Work at Height Regs

Work at Height Regulations and tree climbing surveys for bats

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At BATS RTS we have a somewhat unique experience and insight when it comes to surveying trees for bats. With our experience of both the ecological and arboricultural industries, we would like to start a discussion about tree climbing surveys for bats. Specifically, whether ecologists are compliant with the legislation and guidance. This post is one of a series that aims to improve the knowledge of tree climbing ecologists. We hope that this discussion will increase safety when planning and undertaking tree surveys for bats.

Our first post discussed the implications of the revised Industry Code of Practice for Arboriculture ‘Tree Work at Height’ and the requirement for climbers to use a ‘backup’ line.   

In this post we will look at a different part of the Work at Height Regulations and the Industry Code of Practice. This post is not intended to be legal advice. We recommend that those undertaking tree climbing surveys familiarise themselves with the legislation and guidance.

Work at Height Hierarchy

When planning and undertaking work, the Work at Height Regulations and Industry Code of Practice (see page 24) set out the work at height hierarchy – AVOID, PREVENT and MINIMISE. Anyone planning or undertaking work should consider each in turn, only progressing if there is sufficient justification. We will examine each in turn below and discuss how this applies to the climbing ecologist.


Regulation 6 (2): “Every employer shall ensure that work is not carried out at height where it is reasonably practicable to carry out the work safely otherwise than at height.”

Simple really. If you can avoid working at height, you should. Let’s look at an example from arboriculture. It is not always necessary to work at height to fell a tree. However, there are certain situations where work at height cannot be avoided. For example, felling a tree in a tight space or above a delicate ‘target’ such as a greenhouse. In the second example, it may be possible to undertake some work from the ground (e.g. removing lower branches), but eventually an arborist has to work at height to dismantle the tree without damaging the greenhouse. 

In ecology things are not as clear. How do you currently justify the need to work at height? I would guess that you haven’t given this any thought. However, to comply with the Work at Height Regulations, you need to consider and justify any work before leaving the ground.

Let’s examine the wording of the legislation. Before deciding to work at height, you have to consider what is reasonably practicable when surveying trees for bats. ‘Reasonably practicable’ features in various pieces of legislation and is open to interpretation. Essentially it balances the risk against the cost, time and difficulty of protective measures. It is worth noting that reasonably practicable is not ‘all that is possible’. This provides flexibility in approach to certain tasks, informed by a Responsible and/or Competent person (we will examine these roles in more detail in the next blog post).

Identify the questions

To help us in the reasonably practicable decision, we need to identify what ‘questions’ we are trying to answer. These may include: Is the feature suitable for bats? Is it a bat roost? Are bats present? What species of bat? Type/nature of roost? 

It would then be worth asking yourself, could you answer the question(s) without working at height? If the answer is yes, then perhaps you shouldn’t be working at height.

As I write this, I can hear tree climbing ecologists shouting at me: … but Jim, climbing surveys are so much better as they save time, reduce costs and produce better results … and I agree with you. I thoroughly enjoy climbing trees and have spoken at many conferences outlining the limitations with current survey methods, including emergence/re-entry surveys.

Before I cause too much despair, let’s look at our industry guidance and see if that offers any rays of hope.


Industry guidance does help us in our decision-making process.  Chapter 7 of Bat Roosts in Trees from the Bat Tree Habitat Key discusses the advantages and disadvantages of different surveillance techniques. The guidance recommends ‘close-inspection’ is used where reasonably practicable, because it is the only method that:

  • Can inform an appraisal of suitability.
  • Can be repeated in all seasons.
  • Detect field-signs.
  • Will reliably detect the presence and absence of competitors.

The big question!

Can we use this to help us justify work at height when surveying trees for bats? In some cases, I think so.

Considering both the Work at Height Regulations and this guidance from the Bat Tree Habitat Key, I would suggest the more of the above points you hit, the stronger the justification you have. For example, if you were inspecting a tree for the first time (to confirm suitability), in winter (no alternative methods available at this time of year), to the Bat Tree Habitat Key standard (including recording field signs and competitors) work at height could be justified. 

The justification may be weaker on subsequent trips (because you have already established suitability) or in summer (as alternative survey methods are available). Equally the justification may be weak if you do not record trees to the Bat Tree Habitat Key standard; if you are just recording the presence/absence of bats, you can achieve this by an emergence survey (not to mention that counting can be unreliable from close inspection). 

Each time you are planning and undertaking work, there is a need to justify work at height. Don’t rely on the previous justification.


Regulation 6 (3): “Where work is carried out at height, every employer shall take suitable and sufficient measures to prevent, so far as is reasonably practicable, any person falling a distance liable to cause personal injury.”

The legislation is clear. If you can justify the need to work at height, the next consideration is whether you can prevent falls. The use of appropriate equipment, e.g. Mobile Elevated Work Platform (MEWP) or scaffold, can help prevent a fall.

Regulation 7 (1) (a): “Every employer, in selecting work equipment for use in work at height, shall give collective protection measures priority over personal protection measures.”

Collective measures bring two main benefits. They are capable of protecting more than one person and, once properly installed, they do not require any action to make sure they still work (i.e. they are passive). 

When planning tree surveys for bats, are you currently considering fall prevention and collective measures? My experience of the ecological industry suggests that this stage is often ignored. Whilst it is permissible to move onto the next step (minimise), there needs to be an appropriate consideration and justification for this. Appropriate justification for this when surveying trees for bats may include:

  • Site access – e.g. working on greenfield sites presents a challenge on ingress and egress to the tree.
  • Duration and frequency of use – A Mobile Elevated Work Platform or scaffold comes at a cost. How long will the ecologist be exposed to this risk? Is the extra costs proportionate to risk?

Each time you are planning and undertaking work, there is a need to consider fall prevention and collective measures. In particular, if you typically use site access as the justificaiton not to use fall prevention and collective measures be mindful of any changes (e.g. development of site) that may nullify any previous justification.


Regulation 6 (5) (a) (i): “Where the measures taken under paragraph (4) do not eliminate the risk of a fall occurring, every employer shall so far as is reasonably practicable, provide sufficient work equipment to minimise the distance and consequences.”

This is where the use of climbing equipment (including a backup) and industry guidance for appropriate climbing techniques (e.g. no more than 500mm slack in system) come into effect.

I won’t say any more on this, as I am sure you are all aware and compliant with this section.


We urge all ecologists to consider the requirements of the Work at Height Regulations, specifically:

  • Ensure that you consider the Work at Height Hierarchy when planning tree surveys for bats. Record your justification if you choose to work at height.
  • Follow the Bat Tree Habitat Key guidance when undertaking close-inspections (this will help with your work at height justification). 
  • Consider the use of collective protection measures (platforms/scaffolding) before personal protection (tree climbing equipment). Record your justification if not using collective protection measures.
  • Follow industry guidance to minimise the potential distance and consequence of a fall.

Next time

Next time will investigate the roles and responsibilities when undertaking tree climbing operations.

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