metre buffer.

Users that have the OTISS Premium subscription have the option to Modify the RPA to better suit the tree condition and surrounding area. This is done by first selecting the Modify RPA on map option in the survey form, then using the RPA tool on the Maps page to reshape the RPA – see video below.

  • First, tick ‘Show RPA’ on the BS5837 Options panel. This will show the standard and modified RPAs for the trees and groups.
  • Next, use the Edit tool to bring up the Survey Form for a tree, and select the ‘Modify RPA on map’ option.
  • Optionally, tick the ‘Show Area & Length’ option on the Map Options panel.
  • Finally, you can use the RPA tool to re-shape the RPA polygon.
  • Please note that the RPA Tool is only available with the OTISS Premium subscription. The Standard subscription calculates and draws the BSI standard RPA – but does not allow you to modify it.

Survey Notes…

The Survey Notes, Recommendations and Comments fields allow for free text entry. But to speed up the survey process we provide a means of quickly entering your commonly used sentences and phrases. Below each field there is another button that allows you to select from a list of commonly used sentences and phrases, these are appended to the text field and can then be modified to suit this particular inspection. You can customise this list of commonly used sentences and phrases via the Customise Survey button on the BS5837 page – see below.

The Description field is commonly used to describe the location of the tree and for Risk Assessment, anything that may be a target for tree safety purposes. These details tend not to change between surveys.

The Survey Notes fields are used to describe various aspects about the tree itself – its defects, fungus, pests and diseases, etc.

The Comments field is typically used for notes about the RPA or anything else that may be relevant.

Trees, Groups and Hedges

On the map page, there are separate buttons to allow you to add individual Trees, Hedges (linear), Groups of trees (polygon shape).

BS5837 plan

The Structure field is used to control how an item is displayed (and stored). Individual trees are shown as POINT icons. Groups, Hedges, Shrub and Woodland areas can be shown as either POLYGON or LINE STRING shapes. Simply select a structure and press press Save – the location co-ordinates will be automatically converted to the required shape.

The location coordinates are shown in the standard Well Known Text (WKT) representation for GIS objects. We don’t expect that you will ever need to edit these coordinates directly. It is recommended to change the shape and location on the Map page. Valid WKT formats are as follows:-

  • POINT (x y)
  • LINE STRING(x1 y1, x2 y2, x3 y3, …)
  • POLYGON ((x1 y1, x2 y2, x3 y3, …, x1 y1)) – NB: the last set of coordinates must be the same as the first.

Groups and Un-named Trees

The BSI 5837:2012 does not specify what to do with groups of trees in any great detail. With OTISS, Groups and Hedges can be created by plotting a set of individual trees and then ‘wrapping’ them up to form a single item in your reports. Plotting these internal trees is mainly useful so that you can show their Crown Spread and/or RPA on the plans. But you do not want these extra trees showing up in the reports as un-wanted clutter.

Step 1: Plot the trees within the group (using Add Tree as normal) and partially fill in the Survey Form.

  • Only fill in the information for the Retention Category, Crown Spread and/or the Stem Diameter – or as much as you need to record. None of the other information you fill in will appear on the reports – but it may be useful to make a few notes and photos as required.
  • You can mark the tree as Un-named by setting its Reference to ‘#group’ or anything starting with the letter ‘#’ – there is a dropdown to make this easier. An Un-named tree is one those Reference begins with ‘#’ and is not allocated a normal Tree/Tag number such as T34.
  • As you use the Maps, the #group name appears to make it easier to select the trees. But when you Print or Download the maps, these labels will disappear.
  • Un-named trees will appear on all maps/plans/drawings/CAD/etc, but never appear in the reports or on the spreadsheet page.
  • Adding the first Un-named tree and then using the Replicate tool is a quick way of plotting a group of similar trees.
  • Of course there may be one or two trees within the group that you do want to allocate a Tree No. and fill in all the details in the normal way.

Step 2: A separate Group (polygon) is then drawn around the trees (using Add Group as normal) and complete the Survey Form.

  • Plot and Re-shape the Group’s crown to enclose the above trees.
  • Fill in all the relevant fields for Life Stage, Life Expectancy, Survey Notes, Species, Recommendations, etc. This information is for the entire group and will appear as a single row/item in the reports.
  • In fact, you could do this first and then plot the Un-named trees later if you wish.
  • In fact, for an area of shrubs or where the trees are not very relevant, you can just plot the Group and not bother with any internal or un-named trees.
  • Use the Map Reshape tool to manually reshape the group’s crown by clicking-and-dragging the shape as required.

