Ecological Clerk of Works

The Role of an Ecological Clerk of Works

An ecological clerk of works, commonly referred to as an ECoW, is a qualified ecological consultant appointed to provide on-site ecological supervision and advice during construction, demolition, enabling works or vegetation management.

Their role is to ensure that the work being carried out on site proceeds in compliance with wildlife legislation, planning consent commitments, undertakings made in ecological reports submitted with the planning application and any European protected species (EPS) licence conditions that apply to the development.

The ECoW acts as the critical link between the ecological assessments and reports produced before planning permission was granted and the real-world construction activity that takes place on site.

Without that link, there is no reliable mechanism to ensure that the mitigation measures agreed with the local planning authority are actually implemented, or that unforeseen ecological issues encountered during construction are handled correctly in real time. 

Why is an ECoW Needed?

Local planning authorities routinely attach planning requirements to consents for development on sites where ecology surveys have identified protected species, sensitive habitats such as ancient woodland or biodiversity net gain commitments that need to be managed during construction.

These conditions may require pre-commencement checks for protected species before certain works begin, ecological supervision of vegetation clearance or topsoil stripping, a watching brief during groundworks near known habitat features, compliance monitoring and reporting at agreed intervals during the build programme, or confirmation that biodiversity net gain habitat creation works have been carried out as specified to enhance biodiversity and nature conservation.

Where a development is being carried out under a European protected species mitigation licence, for example, a bat licence issued by Natural England for works affecting a bat roost, or a licence for great crested newts for works affecting a pond, the licence conditions will typically specify the involvement of a suitably licensed ecological consultant on site during the relevant works. This is not a discretionary requirement.

Failure to have a qualified ecologist present when licence conditions require it constitutes a breach of the licence, which can expose the developer and contractor to potential problems including significant legal, financial and reputational risk.

Beyond formal environmental legislation and licence requirements, the practical value of having an ecological consultant on site is that ecological issues rarely respect the project programme.

A nesting bird encountered during vegetation clearance in spring, a badger sett discovered during groundworks, or a slow worm found under debris during site preparation; all of these require an immediate, competent response.

An ECoW plays a key role in providing that response in real time, attending site meetings, using problem-solving skills to advise the site team on what can and cannot proceed, and documenting the outcome in a way that adheres to nature conservation regulations and satisfies the local planning system.

Ecological Surveys: The Calendar and Construction Timing

One of the most valuable contributions an ecological consultant makes to a construction project is helping the programme manager understand how the ecology survey calendar affects when certain works can lawfully take place.

Many ecological activities – surveys, watching briefs, species translocation – can only be carried out at specific times of year, and construction activities that disturb habitats or vegetation must be planned carefully in relation to these constraints. The key seasonal restrictions most commonly relevant to development sites are as follows.

Vegetation clearance, including the removal of scrub, hedgerows and long grassland, must be carefully planned around the bird nesting season, which runs from approximately March to August.

While it is not unlawful to clear vegetation during this period, it is an offence under the Wildlife and Countryside Act 1981 to damage, destroy or take the nest of any wild bird while that nest is in use or being built.

Pre-clearance checks by a qualified ecological consultant are essential during the nesting season, and where active nests are found, clearance must be halted in the affected area until the nest is no longer in active use.

Bat surveys for planning purposes can only be completed during the active season, broadly April to October, with the core survey season running from May to September.

Where a development requires a bat mitigation licence, the licence cannot be implemented until the survey evidence is confirmed and the licence issued, and licence conditions will specify when certain works affecting roosts can take place.

Great crested newt surveys must be carried out between mid-March and mid-June. Reptile surveys and translocation are most effectively carried out between March and May and August to October.

Badger surveys should ideally be carried out between October and February when vegetation is lower, though sett checks can be carried out year-round. Water vole surveys should be conducted between April and October.

Understanding these ecological surveys and constraints and planning the construction programme around them, rather than discovering them when work is already underway, is one of the most cost-effective contributions a good ecology consultancy makes to a development project and nature conservation.

What Does an ECoW do?

The basic functionalities of an ECoW will depend on the nature of the development, the ecological conditions on site, other third party features and the terms of any planning stipulations or licence requirements. In general, the role covers the following areas:

Pre-Construction Checks and Site Induction

Before certain works can begin, the ECoW will carry out pre-commencement checks to confirm the baseline ecological conditions on site.

These site-specific checks assess whether protected species are present in areas due to be disturbed by the first phase of works, confirm that vegetation clearance can proceed lawfully and safely, and identify any ecological features requiring protective fencing or exclusion zones before the contractor moves on site. Regular record keeping is another part of this important role.

The ECoW will also conduct site inductions for the construction team, ensuring that all operatives understand what species and habitats may be present on site, what they are legally required to do if they encounter them, who to contact if an unexpected ecological issue arises, and what construction activities are restricted or prohibited in specific areas while adhering to health and safety requirements.

Species Management and Translocation

Where planning stipulations, licence conditions or ecological method statements require protected species to be handled, moved or excluded from the working area before construction begins, a licensed ecological consultant must carry out or directly supervise this work.

