TRII CONSULTANCY LTD.

(pronounced: /trɪɪ/ “ee” as in tree)

Arboricultural consultants and expert witnesses specialising in the English planning system and development applications, health and safety risk assessment and management plans, servicing the south-east of England and broader areas.


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About our work

Specialists in high quality, bespoke arboricultural consultancy. We work with you every step of the way.

We produce expert arboricultural reports and plans for tree health and safety risk management, planning, and development. We are independent of tree work practitioners, as we do not carry out any form of tree pruning or felling. 


The Director and Principal Consultant, Ben Oates, began caring for trees in 1994 as a climbing arborist, undertaking all aspects of the tree surgery craft. Since 2000, Ben has worked with local planning authorities as a tree officer for ten years and as a consultant in the private sector since 2011.

For planning applications, our work follows British Standards BS 5837, and specified tree works conform to BS 3998. Professional Indemnity Insurance covers TRII Consultancy Ltd.

A man dressed in a blue top, and orange and black trousers cutting down a tree from the top.

Our consultancy services

Our range of high-level specialist consultancy services in south-east England covers all aspects from mortgage reports to proofs of evidence at public inquiry.


Our fee structure is transparent and competitive.


We conduct risk assessments following sector recognised systematic and balanced systems inline with international standards.


Our planning advice follows the National Planning Policy Framework (NPPF), British Standards Institution (BSI), Natural England and Forestry Commission and governmental guidance.

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Planning and development

Specialist tree quality and value assessment to BS 5837 Trees in relation to design, demolition, and construction – Recommendations. We produce arboricultural impact assessments, reports supporting planning applications, tree preservation orders and conservation areas. Our plans are produced using AutoCAD, and the trees are plotted on-site using GPS. We produce appeal statements and attend appeal hearings and inquiries.

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Risk Assessment

Are you concerned about the safety of a tree or trees in your garden or large estate? Are you looking to discharge your duty of care? We can help.

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