Step 3: Users with the OTISS Premium subscription have a few extra features.

  • When you select the Map Reshape tool, a small information panel appears at the top of the map with two buttons.
    • You can manually reshape the group’s crown by clicking-and-dragging the shape as required.
    • The Enclose Trees button will re-draw the group outline to enclose/include the crowns for all the named and un-named trees inside the group. If you did not enter a crown spread for a tree – it assumes a 2 metre crown so that the tree remains inside the group.
    • The Expand Crown button will expand and simplify the shape of the crown to make it easier for manual re-shaping.
    • After using the buttons, you can manually reshape the crown further as required.
  • Select the Map RPA tool and a small information panel appears at the top of the map with two buttons.
    • You can manually reshape the group’s RPA by clicking-and-dragging the RPA as required.
    • The Enclose RPAs button will re-draw the RPA to enclose/include all the RPAs of the named and un-named trees within the group’s crown. If you did not enter a stem diameter it assumes there is no RPA needed for that tree and the tree may be outside the group’s RPA.
    • The Revert to Crown button will change the RPA to a shape that gives a 1 metre buffer around the group’s crown.
    • After using the buttons, you can manually reshape the RPA further as required.
  • On website only: Select the Edit tool to edit the group.
    • On the Multiple Species tab, the Update from group trees button will gather the species names and tree counts from the un-named trees within the group. Note – it only checks the un-named trees, because the named trees are already in the reports.
    • Then you can update the species list as required – perhaps there are more trees in the group than you actually plotted.

Map Icon Colours

The colour of the map icons is specified in the BS 5837 standard and cannot be changed. However it is sometimes useful to change the colour of the associated text to make it more readable on some maps.

On the Maps page, use the BS 5837 Options panel to (a) to show the Colour Key/Legend, and (b) the Colour Config button takes you to the BS 5837 Map Colours web page.

The BS 5837 Map Colours web page (also found via the Customise Survey button on the BS5837 page), is used to change the text colours and the Colour key.

On each colour row, you can modify: (a) a Display Text that is shown in the Colour Key; (b) the map colours to use for the text; and (c) the order of the rows in the Colour Key. The icon colours are fixed based on the Retention Category for each tree.


When re-surveying a tree, the most recent ‘Identification’ photo is displayed at the top of the survey form. The Photo icon at the top of the screen shows all the photos for this tree and allows you to take new ones.

Premium BS5837 users can already modify the RPA of trees and groups. Now they have additional buttons to automatically create the crown and RPA of a group so that they neatly enclose the trees within the group.

Survey/Client Templates

OTISS provides a standard BS5837 survey form with all the required fields and a few additional fields that may (or may not) be useful for you. Many people will use our standard survey form, but many users like to customise the survey form (a) to suit their own working practice and preferences, and/or (b) to accommodate a clients’ specific requirements.

We recommend that you setup a survey form that reflects your preferences and use that on all your clients. This is achieved using the ‘Client Templates‘ feature. You can create one or more ‘client templates’. These template ‘clients’ are not used for doing surveys or real projects – they are just an easy/familiar way for setting up and storing your ideal survey forms (and some other settings). Here is what you have to do.

  1. Create a client with a suitable name (e.g. ‘BS Survey #1’).
  2. Select that client and customise it’s Survey Forms to be your ideal ‘standard’ – i.e. customise the field names, picklists of common values, mandatory fields, etc.
  3. Now every time you create a new a client, make sure to select ‘BS Survey #1’ in the Client template field. The survey forms (and other settings) will be copied from the selected template.
  4. If required, the new client’s surveys can be customised further – without changing your template.

As you learn more about using OTISS, you can keep returning to the template client and tweaking it to make improvements. Then subsequent new clients will use your newly improved forms, or you can copy the changes into a specific client using the Survey Templates button as described below.

Customise the Survey Form

Each client has its own survey form which can be adapted to accommodate any specific requirements. Customizing a survey form for one client does not change the survey forms for your other clients. You can customise most of the fields on the survey form via the Customise Survey button on the BS5837 page – i.e. all fields except those field marked with a * in the table below.