Common examples include the installation and checking of reptile drift fencing and pitfall traps ahead of construction, the careful removal and relocation of reptiles or amphibians from the working area, the implementation of bat roost access exclusion ahead of demolition or conversion works, the supervision of badger sett closure programmes and the translocation of protected plant species.

Construction Phase Monitoring and Watching Briefs

Throughout the construction phase, the ECoW monitors site activities to ensure that agreed ecological mitigation measures are being implemented correctly, that the site team is observing the ecological constraints identified in pre-construction reports, and that any new ecological issues emerging during construction are identified and addressed promptly.

The ECoW maintains the big picture of the site via detailed records of all site visits, observations and decisions, which are used to compile the compliance reports required to discharge relevant planning constraints and comply with the planning process.

A watching brief is a specific form of on-site monitoring in which the ECoW is present during works that carry a particular risk of encountering protected species or damaging sensitive habitats, for example, when vegetation is being cleared near a known bat roost, when topsoil is being stripped from an area with recorded reptile records, or when groundworks are taking place near a watercourse with otter activity.

The ECoW has authority to halt works if potential problems arise due to an ecological issue.

Liaison with Local Authorities and Regulators

The ECoW acts as the point of contact between the site team and the relevant ecological regulatory bodies during the construction phase.

This includes communicating with the local planning authority on the discharge of ecological planning requirements, liaising with Natural England or equivalent bodies where licence conditions apply, and providing the compliance documentation and data analysis required by each body to confirm that the works have been carried out as agreed.

Construction Environmental Management Plan

For larger or more complex developments, the ECoW will typically contribute to or take a lead role in producing the Construction Environmental Management Plan (CEMP), which sets out how environmental issues and risks during the construction phase, including ecological risks, will be identified, controlled and monitored.

The CEMP is often required to be submitted to and approved by the local planning authority before construction begins, and the ECoW’s role in its preparation ensures that the ecological content is accurate, proportionate and practically deliverable by the construction team.

Post-Construction Reporting

Following the completion of works, the ECoW compiles a formal report documenting how ecological planning requirements and licence requirements have been met.

This report is submitted to the local planning authority or the relevant licensing body to discharge the relevant conditions and confirm that the development has been carried out in compliance with the agreed ecological management framework.

Qualifications and Accreditation

The ECoW role requires a combination of ecological field knowledge, familiarity with UK wildlife legislation, excellent working knowledge of construction environments, problem-solving skills and the practical ability to communicate effectively with contractors and project managers under programme pressure.

Not all qualified ecologists are well suited to the role, and not all have the species handling licences required for certain types of protected species work.

Until recently there was no formal accreditation scheme specific to the ECoW role. In Winter 2025, the Chartered Institute of Ecology and Environmental Management (CIEEM) launched a dedicated ECoW accreditation scheme, initially available to CIEEM members.

The scheme was developed in direct response to sector-wide calls for clearer and more consistent standards in ECoW practice.

Accreditation under the scheme provides developers, contractors and local planning authorities with a recognised measure of competence and professional standing for ecologists working in ECoW roles.

When commissioning an ECoW service, look for an ecology consultancy whose ecologists hold CIEEM membership, hold the relevant class or individual species licences issued by Natural England or the equivalent devolved authority, and have demonstrable experience of working in construction environments on projects similar in type and scale to yours.

The ECoW and the Wider Ecology Process

A clerk of works ECoW does not replace the surveys, assessments and reports produced during the planning stage: it builds directly on them to ensure works are carried out correctly.

The ECoW’s starting point is always the ecological survey reports, the ecological impact assessment, the habitat management and monitoring plan, the environmental statement (where one was required) and any licence documents associated with the development.

These documents set out what was found, what was agreed and what must be done. The ECoW’s job is to make sure that what was agreed actually happens on the ground.

For this reason, appointing a clerk of works ECoW from the same ecology consultancy that carried out the planning stage surveys is often the most efficient approach from a project management viewpoint.

The ecologist already knows the site, understands the ecological issues that were identified, is familiar with the nature conservation commitments made in the reports they produced, and can transition smoothly from the planning phase to the construction phase without the time and cost involved in a new consultant getting up to speed.

Equally, if you are a contractor or project manager who has inherited a site where the planning stage ecology was carried out by another firm, an ECoW with the relevant experience can review the existing documentation, identify the key requirements and be ready to provide effective on-site support with nature conservation within a short lead time. 

Engaging Experienced Consultants

The most common mistake developers and project managers make with clerk of works ECoW appointments is leaving them too late.

Pre-construction ecological checks must be completed before certain works can start to identify potential problems, and if the ecologist has not been briefed, read the relevant documents and agreed the programme with the site team in advance, delays are almost inevitable.

The right time to make an ECoW appointment is at the same time as the construction programme is being finalised, before the contractor mobilises, so that the ecological calendar, planning consent commitments, programme constraints and the site team’s responsibilities are all understood and agreed from day one.

Experienced consultants play a key role: they can provide advice on a range of environmental issues and offer project management skills to help your scheme through the planning system.

Use our free service to get fast, no-obligation quotes from trusted ecological consultancies in our network.

Fill in the form at the top of this page, and we will connect you with a qualified ecological consultant who can provide ECoW support for your development and help keep your project on the right side of wildlife legislation throughout the construction phase.