A BS5837 tree survey is an assessment of the trees on and around a site where building work is planned, carried out to BS5837:2012, the British Standard for trees and development. It records what is growing on the site, grades each tree for quality, and maps the ground the roots need, so a design can be shaped around the trees worth keeping. Councils validate planning applications, and on a site with trees they will usually ask for this survey before the application moves forward. If you are planning an extension, a new build or any other development near trees, this is the report you will be asked to provide.
The survey schedule: a record of what is there
The heart of the document is the survey schedule, a table with one entry per tree or group of trees. For each entry our surveyors record the species, the size of the tree, its condition and anything notable about its structure, with a management recommendation where one is needed. Every tree gets a reference number matched to a numbered plan, so it is clear on site which tree is which.
The schedule is a statement of fact about the trees as they stand. It is most useful early, before the layout is fixed, because it tells the designer which parts of the site are genuinely available to build on.
The A, B, C and U grades
BS5837:2012 places every surveyed tree into one of four categories:
- Category A: trees of high quality, the ones a design should work hardest to keep.
- Category B: trees of moderate quality, still worth retaining where the design allows.
- Category C: trees of low quality, which carry less weight in planning decisions.
- Category U: trees in such poor condition that they cannot realistically be retained.
The grading matters because it shapes the conversation with the council: losing a few category C trees is a very different proposition from removing a category A tree.
Root protection areas and the tree constraints plan
For each retained tree the standard sets out a root protection area: an area of ground around the stem that the roots need and that construction should stay out of. The standard treats the ground around a tree as part of the tree, not as spare space.
The tree constraints plan draws all of this onto the site plan, with each tree plotted in position and its root protection area shown. A designer can then see at a glance how much of the site the trees actually occupy, below ground as well as above it.
Impact assessment, method statement and protection plan
Once a layout exists, three further documents may be needed, and this is usually where a council’s requests come in.
- The arboricultural impact assessment takes the proposed design and sets out what it means for each tree: which are removed, which are retained, and where the works come close to a root protection area.
- The arboricultural method statement explains how any work near retained trees will be carried out so they are not harmed.
- The tree protection plan is a drawing showing where protection will be put in place and kept for the duration of the build.
Which of these a council asks for, and at what stage, varies from council to council and from application to application. Some want the full set before they will validate the application. Others grant permission with a condition that the method statement and protection plan are approved before work starts. Check with your council, or ask us and we will tell you what your application is likely to need.
When do you need one, and what about protected trees?
In practice you need one whenever you make a planning application on land with trees on it or overhanging it, and often when trees on neighbouring land stand close to the boundary. It is worth commissioning before the design is settled, because moving a building on paper is far easier than moving it on site.
Protected trees need extra care. Trees covered by a Tree Preservation Order need council consent before any works, and trees in a conservation area need six weeks written notice to the council. Penalties for unauthorised works on protected trees can include unlimited fines, so check before anything is cut. Our free checker at /is-my-tree-protected/ reads the national planning dataset and gives an indicative answer; the council’s register is the definitive record. This is general information, not legal advice.
A note on how we work. Our BS5837 surveys are priced and delivered on their own: the findings are what the trees need, and you are free to take the report to any contractor or consultant you choose. If it suits you to keep everything with one firm, we can also carry out any agreed tree work as an ARB Approved Contractor (AC2637). We are Constructionline Gold registered, carry £1m professional indemnity insurance, and our BS5837 tree survey service covers Preston, Lancashire and the North West as part of our wider tree surveys work.
Not sure whether your project needs one? Use the free scope check form at our tree surveys page, or call the office on 07884 274693. We quote within one working day, arrange survey visits within days, not weeks, and the price we quote is the price you pay.