Edit each field to customise the following:-

  • Each field has a ‘Field Id’ which is what OTISS uses (internally) to identify each field on the survey form and when generating reports.
  • The field’s ‘name‘ is what actually appears on the survey forms and reports. You can change the Field Name. A shorter name is suitable for columns in tables and spreadsheets, whereas a more informative name can be used on the survey forms.
  • A picklist of common values will speed up data entry on the mobile devices. This can be ‘suggestion’ list where you pick an item from the list but can also entry a value manually; or you can tick the “Value must be one of the list below” box, which means that you can only select from the list (i.e. manual entry is not allowed). It may be worthwhile adding ‘not applicable’ or ‘not recorded’ to the picklist for when an actual/sensible value is not appropriate.
  • Set some fields as mandatory so that you do not forget to provide a value when filling out the survey form.
  • Hide any unwanted fields to make the survey forms shorter and uncluttered.
  • You can configure minimum and maximum values for the numeric fields.
  • Use the up/down arrows to change the order of the fields on the Android survey apps. Note: only the Android survey form is changed – the web version of the survey form is unchanged (for now).

With the Survey Templates button (at the top of the table of survey fields), you can copy a survey that you setup for a different client or from one of your client templates. Use that as a starting point and then modify it further as required for this client.

Any suggestions?

OTISS is constantly developing to suit our users’ requirements. Please contact us if you have suggestions for features or options that you would like to see.

BS5837 Fields

Survey & Site * Each inspection is carried out within a Survey. The Survey dictates the site for this tree.
LocationThe location of the trees and the outline of the polygons are stored as longitude/latitude coordinates in the OTISS GIS database. But they are displayed as national grid references.
Reference * A reference name or number. e.g. T01, G14.
Reference2A TPO number, other reference(s) or tag number.
SpeciesA species selected from a list of tree species. The Common Species and the Estate Species are are presented as a single list of species. If the Tree Structure is a Group, Hedge, Shrubs or Woodland, then you can record multiple species and a variety and numTrees for each one.
VarietyA variety or cultivar (text).
Tree StructureOne of: Tree, Multi-stemmed tree, Group, Hedge, Stump, etc. This field determines whether the icon is a point or a polygon.
Life Stage (Age Class)One of: Newly Planted, Young, Early Mature, Mature, Over Mature, Veteran.
Life ExpectancyEstimate life expectancy or “remaining contribution” in years, e.g. 10+, 20+, etc.
Number of StemsNumber of stems in a multi-stemmed tree. Used for calculating the RPA.

If the Structure is a Group, Hedge, Shrubs or Woodland, then the NumTrees for each species are automatically added up and the total stored in the this field for the group.
Stem diameter(s)The measured stem diameter. For multi-stemmed trees, the user can provide a list of stem diameters or an average stem diameter. Used for calculating the RPA.
RPA Area and Radius * The RPA is calculated (as define din BS5837) from the number of stems and stem diameters. This field is read-only.
HeightMeasured height of the tree.
Mature/Ultimate HeightWe use data from the NHBC Chapter 4.2, “Building near trees.” to provide an initial estimate for the expected mature height of this species. This field can then be updated to provide a revised estimate based on local site conditions.
Crown Spread: N/E/S/WMeasured crown spread for the four compass points.
Crown ClearanceMeasured height of the crown canopy from ground level.
Lowest branch Height and Direction.Measured height of the lowest branch from ground level, and the direction of growth – i.e. N/S/E/W.
Survey Notes1
Survey Notes2
Survey Notes3
Detailed notes of what was seen during this inspection. Three separate multiline text fields.
pConditionA summary of the Physiological Condition: good, fair, poor, diseased, dead
sConditionA summary of the Structural Condition: good, fair, poor, collapsing, decaying
CustomText1A configurable text field (max 50 letters).
CustomText2A configurable text field (max 50 letters).
CustomText3A configurable text field (max 50 letters).
CustomNum1A configurable decimal number.
CustomNum2A configurable decimal number.
CustomNum3A configurable decimal number.
Retention CategoryThe BS5837 category: A, B, C, U and the sub categories ‘arboricultural’, ‘landscape’ and ‘cultural’.
Pre-construction recommendationA set of pre-construction management recommendations.
Mid-construction recommendationA set of mid-construction management recommendations.
Post-construction recommendationA set of post-construction management recommendations.
Additional CommentsA set of additional comments about this tree and the proposed development.
Date Inspected * The date on which the item was inspected.
User Name * The name of the person who carried out the inspection.